SERVER-48775 Move all Sharding unit-tests that assume a MongoD to the db/s directory

With this change there are no more references from mongo/s (which is
code common between MongoS and MongoD) and mongo/db/s (which is code
specific for MongoD only).

44 files changed, 1608 insertions, 156 deletions

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 642e54fbb7a..adab7bc70e4 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -1507,6 +1507,17 @@ env.Library(
 )
 
 env.Library(
+    target='rs_local_client',
+    source=[
+        'rs_local_client.cpp',
+    ],
+    LIBDEPS_PRIVATE=[
+        '$BUILD_DIR/mongo/db/repl/repl_coordinator_interface',
+        'dbdirectclient',
+    ],
+)
+
+env.Library(
     target='keys_collection_document',
     source=[
         'keys_collection_document.cpp',
@@ -1523,11 +1534,13 @@ env.Library(
         'keys_collection_client_direct.cpp',
     ],
     LIBDEPS=[
-        'keys_collection_document',
-        'logical_time',
         '$BUILD_DIR/mongo/s/catalog/sharding_catalog_client',
-        '$BUILD_DIR/mongo/s/client/rs_local_client',
         '$BUILD_DIR/mongo/s/client/shard_interface',
+        'keys_collection_document',
+        'logical_time',
+    ],
+    LIBDEPS_PRIVATE=[
+        'rs_local_client',
     ],
 )
 
@@ -1635,11 +1648,11 @@ env.Library(
         'logical_clock_test_fixture.cpp',
     ],
     LIBDEPS= [
+        '$BUILD_DIR/mongo/db/auth/authmocks',
+        '$BUILD_DIR/mongo/util/clock_source_mock',
+        's/sharding_mongod_test_fixture',
         'signed_logical_time',
         'vector_clock',
-        '$BUILD_DIR/mongo/db/auth/authmocks',
-        '$BUILD_DIR/mongo/s/sharding_mongod_test_fixture',
-        '$BUILD_DIR/mongo/util/clock_source_mock'
     ],
 )
 
@@ -1663,7 +1676,6 @@ env.Library(
         'service_context_d_test_fixture.cpp',
     ],
     LIBDEPS=[
-        '$BUILD_DIR/mongo/unittest/unittest',
         'service_context_test_fixture',
     ],
     LIBDEPS_PRIVATE=[
@@ -1989,7 +2001,7 @@ env.CppLibfuzzerTest(
         '$BUILD_DIR/mongo/transport/service_entry_point',
         '$BUILD_DIR/mongo/transport/transport_layer_mock',
         '$BUILD_DIR/mongo/db/repl/replmocks',
-        '$BUILD_DIR/mongo/unittest/unittest/',
+        '$BUILD_DIR/mongo/unittest/unittest',
     ],
 )
 
diff --git a/src/mongo/db/keys_collection_client_direct.h b/src/mongo/db/keys_collection_client_direct.h
index 6e96d8e94ed..3b101d99167 100644
--- a/src/mongo/db/keys_collection_client_direct.h
+++ b/src/mongo/db/keys_collection_client_direct.h
@@ -32,9 +32,8 @@
 #include <memory>
 #include <string>
 
-#include "mongo/base/status.h"
 #include "mongo/db/keys_collection_client.h"
-#include "mongo/s/client/rs_local_client.h"
+#include "mongo/db/rs_local_client.h"
 
 namespace mongo {
 
diff --git a/src/mongo/db/logical_clock_test_fixture.h b/src/mongo/db/logical_clock_test_fixture.h
index 4b3322d406b..4602ae629cd 100644
--- a/src/mongo/db/logical_clock_test_fixture.h
+++ b/src/mongo/db/logical_clock_test_fixture.h
@@ -29,8 +29,7 @@
 
 #pragma once
 
-#include "mongo/s/sharding_mongod_test_fixture.h"
-#include "mongo/unittest/unittest.h"
+#include "mongo/db/s/sharding_mongod_test_fixture.h"
 
 namespace mongo {
 
diff --git a/src/mongo/db/pipeline/SConscript b/src/mongo/db/pipeline/SConscript
index d7841f55b3c..a45860c9c15 100644
--- a/src/mongo/db/pipeline/SConscript
+++ b/src/mongo/db/pipeline/SConscript
@@ -402,7 +402,6 @@ env.CppUnitTest(
         '$BUILD_DIR/mongo/db/service_context_d_test_fixture',
         '$BUILD_DIR/mongo/db/service_context_test_fixture',
         '$BUILD_DIR/mongo/executor/thread_pool_task_executor_test_fixture',
-        '$BUILD_DIR/mongo/s/catalog_cache_test_fixture',
         '$BUILD_DIR/mongo/s/is_mongos',
         '$BUILD_DIR/mongo/s/query/router_exec_stage',
         '$BUILD_DIR/mongo/s/sharding_router_test_fixture',
diff --git a/src/mongo/db/pipeline/process_interface/SConscript b/src/mongo/db/pipeline/process_interface/SConscript
index aa783988fd3..5c74b6f7999 100644
--- a/src/mongo/db/pipeline/process_interface/SConscript
+++ b/src/mongo/db/pipeline/process_interface/SConscript
@@ -120,7 +120,7 @@ env.CppUnitTest(
         '$BUILD_DIR/mongo/db/query/query_test_service_context',
         '$BUILD_DIR/mongo/db/service_context_test_fixture',
         '$BUILD_DIR/mongo/db/vector_clock_mongod',
-        '$BUILD_DIR/mongo/s/catalog_cache_test_fixture',
+        '$BUILD_DIR/mongo/s/sharding_router_test_fixture',
         'mongos_process_interface',
         'shardsvr_process_interface',
     ]
diff --git a/src/mongo/db/rs_local_client.cpp b/src/mongo/db/rs_local_client.cpp
new file mode 100644
index 00000000000..253efa13eca
--- /dev/null
+++ b/src/mongo/db/rs_local_client.cpp
@@ -0,0 +1,155 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/rs_local_client.h"
+
+#include "mongo/db/curop.h"
+#include "mongo/db/dbdirectclient.h"
+#include "mongo/db/repl/repl_client_info.h"
+#include "mongo/db/repl/repl_set_config.h"
+#include "mongo/db/repl/replication_coordinator.h"
+#include "mongo/rpc/get_status_from_command_result.h"
+#include "mongo/rpc/unique_message.h"
+#include "mongo/util/scopeguard.h"
+
+namespace mongo {
+
+void RSLocalClient::_updateLastOpTimeFromClient(OperationContext* opCtx,
+                                                const repl::OpTime& previousOpTimeOnClient) {
+    const auto lastOpTimeFromClient =
+        repl::ReplClientInfo::forClient(opCtx->getClient()).getLastOp();
+
+    if (lastOpTimeFromClient.isNull() || lastOpTimeFromClient == previousOpTimeOnClient) {
+        return;
+    }
+
+    stdx::lock_guard<Latch> lk(_mutex);
+    if (lastOpTimeFromClient >= _lastOpTime) {
+        // It's always possible for lastOpTimeFromClient to be less than _lastOpTime if another
+        // thread started and completed a write through this ShardLocal (updating _lastOpTime)
+        // after this operation had completed its write but before it got here.
+        _lastOpTime = lastOpTimeFromClient;
+    }
+}
+
+repl::OpTime RSLocalClient::_getLastOpTime() {
+    stdx::lock_guard<Latch> lk(_mutex);
+    return _lastOpTime;
+}
+
+StatusWith<Shard::CommandResponse> RSLocalClient::runCommandOnce(OperationContext* opCtx,
+                                                                 StringData dbName,
+                                                                 const BSONObj& cmdObj) {
+    const auto currentOpTimeFromClient =
+        repl::ReplClientInfo::forClient(opCtx->getClient()).getLastOp();
+    ON_BLOCK_EXIT([this, &opCtx, &currentOpTimeFromClient] {
+        _updateLastOpTimeFromClient(opCtx, currentOpTimeFromClient);
+    });
+
+    try {
+        DBDirectClient client(opCtx);
+
+        rpc::UniqueReply commandResponse =
+            client.runCommand(OpMsgRequest::fromDBAndBody(dbName, cmdObj));
+
+        auto result = commandResponse->getCommandReply().getOwned();
+        return Shard::CommandResponse(boost::none,
+                                      result,
+                                      getStatusFromCommandResult(result),
+                                      getWriteConcernStatusFromCommandResult(result));
+    } catch (const DBException& ex) {
+        return ex.toStatus();
+    }
+}
+
+StatusWith<Shard::QueryResponse> RSLocalClient::queryOnce(
+    OperationContext* opCtx,
+    const ReadPreferenceSetting& readPref,
+    const repl::ReadConcernLevel& readConcernLevel,
+    const NamespaceString& nss,
+    const BSONObj& query,
+    const BSONObj& sort,
+    boost::optional<long long> limit) {
+    auto replCoord = repl::ReplicationCoordinator::get(opCtx);
+
+    if (readConcernLevel == repl::ReadConcernLevel::kMajorityReadConcern) {
+        // Set up operation context with majority read snapshot so correct optime can be retrieved.
+        opCtx->recoveryUnit()->setTimestampReadSource(RecoveryUnit::ReadSource::kMajorityCommitted);
+        Status status = opCtx->recoveryUnit()->obtainMajorityCommittedSnapshot();
+
+        // Wait for any writes performed by this ShardLocal instance to be committed and visible.
+        Status readConcernStatus = replCoord->waitUntilOpTimeForRead(
+            opCtx, repl::ReadConcernArgs{_getLastOpTime(), readConcernLevel});
+        if (!readConcernStatus.isOK()) {
+            return readConcernStatus;
+        }
+
+        // Inform the storage engine to read from the committed snapshot for the rest of this
+        // operation.
+        status = opCtx->recoveryUnit()->obtainMajorityCommittedSnapshot();
+        if (!status.isOK()) {
+            return status;
+        }
+    } else {
+        invariant(readConcernLevel == repl::ReadConcernLevel::kLocalReadConcern);
+    }
+
+    DBDirectClient client(opCtx);
+    Query fullQuery(query);
+    if (!sort.isEmpty()) {
+        fullQuery.sort(sort);
+    }
+    fullQuery.readPref(readPref.pref, BSONArray());
+
+    try {
+        std::unique_ptr<DBClientCursor> cursor =
+            client.query(nss, fullQuery, limit.get_value_or(0));
+
+        if (!cursor) {
+            return {ErrorCodes::OperationFailed,
+                    str::stream() << "Failed to establish a cursor for reading " << nss.ns()
+                                  << " from local storage"};
+        }
+
+        std::vector<BSONObj> documentVector;
+        while (cursor->more()) {
+            BSONObj document = cursor->nextSafe().getOwned();
+            documentVector.push_back(std::move(document));
+        }
+
+        return Shard::QueryResponse{std::move(documentVector),
+                                    replCoord->getCurrentCommittedSnapshotOpTime()};
+    } catch (const DBException& ex) {
+        return ex.toStatus();
+    }
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/rs_local_client.h b/src/mongo/db/rs_local_client.h
new file mode 100644
index 00000000000..233732b5c8e
--- /dev/null
+++ b/src/mongo/db/rs_local_client.h
@@ -0,0 +1,99 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/repl/optime.h"
+#include "mongo/platform/mutex.h"
+#include "mongo/s/client/shard.h"
+#include "mongo/util/hierarchical_acquisition.h"
+
+namespace mongo {
+
+/**
+ * Implements the support for "read your own write" when run on a node of a replica set. Can be used
+ * in the scenarios where causal consistency is not available yet.
+ */
+class RSLocalClient {
+    RSLocalClient(const RSLocalClient&) = delete;
+    RSLocalClient& operator=(const RSLocalClient&) = delete;
+
+public:
+    explicit RSLocalClient() = default;
+
+    ~RSLocalClient() = default;
+
+    /**
+     * Runs the specified command returns the BSON command response plus parsed out Status of this
+     * response and write concern error (if present).
+     */
+    StatusWith<Shard::CommandResponse> runCommandOnce(OperationContext* opCtx,
+                                                      StringData dbName,
+                                                      const BSONObj& cmdObj);
+
+    /**
+     * Warning: This method exhausts the cursor and pulls all data into memory.
+     * Do not use other than for very small (i.e., admin or metadata) collections.
+     */
+    StatusWith<Shard::QueryResponse> queryOnce(OperationContext* opCtx,
+                                               const ReadPreferenceSetting& readPref,
+                                               const repl::ReadConcernLevel& readConcernLevel,
+                                               const NamespaceString& nss,
+                                               const BSONObj& query,
+                                               const BSONObj& sort,
+                                               boost::optional<long long> limit);
+
+private:
+    /**
+     * Checks if an OpTime was set on the current Client (ie if the current operation performed a
+     * write) and if so updates _lastOpTime to the OpTime from the write that was just performed.
+     * The 'previousOpTimeOnClient' parameter is the optime that *was* the optime on this client
+     * before we ran this command through this RSLocalClient. By the time this method is called,
+     * if the optime set on the Client is different than 'previousOpTimeOnClient' then that means
+     * the command just run did a write and we should update _lastOpTime to capture the optime of
+     * the write we just did.  If the current optime on the client is the same as
+     * 'previousOpTimeOnClient' then the command we just ran didn't do a write, and we should leave
+     * _lastOpTime alone.
+     */
+    void _updateLastOpTimeFromClient(OperationContext* opCtx,
+                                     const repl::OpTime& previousOpTimeOnClient);
+
+    repl::OpTime _getLastOpTime();
+
+    // Guards _lastOpTime below.
+    Mutex _mutex = MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(0), "RSLocalClient::_mutex");
+
+    // Stores the optime that was generated by the last operation to perform a write that was run
+    // through _runCommand.  Used in _exhaustiveFindOnConfig for waiting for that optime to be
+    // committed so that readConcern majority reads will read the writes that were performed without
+    // a w:majority write concern.
+    repl::OpTime _lastOpTime{};
+};
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/SConscript b/src/mongo/db/s/SConscript
index 841cddda124..d072b62a778 100644
--- a/src/mongo/db/s/SConscript
+++ b/src/mongo/db/s/SConscript
@@ -81,6 +81,7 @@ env.Library(
         'sharding_state_recovery.cpp',
         'sharding_statistics.cpp',
         'split_chunk.cpp',
+        'shard_local.cpp',
         'split_vector.cpp',
         'start_chunk_clone_request.cpp',
         env.Idlc('migration_coordinator_document.idl')[0],
@@ -95,13 +96,11 @@ env.Library(
         '$BUILD_DIR/mongo/db/op_observer_impl',
         '$BUILD_DIR/mongo/db/ops/write_ops_exec',
         '$BUILD_DIR/mongo/db/repl/oplog',
-        '$BUILD_DIR/mongo/db/repl/repl_coordinator_interface',
         '$BUILD_DIR/mongo/db/rw_concern_d',
         '$BUILD_DIR/mongo/db/server_options_core',
         '$BUILD_DIR/mongo/db/storage/remove_saver',
         '$BUILD_DIR/mongo/db/transaction',
         '$BUILD_DIR/mongo/db/vector_clock_mongod',
-        '$BUILD_DIR/mongo/s/client/shard_local',
         '$BUILD_DIR/mongo/s/query/cluster_aggregate',
         '$BUILD_DIR/mongo/s/sharding_initialization',
         'chunk_splitter',
@@ -113,6 +112,7 @@ env.Library(
     ],
     LIBDEPS_PRIVATE=[
         '$BUILD_DIR/mongo/db/index_builds_coordinator_interface',
+        '$BUILD_DIR/mongo/db/rs_local_client',
         '$BUILD_DIR/mongo/db/session_catalog',
         '$BUILD_DIR/mongo/idl/server_parameter',
     ],
@@ -342,60 +342,40 @@ env.Library(
 )
 
 env.Library(
-    target='config_server_test_fixture',
+    target='sharding_mongod_test_fixture',
     source=[
-        'config/config_server_test_fixture.cpp',
+        'sharding_mongod_test_fixture.cpp',
     ],
     LIBDEPS=[
-        '$BUILD_DIR/mongo/s/sharding_mongod_test_fixture',
-        'sharding_catalog_manager',
+        '$BUILD_DIR/mongo/db/repl/drop_pending_collection_reaper',
+        '$BUILD_DIR/mongo/db/repl/replmocks',
+        '$BUILD_DIR/mongo/db/service_context_d_test_fixture',
+        '$BUILD_DIR/mongo/s/sharding_test_fixture_common',
+        'sharding_runtime_d',
     ],
 )
 
-env.CppUnitTest(
-    target='db_s_test',
+env.Library(
+    target='shard_server_test_fixture',
     source=[
-        'chunk_split_state_driver_test.cpp',
-        'config_server_op_observer_test.cpp',
-        'migration_session_id_test.cpp',
-        'sharding_logging_test.cpp',
-        'start_chunk_clone_request_test.cpp',
-        'type_shard_identity_test.cpp',
-        'vector_clock_config_server_test.cpp',
-        'wait_for_majority_service_test.cpp',
+        'shard_server_test_fixture.cpp',
     ],
     LIBDEPS=[
-        '$BUILD_DIR/mongo/db/auth/authmocks',
+        '$BUILD_DIR/mongo/s/catalog/dist_lock_catalog_mock',
         '$BUILD_DIR/mongo/s/catalog/dist_lock_manager_mock',
-        '$BUILD_DIR/mongo/s/sharding_router_test_fixture',
-        'chunk_splitter',
-        'config_server_test_fixture',
-        'sharding_logging',
-        'sharding_runtime_d',
-        'type_shard_identity',
+        'sharding_mongod_test_fixture',
     ],
 )
 
-env.CppUnitTest(
-    target='db_s_balancer_test',
+env.Library(
+    target='config_server_test_fixture',
     source=[
-        'balancer/balancer_chunk_selection_policy_test.cpp',
-        'balancer/balancer_policy_test.cpp',
-        'balancer/cluster_statistics_test.cpp',
-        'balancer/core_options_stub.cpp',
-        'balancer/migration_manager_test.cpp',
-        'balancer/migration_test_fixture.cpp',
-        'balancer/scoped_migration_request_test.cpp',
-        'balancer/type_migration_test.cpp',
+        'config/config_server_test_fixture.cpp',
     ],
     LIBDEPS=[
-        '$BUILD_DIR/mongo/db/auth/authmocks',
-        '$BUILD_DIR/mongo/db/read_write_concern_defaults_mock',
-        '$BUILD_DIR/mongo/db/repl/replication_info',
-        '$BUILD_DIR/mongo/util/version_impl',
-        'balancer',
-        'config_server_test_fixture',
-    ]
+        'sharding_catalog_manager',
+        'sharding_mongod_test_fixture',
+    ],
 )
 
 env.CppUnitTest(
@@ -405,18 +385,25 @@ env.CppUnitTest(
         'active_move_primaries_registry_test.cpp',
         'active_shard_collection_registry_test.cpp',
         'catalog_cache_loader_mock.cpp',
+        'chunk_split_state_driver_test.cpp',
         'migration_chunk_cloner_source_legacy_test.cpp',
         'migration_destination_manager_test.cpp',
+        'migration_session_id_test.cpp',
         'migration_util_test.cpp',
         'namespace_metadata_change_notifications_test.cpp',
         'session_catalog_migration_destination_test.cpp',
         'session_catalog_migration_source_test.cpp',
+        'shard_local_test.cpp',
         'shard_metadata_util_test.cpp',
         'shard_server_catalog_cache_loader_test.cpp',
         'sharding_initialization_mongod_test.cpp',
         'sharding_initialization_op_observer_test.cpp',
+        'sharding_logging_test.cpp',
         'split_vector_test.cpp',
+        'start_chunk_clone_request_test.cpp',
+        'type_shard_identity_test.cpp',
         'vector_clock_shard_server_test.cpp',
+        'wait_for_majority_service_test.cpp',
     ],
     LIBDEPS_PRIVATE=[
         '$BUILD_DIR/mongo/db/auth/authmocks',
@@ -427,9 +414,9 @@ env.CppUnitTest(
         '$BUILD_DIR/mongo/db/repl/mock_repl_coord_server_fixture',
         '$BUILD_DIR/mongo/db/repl/storage_interface_impl',
         '$BUILD_DIR/mongo/s/catalog/dist_lock_manager_mock',
-        '$BUILD_DIR/mongo/s/catalog/sharding_catalog_client_impl',
         '$BUILD_DIR/mongo/s/catalog/sharding_catalog_client_mock',
-        '$BUILD_DIR/mongo/s/shard_server_test_fixture',
+        'shard_server_test_fixture',
+        'sharding_logging',
         'sharding_runtime_d',
     ],
 )
@@ -450,9 +437,8 @@ env.CppUnitTest(
         '$BUILD_DIR/mongo/client/remote_command_targeter_mock',
         '$BUILD_DIR/mongo/db/auth/authmocks',
         '$BUILD_DIR/mongo/db/repl/replmocks',
-        '$BUILD_DIR/mongo/executor/network_test_env',
         '$BUILD_DIR/mongo/executor/thread_pool_task_executor_test_fixture',
-        '$BUILD_DIR/mongo/s/shard_server_test_fixture',
+        'shard_server_test_fixture',
     ],
 )
 
@@ -470,13 +456,13 @@ env.CppUnitTest(
         '$BUILD_DIR/mongo/db/auth/authmocks',
         '$BUILD_DIR/mongo/db/commands/server_status',
         '$BUILD_DIR/mongo/s/catalog/sharding_catalog_client_mock',
-        '$BUILD_DIR/mongo/s/shard_server_test_fixture',
+        'shard_server_test_fixture',
         'transaction_coordinator',
     ],
 )
 
 env.CppUnitTest(
-    target='db_s_sharding_catalog_manager_test',
+    target='db_s_config_server_test',
     source=[
         'config/initial_split_policy_test.cpp',
         'config/sharding_catalog_manager_add_shard_test.cpp',
@@ -494,10 +480,24 @@ env.CppUnitTest(
         'config/sharding_catalog_manager_remove_shard_test.cpp',
         'config/sharding_catalog_manager_shard_collection_test.cpp',
         'config/sharding_catalog_manager_split_chunk_test.cpp',
+        'balancer/balancer_chunk_selection_policy_test.cpp',
+        'balancer/balancer_policy_test.cpp',
+        'balancer/cluster_statistics_test.cpp',
+        'balancer/core_options_stub.cpp',
+        'balancer/migration_manager_test.cpp',
+        'balancer/migration_test_fixture.cpp',
+        'balancer/scoped_migration_request_test.cpp',
+        'balancer/type_migration_test.cpp',
+        'config_server_op_observer_test.cpp',
+        'vector_clock_config_server_test.cpp',
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/db/auth/authmocks',
+        '$BUILD_DIR/mongo/db/read_write_concern_defaults_mock',
+        '$BUILD_DIR/mongo/db/repl/replication_info',
+        '$BUILD_DIR/mongo/s/catalog/dist_lock_manager_mock',
         '$BUILD_DIR/mongo/util/version_impl',
+        'balancer',
         'config_server_test_fixture',
     ]
 )
diff --git a/src/mongo/db/s/collection_metadata_filtering_test.cpp b/src/mongo/db/s/collection_metadata_filtering_test.cpp
index 348cd18bfb4..ebb0d564bea 100644
--- a/src/mongo/db/s/collection_metadata_filtering_test.cpp
+++ b/src/mongo/db/s/collection_metadata_filtering_test.cpp
@@ -32,8 +32,8 @@
 #include "mongo/db/catalog_raii.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/operation_sharding_state.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/s/catalog/type_chunk.h"
-#include "mongo/s/shard_server_test_fixture.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/collection_sharding_runtime_test.cpp b/src/mongo/db/s/collection_sharding_runtime_test.cpp
index c20f65db9d0..08d6ad3edad 100644
--- a/src/mongo/db/s/collection_sharding_runtime_test.cpp
+++ b/src/mongo/db/s/collection_sharding_runtime_test.cpp
@@ -34,8 +34,8 @@
 #include "mongo/db/dbdirectclient.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/operation_sharding_state.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/wait_for_majority_service.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/util/fail_point.h"
 
 namespace mongo {
diff --git a/src/mongo/db/s/config/config_server_test_fixture.cpp b/src/mongo/db/s/config/config_server_test_fixture.cpp
index 0cbc51e25b4..de55abb2be4 100644
--- a/src/mongo/db/s/config/config_server_test_fixture.cpp
+++ b/src/mongo/db/s/config/config_server_test_fixture.cpp
@@ -51,7 +51,6 @@
 #include "mongo/db/repl/repl_settings.h"
 #include "mongo/db/repl/replication_coordinator_mock.h"
 #include "mongo/db/s/config/sharding_catalog_manager.h"
-#include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/task_executor_pool.h"
 #include "mongo/executor/thread_pool_task_executor_test_fixture.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
@@ -60,17 +59,13 @@
 #include "mongo/s/catalog/dist_lock_catalog_impl.h"
 #include "mongo/s/catalog/replset_dist_lock_manager.h"
 #include "mongo/s/catalog/sharding_catalog_client_impl.h"
-#include "mongo/s/catalog/type_changelog.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/catalog/type_collection.h"
 #include "mongo/s/catalog/type_database.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/catalog_cache.h"
 #include "mongo/s/chunk_version.h"
-#include "mongo/s/client/shard_factory.h"
-#include "mongo/s/client/shard_local.h"
 #include "mongo/s/client/shard_registry.h"
-#include "mongo/s/client/shard_remote.h"
 #include "mongo/s/config_server_catalog_cache_loader.h"
 #include "mongo/s/database_version_helpers.h"
 #include "mongo/s/grid.h"
diff --git a/src/mongo/db/s/config/config_server_test_fixture.h b/src/mongo/db/s/config/config_server_test_fixture.h
index 0c64cfca33b..ba008a827f6 100644
--- a/src/mongo/db/s/config/config_server_test_fixture.h
+++ b/src/mongo/db/s/config/config_server_test_fixture.h
@@ -30,7 +30,7 @@
 #pragma once
 
 #include "mongo/db/catalog_raii.h"
-#include "mongo/s/sharding_mongod_test_fixture.h"
+#include "mongo/db/s/sharding_mongod_test_fixture.h"
 
 namespace mongo {
 
@@ -43,18 +43,19 @@ class Shard;
 class ShardId;
 class ShardRegistry;
 class ShardType;
-template <typename T>
-class StatusWith;
 
 /**
  * Provides config-specific functionality in addition to the mock storage engine and mock network
  * provided by ShardingMongodTestFixture.
  */
 class ConfigServerTestFixture : public ShardingMongodTestFixture {
-public:
+protected:
     ConfigServerTestFixture();
     ~ConfigServerTestFixture();
 
+    void setUp() override;
+    void tearDown() override;
+
     std::shared_ptr<Shard> getConfigShard() const;
 
     /**
@@ -150,12 +151,6 @@ public:
      */
     std::vector<KeysCollectionDocument> getKeys(OperationContext* opCtx);
 
-protected:
-    /**
-     * Sets this node up as a mongod with sharding components for ClusterRole::ConfigServer.
-     */
-    void setUp() override;
-
     /**
      * Sets this node up and locks the config db in _setUp() before calling
      * initializeGlobalShardingStateForMongodForTest(). The RAII object for the database lock is
@@ -170,8 +165,6 @@ protected:
      */
     void setUpAndInitializeConfigDb();
 
-    void tearDown() override;
-
     std::unique_ptr<DistLockCatalog> makeDistLockCatalog() override;
 
     std::unique_ptr<DistLockManager> makeDistLockManager(
diff --git a/src/mongo/db/s/config/sharding_catalog_manager_remove_shard_test.cpp b/src/mongo/db/s/config/sharding_catalog_manager_remove_shard_test.cpp
index acf08255915..254afab7c12 100644
--- a/src/mongo/db/s/config/sharding_catalog_manager_remove_shard_test.cpp
+++ b/src/mongo/db/s/config/sharding_catalog_manager_remove_shard_test.cpp
@@ -39,11 +39,9 @@
 #include "mongo/db/ops/write_ops.h"
 #include "mongo/db/s/config/config_server_test_fixture.h"
 #include "mongo/db/s/config/sharding_catalog_manager.h"
-#include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/task_executor.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/rpc/metadata/tracking_metadata.h"
-#include "mongo/s/catalog/type_changelog.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/catalog/type_database.h"
 #include "mongo/s/catalog/type_shard.h"
diff --git a/src/mongo/db/s/metadata_manager_test.cpp b/src/mongo/db/s/metadata_manager_test.cpp
index dc053e3c202..760f04ea78e 100644
--- a/src/mongo/db/s/metadata_manager_test.cpp
+++ b/src/mongo/db/s/metadata_manager_test.cpp
@@ -37,6 +37,7 @@
 #include "mongo/db/jsobj.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/s/metadata_manager.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/sharding_runtime_d_params_gen.h"
 #include "mongo/db/s/sharding_state.h"
 #include "mongo/db/server_options.h"
@@ -44,7 +45,6 @@
 #include "mongo/executor/task_executor.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/client/shard_registry.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/stdx/condition_variable.h"
 #include "mongo/unittest/unittest.h"
 #include "mongo/util/assert_util.h"
diff --git a/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp b/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp
index 730a2d4af3b..446b5984c68 100644
--- a/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp
+++ b/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp
@@ -36,10 +36,10 @@
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/migration_chunk_cloner_source_legacy.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/s/catalog/sharding_catalog_client_mock.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/client/shard_registry.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/unittest/unittest.h"
 #include "mongo/util/clock_source_mock.h"
 
diff --git a/src/mongo/db/s/migration_destination_manager_test.cpp b/src/mongo/db/s/migration_destination_manager_test.cpp
index 9c5fc74de87..51aa7174b35 100644
--- a/src/mongo/db/s/migration_destination_manager_test.cpp
+++ b/src/mongo/db/s/migration_destination_manager_test.cpp
@@ -30,8 +30,7 @@
 #include "mongo/platform/basic.h"
 
 #include "mongo/db/s/migration_destination_manager.h"
-#include "mongo/s/shard_server_test_fixture.h"
-#include "mongo/unittest/unittest.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/migration_util_test.cpp b/src/mongo/db/s/migration_util_test.cpp
index 9ae0dfa8bed..f643224ccee 100644
--- a/src/mongo/db/s/migration_util_test.cpp
+++ b/src/mongo/db/s/migration_util_test.cpp
@@ -37,13 +37,12 @@
 #include "mongo/db/s/persistent_task_store.h"
 #include "mongo/db/s/shard_filtering_metadata_refresh.h"
 #include "mongo/db/s/shard_server_catalog_cache_loader.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/sharding_state.h"
 #include "mongo/db/s/wait_for_majority_service.h"
 #include "mongo/s/catalog/sharding_catalog_client_mock.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/database_version_helpers.h"
-#include "mongo/s/shard_server_test_fixture.h"
-#include "mongo/unittest/unittest.h"
 #include "mongo/util/future.h"
 
 namespace mongo {
diff --git a/src/mongo/db/s/op_observer_sharding_test.cpp b/src/mongo/db/s/op_observer_sharding_test.cpp
index 54b15903ce8..eaf8e55f78b 100644
--- a/src/mongo/db/s/op_observer_sharding_test.cpp
+++ b/src/mongo/db/s/op_observer_sharding_test.cpp
@@ -33,8 +33,8 @@
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/op_observer_sharding_impl.h"
 #include "mongo/db/s/operation_sharding_state.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/type_shard_identity.h"
-#include "mongo/s/shard_server_test_fixture.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/persistent_task_queue_test.cpp b/src/mongo/db/s/persistent_task_queue_test.cpp
index 96324d13761..6009b99860c 100644
--- a/src/mongo/db/s/persistent_task_queue_test.cpp
+++ b/src/mongo/db/s/persistent_task_queue_test.cpp
@@ -31,10 +31,9 @@
 #include "mongo/db/db_raii.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/persistent_task_queue.h"
-#include "mongo/s/shard_server_test_fixture.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/stdx/thread.h"
 #include "mongo/unittest/barrier.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/persistent_task_store_test.cpp b/src/mongo/db/s/persistent_task_store_test.cpp
index c2abcf6a7be..177fe264d1d 100644
--- a/src/mongo/db/s/persistent_task_store_test.cpp
+++ b/src/mongo/db/s/persistent_task_store_test.cpp
@@ -27,11 +27,12 @@
  *    it in the license file.
  */
 
+#include "mongo/platform/basic.h"
+
 #include "mongo/db/db_raii.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/persistent_task_store.h"
-#include "mongo/s/shard_server_test_fixture.h"
-#include "mongo/unittest/unittest.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/range_deletion_util_test.cpp b/src/mongo/db/s/range_deletion_util_test.cpp
index 0121d4b9e7c..919d723028f 100644
--- a/src/mongo/db/s/range_deletion_util_test.cpp
+++ b/src/mongo/db/s/range_deletion_util_test.cpp
@@ -37,11 +37,10 @@
 #include "mongo/db/s/persistent_task_store.h"
 #include "mongo/db/s/range_deletion_task_gen.h"
 #include "mongo/db/s/range_deletion_util.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/sharding_runtime_d_params_gen.h"
 #include "mongo/db/s/wait_for_majority_service.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/unittest/death_test.h"
-#include "mongo/unittest/unittest.h"
 #include "mongo/util/fail_point.h"
 
 namespace mongo {
diff --git a/src/mongo/db/s/session_catalog_migration_destination_test.cpp b/src/mongo/db/s/session_catalog_migration_destination_test.cpp
index 1f8e00bd3b2..68119925dfb 100644
--- a/src/mongo/db/s/session_catalog_migration_destination_test.cpp
+++ b/src/mongo/db/s/session_catalog_migration_destination_test.cpp
@@ -46,6 +46,7 @@
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/migration_session_id.h"
 #include "mongo/db/s/session_catalog_migration_destination.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/server_options.h"
 #include "mongo/db/session_catalog_mongod.h"
 #include "mongo/db/session_txn_record_gen.h"
@@ -55,9 +56,7 @@
 #include "mongo/s/catalog/sharding_catalog_client_mock.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/client/shard_registry.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/stdx/thread.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/shard_local.cpp b/src/mongo/db/s/shard_local.cpp
new file mode 100644
index 00000000000..6b18e6fa849
--- /dev/null
+++ b/src/mongo/db/s/shard_local.cpp
@@ -0,0 +1,190 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/s/shard_local.h"
+
+#include "mongo/client/remote_command_targeter.h"
+#include "mongo/db/catalog/index_catalog.h"
+#include "mongo/db/catalog_raii.h"
+#include "mongo/db/concurrency/write_conflict_exception.h"
+#include "mongo/db/index/index_descriptor.h"
+#include "mongo/db/index_builds_coordinator.h"
+#include "mongo/db/repl/repl_client_info.h"
+#include "mongo/db/repl/repl_set_config.h"
+#include "mongo/db/repl/replication_coordinator.h"
+#include "mongo/db/server_options.h"
+#include "mongo/util/assert_util.h"
+#include "mongo/util/scopeguard.h"
+
+namespace mongo {
+
+ShardLocal::ShardLocal(const ShardId& id) : Shard(id), _rsLocalClient() {
+    // Currently ShardLocal only works for config servers. If we ever start using ShardLocal on
+    // shards we'll need to consider how to handle shards.
+    invariant(serverGlobalParams.clusterRole == ClusterRole::ConfigServer);
+}
+
+const ConnectionString ShardLocal::getConnString() const {
+    return repl::ReplicationCoordinator::get(getGlobalServiceContext())
+        ->getConfig()
+        .getConnectionString();
+}
+
+std::shared_ptr<RemoteCommandTargeter> ShardLocal::getTargeter() const {
+    MONGO_UNREACHABLE;
+};
+
+const ConnectionString ShardLocal::originalConnString() const {
+    // Return the local connection string here as this method is only used for updating the
+    // ShardRegistry and we don't need a mapping from hosts in the replica set config to the shard
+    // for local shards.
+    return ConnectionString::forLocal();
+}
+
+void ShardLocal::updateReplSetMonitor(const HostAndPort& remoteHost,
+                                      const Status& remoteCommandStatus) {
+    MONGO_UNREACHABLE;
+}
+
+void ShardLocal::updateLastCommittedOpTime(LogicalTime lastCommittedOpTime) {
+    MONGO_UNREACHABLE;
+}
+
+LogicalTime ShardLocal::getLastCommittedOpTime() const {
+    MONGO_UNREACHABLE;
+}
+
+std::string ShardLocal::toString() const {
+    return getId().toString() + ":<local>";
+}
+
+bool ShardLocal::isRetriableError(ErrorCodes::Error code, RetryPolicy options) {
+    if (options == RetryPolicy::kNoRetry) {
+        return false;
+    }
+
+    if (options == RetryPolicy::kIdempotent) {
+        return code == ErrorCodes::WriteConcernFailed;
+    } else {
+        invariant(options == RetryPolicy::kNotIdempotent);
+        return false;
+    }
+}
+
+StatusWith<Shard::CommandResponse> ShardLocal::_runCommand(OperationContext* opCtx,
+                                                           const ReadPreferenceSetting& unused,
+                                                           StringData dbName,
+                                                           Milliseconds maxTimeMSOverrideUnused,
+                                                           const BSONObj& cmdObj) {
+    return _rsLocalClient.runCommandOnce(opCtx, dbName, cmdObj);
+}
+
+StatusWith<Shard::QueryResponse> ShardLocal::_runExhaustiveCursorCommand(
+    OperationContext* opCtx,
+    const ReadPreferenceSetting& readPref,
+    StringData dbName,
+    Milliseconds maxTimeMSOverride,
+    const BSONObj& cmdObj) {
+    MONGO_UNREACHABLE;
+}
+
+StatusWith<Shard::QueryResponse> ShardLocal::_exhaustiveFindOnConfig(
+    OperationContext* opCtx,
+    const ReadPreferenceSetting& readPref,
+    const repl::ReadConcernLevel& readConcernLevel,
+    const NamespaceString& nss,
+    const BSONObj& query,
+    const BSONObj& sort,
+    boost::optional<long long> limit) {
+    return _rsLocalClient.queryOnce(opCtx, readPref, readConcernLevel, nss, query, sort, limit);
+}
+
+Status ShardLocal::createIndexOnConfig(OperationContext* opCtx,
+                                       const NamespaceString& ns,
+                                       const BSONObj& keys,
+                                       bool unique) {
+    invariant(ns.db() == "config" || ns.db() == "admin");
+
+    try {
+        AutoGetOrCreateDb autoDb(opCtx, ns.db(), MODE_IX);
+        AutoGetCollection autoColl(opCtx, ns, MODE_X);
+        auto collection = autoColl.getCollection();
+        if (!collection) {
+            CollectionOptions options;
+            options.uuid = UUID::gen();
+            writeConflictRetry(opCtx, "ShardLocal::createIndexOnConfig", ns.ns(), [&] {
+                WriteUnitOfWork wunit(opCtx);
+                auto db = autoDb.getDb();
+                collection = db->createCollection(opCtx, ns, options);
+                invariant(collection,
+                          str::stream() << "Failed to create collection " << ns.ns()
+                                        << " in config database for indexes: " << keys);
+                wunit.commit();
+            });
+        }
+        auto indexCatalog = collection->getIndexCatalog();
+        IndexSpec index;
+        index.addKeys(keys);
+        index.unique(unique);
+        index.version(int(IndexDescriptor::kLatestIndexVersion));
+        auto removeIndexBuildsToo = false;
+        auto indexSpecs = indexCatalog->removeExistingIndexes(
+            opCtx,
+            uassertStatusOK(
+                collection->addCollationDefaultsToIndexSpecsForCreate(opCtx, {index.toBSON()})),
+            removeIndexBuildsToo);
+
+        if (indexSpecs.empty()) {
+            return Status::OK();
+        }
+
+        writeConflictRetry(opCtx, "ShardLocal::createIndexOnConfig", ns.ns(), [&] {
+            WriteUnitOfWork wunit(opCtx);
+            auto fromMigrate = true;
+            IndexBuildsCoordinator::get(opCtx)->createIndexesOnEmptyCollection(
+                opCtx, collection->uuid(), indexSpecs, fromMigrate);
+            wunit.commit();
+        });
+    } catch (const DBException& e) {
+        return e.toStatus();
+    }
+
+    return Status::OK();
+}
+
+void ShardLocal::runFireAndForgetCommand(OperationContext* opCtx,
+                                         const ReadPreferenceSetting& readPref,
+                                         const std::string& dbName,
+                                         const BSONObj& cmdObj) {
+    MONGO_UNREACHABLE;
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/shard_local.h b/src/mongo/db/s/shard_local.h
new file mode 100644
index 00000000000..2bce2dad081
--- /dev/null
+++ b/src/mongo/db/s/shard_local.h
@@ -0,0 +1,100 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/rs_local_client.h"
+#include "mongo/s/client/shard.h"
+
+namespace mongo {
+
+class ShardLocal : public Shard {
+    ShardLocal(const ShardLocal&) = delete;
+    ShardLocal& operator=(const ShardLocal&) = delete;
+
+public:
+    explicit ShardLocal(const ShardId& id);
+
+    ~ShardLocal() = default;
+
+    /**
+     * These functions are implemented for the Shard interface's sake. They should not be called on
+     * ShardLocal because doing so triggers invariants.
+     */
+    const ConnectionString getConnString() const override;
+    const ConnectionString originalConnString() const override;
+    std::shared_ptr<RemoteCommandTargeter> getTargeter() const override;
+    void updateReplSetMonitor(const HostAndPort& remoteHost,
+                              const Status& remoteCommandStatus) override;
+
+    std::string toString() const override;
+
+    bool isRetriableError(ErrorCodes::Error code, RetryPolicy options) final;
+
+    Status createIndexOnConfig(OperationContext* opCtx,
+                               const NamespaceString& ns,
+                               const BSONObj& keys,
+                               bool unique) override;
+
+    void updateLastCommittedOpTime(LogicalTime lastCommittedOpTime) final;
+
+    LogicalTime getLastCommittedOpTime() const final;
+
+    void runFireAndForgetCommand(OperationContext* opCtx,
+                                 const ReadPreferenceSetting& readPref,
+                                 const std::string& dbName,
+                                 const BSONObj& cmdObj) override;
+
+private:
+    StatusWith<Shard::CommandResponse> _runCommand(OperationContext* opCtx,
+                                                   const ReadPreferenceSetting& unused,
+                                                   StringData dbName,
+                                                   Milliseconds maxTimeMSOverrideUnused,
+                                                   const BSONObj& cmdObj) final;
+
+    StatusWith<Shard::QueryResponse> _runExhaustiveCursorCommand(
+        OperationContext* opCtx,
+        const ReadPreferenceSetting& readPref,
+        StringData dbName,
+        Milliseconds maxTimeMSOverride,
+        const BSONObj& cmdObj) final;
+
+    StatusWith<Shard::QueryResponse> _exhaustiveFindOnConfig(
+        OperationContext* opCtx,
+        const ReadPreferenceSetting& readPref,
+        const repl::ReadConcernLevel& readConcernLevel,
+        const NamespaceString& nss,
+        const BSONObj& query,
+        const BSONObj& sort,
+        boost::optional<long long> limit) final;
+
+    RSLocalClient _rsLocalClient;
+};
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/shard_local_test.cpp b/src/mongo/db/s/shard_local_test.cpp
new file mode 100644
index 00000000000..d7314c965cf
--- /dev/null
+++ b/src/mongo/db/s/shard_local_test.cpp
@@ -0,0 +1,273 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/client/read_preference.h"
+#include "mongo/db/catalog_raii.h"
+#include "mongo/db/client.h"
+#include "mongo/db/query/cursor_response.h"
+#include "mongo/db/query/find_and_modify_request.h"
+#include "mongo/db/repl/replication_coordinator.h"
+#include "mongo/db/repl/replication_coordinator_mock.h"
+#include "mongo/db/s/shard_local.h"
+#include "mongo/db/service_context_d_test_fixture.h"
+#include "mongo/db/write_concern_options.h"
+#include "mongo/s/client/shard_registry.h"
+
+namespace mongo {
+namespace {
+
+class ShardLocalTest : public ServiceContextMongoDTest {
+protected:
+    ServiceContext::UniqueOperationContext _opCtx;
+    std::unique_ptr<ShardLocal> _shardLocal;
+
+    /**
+     * Sets up and runs a FindAndModify command with ShardLocal's runCommand. Finds a document in
+     * namespace "nss" that matches "find" and updates the document with "set". Upsert and new are
+     * set to true in the FindAndModify request.
+     */
+    StatusWith<Shard::CommandResponse> runFindAndModifyRunCommand(NamespaceString nss,
+                                                                  BSONObj find,
+                                                                  BSONObj set);
+    /**
+     * Facilitates running a find query by supplying the redundant parameters. Finds documents in
+     * namespace "nss" that match "query" and returns "limit" (if there are that many) number of
+     * documents in "sort" order.
+     */
+    StatusWith<Shard::QueryResponse> runFindQuery(NamespaceString nss,
+                                                  BSONObj query,
+                                                  BSONObj sort,
+                                                  boost::optional<long long> limit);
+
+    /**
+     * Returns the index definitions that exist for the given collection.
+     */
+    StatusWith<std::vector<BSONObj>> getIndexes(NamespaceString nss);
+
+private:
+    void setUp() override;
+    void tearDown() override;
+};
+
+void ShardLocalTest::setUp() {
+    ServiceContextMongoDTest::setUp();
+    _opCtx = getGlobalServiceContext()->makeOperationContext(&cc());
+    serverGlobalParams.clusterRole = ClusterRole::ConfigServer;
+    _shardLocal = std::make_unique<ShardLocal>(ShardRegistry::kConfigServerShardId);
+    const repl::ReplSettings replSettings = {};
+    repl::ReplicationCoordinator::set(
+        getGlobalServiceContext(),
+        std::unique_ptr<repl::ReplicationCoordinator>(
+            new repl::ReplicationCoordinatorMock(_opCtx->getServiceContext(), replSettings)));
+    ASSERT_OK(repl::ReplicationCoordinator::get(getGlobalServiceContext())
+                  ->setFollowerMode(repl::MemberState::RS_PRIMARY));
+}
+
+void ShardLocalTest::tearDown() {
+    _opCtx.reset();
+    ServiceContextMongoDTest::tearDown();
+    repl::ReplicationCoordinator::set(getGlobalServiceContext(), nullptr);
+}
+
+StatusWith<Shard::CommandResponse> ShardLocalTest::runFindAndModifyRunCommand(NamespaceString nss,
+                                                                              BSONObj find,
+                                                                              BSONObj set) {
+    FindAndModifyRequest findAndModifyRequest = FindAndModifyRequest::makeUpdate(nss, find, set);
+    findAndModifyRequest.setUpsert(true);
+    findAndModifyRequest.setShouldReturnNew(true);
+    findAndModifyRequest.setWriteConcern(WriteConcernOptions(
+        WriteConcernOptions::kMajority, WriteConcernOptions::SyncMode::UNSET, Seconds(15)));
+
+    return _shardLocal->runCommandWithFixedRetryAttempts(
+        _opCtx.get(),
+        ReadPreferenceSetting{ReadPreference::PrimaryOnly},
+        nss.db().toString(),
+        findAndModifyRequest.toBSON({}),
+        Shard::RetryPolicy::kNoRetry);
+}
+
+StatusWith<std::vector<BSONObj>> ShardLocalTest::getIndexes(NamespaceString nss) {
+    auto response = _shardLocal->runCommandWithFixedRetryAttempts(
+        _opCtx.get(),
+        ReadPreferenceSetting{ReadPreference::PrimaryOnly},
+        nss.db().toString(),
+        BSON("listIndexes" << nss.coll().toString()),
+        Shard::RetryPolicy::kIdempotent);
+    if (!response.isOK()) {
+        return response.getStatus();
+    }
+    if (!response.getValue().commandStatus.isOK()) {
+        return response.getValue().commandStatus;
+    }
+
+    auto cursorResponse = CursorResponse::parseFromBSON(response.getValue().response);
+    if (!cursorResponse.isOK()) {
+        return cursorResponse.getStatus();
+    }
+    return cursorResponse.getValue().getBatch();
+}
+
+/**
+ * Takes a FindAndModify command's BSON response and parses it for the returned "value" field.
+ */
+BSONObj extractFindAndModifyNewObj(const BSONObj& responseObj) {
+    const auto& newDocElem = responseObj["value"];
+    ASSERT(!newDocElem.eoo());
+    ASSERT(newDocElem.isABSONObj());
+    return newDocElem.Obj();
+}
+
+StatusWith<Shard::QueryResponse> ShardLocalTest::runFindQuery(NamespaceString nss,
+                                                              BSONObj query,
+                                                              BSONObj sort,
+                                                              boost::optional<long long> limit) {
+    return _shardLocal->exhaustiveFindOnConfig(_opCtx.get(),
+                                               ReadPreferenceSetting{ReadPreference::PrimaryOnly},
+                                               repl::ReadConcernLevel::kMajorityReadConcern,
+                                               nss,
+                                               query,
+                                               sort,
+                                               limit);
+}
+
+TEST_F(ShardLocalTest, RunCommand) {
+    NamespaceString nss("admin.bar");
+    StatusWith<Shard::CommandResponse> findAndModifyResponse = runFindAndModifyRunCommand(
+        nss, BSON("fooItem" << 1), BSON("$set" << BSON("fooRandom" << 254)));
+
+    Shard::CommandResponse commandResponse = unittest::assertGet(findAndModifyResponse);
+    BSONObj newDocument = extractFindAndModifyNewObj(commandResponse.response);
+
+    ASSERT_EQUALS(1, newDocument["fooItem"].numberInt());
+    ASSERT_EQUALS(254, newDocument["fooRandom"].numberInt());
+}
+
+TEST_F(ShardLocalTest, FindOneWithoutLimit) {
+    NamespaceString nss("admin.bar");
+
+    // Set up documents to be queried.
+    StatusWith<Shard::CommandResponse> findAndModifyResponse = runFindAndModifyRunCommand(
+        nss, BSON("fooItem" << 1), BSON("$set" << BSON("fooRandom" << 254)));
+    ASSERT_OK(findAndModifyResponse.getStatus());
+    findAndModifyResponse = runFindAndModifyRunCommand(
+        nss, BSON("fooItem" << 3), BSON("$set" << BSON("fooRandom" << 452)));
+    ASSERT_OK(findAndModifyResponse.getStatus());
+
+    // Find a single document.
+    StatusWith<Shard::QueryResponse> response =
+        runFindQuery(nss, BSON("fooItem" << 3), BSONObj(), boost::none);
+    Shard::QueryResponse queryResponse = unittest::assertGet(response);
+
+    std::vector<BSONObj> docs = queryResponse.docs;
+    const unsigned long size = 1;
+    ASSERT_EQUALS(size, docs.size());
+    BSONObj foundDoc = docs[0];
+    ASSERT_EQUALS(3, foundDoc["fooItem"].numberInt());
+    ASSERT_EQUALS(452, foundDoc["fooRandom"].numberInt());
+}
+
+TEST_F(ShardLocalTest, FindManyWithLimit) {
+    NamespaceString nss("admin.bar");
+
+    // Set up documents to be queried.
+    StatusWith<Shard::CommandResponse> findAndModifyResponse = runFindAndModifyRunCommand(
+        nss, BSON("fooItem" << 1), BSON("$set" << BSON("fooRandom" << 254)));
+    ASSERT_OK(findAndModifyResponse.getStatus());
+    findAndModifyResponse = runFindAndModifyRunCommand(
+        nss, BSON("fooItem" << 2), BSON("$set" << BSON("fooRandom" << 444)));
+    ASSERT_OK(findAndModifyResponse.getStatus());
+    findAndModifyResponse = runFindAndModifyRunCommand(
+        nss, BSON("fooItem" << 3), BSON("$set" << BSON("fooRandom" << 452)));
+    ASSERT_OK(findAndModifyResponse.getStatus());
+
+    // Find 2 of 3 documents.
+    StatusWith<Shard::QueryResponse> response =
+        runFindQuery(nss, BSONObj(), BSON("fooItem" << 1), 2LL);
+    Shard::QueryResponse queryResponse = unittest::assertGet(response);
+
+    std::vector<BSONObj> docs = queryResponse.docs;
+    const unsigned long size = 2;
+    ASSERT_EQUALS(size, docs.size());
+    BSONObj firstDoc = docs[0];
+    ASSERT_EQUALS(1, firstDoc["fooItem"].numberInt());
+    ASSERT_EQUALS(254, firstDoc["fooRandom"].numberInt());
+    BSONObj secondDoc = docs[1];
+    ASSERT_EQUALS(2, secondDoc["fooItem"].numberInt());
+    ASSERT_EQUALS(444, secondDoc["fooRandom"].numberInt());
+}
+
+TEST_F(ShardLocalTest, FindNoMatchingDocumentsEmpty) {
+    NamespaceString nss("admin.bar");
+
+    // Set up a document.
+    StatusWith<Shard::CommandResponse> findAndModifyResponse = runFindAndModifyRunCommand(
+        nss, BSON("fooItem" << 1), BSON("$set" << BSON("fooRandom" << 254)));
+    ASSERT_OK(findAndModifyResponse.getStatus());
+
+    // Run a query that won't find any results.
+    StatusWith<Shard::QueryResponse> response =
+        runFindQuery(nss, BSON("fooItem" << 3), BSONObj(), boost::none);
+    Shard::QueryResponse queryResponse = unittest::assertGet(response);
+
+    std::vector<BSONObj> docs = queryResponse.docs;
+    const unsigned long size = 0;
+    ASSERT_EQUALS(size, docs.size());
+}
+
+TEST_F(ShardLocalTest, CreateIndex) {
+    NamespaceString nss("config.foo");
+
+    ASSERT_EQUALS(ErrorCodes::NamespaceNotFound, getIndexes(nss).getStatus());
+
+    Status status =
+        _shardLocal->createIndexOnConfig(_opCtx.get(), nss, BSON("a" << 1 << "b" << 1), true);
+    // Creating the index should implicitly create the collection
+    ASSERT_OK(status);
+
+    auto indexes = unittest::assertGet(getIndexes(nss));
+    // There should be the index we just added as well as the _id index
+    ASSERT_EQ(2U, indexes.size());
+
+    // Making an identical index should be a no-op.
+    status = _shardLocal->createIndexOnConfig(_opCtx.get(), nss, BSON("a" << 1 << "b" << 1), true);
+    ASSERT_OK(status);
+    indexes = unittest::assertGet(getIndexes(nss));
+    ASSERT_EQ(2U, indexes.size());
+
+    // Trying to make the same index as non-unique should fail.
+    status = _shardLocal->createIndexOnConfig(_opCtx.get(), nss, BSON("a" << 1 << "b" << 1), false);
+    ASSERT_EQUALS(ErrorCodes::IndexOptionsConflict, status);
+    indexes = unittest::assertGet(getIndexes(nss));
+    ASSERT_EQ(2U, indexes.size());
+}
+
+}  // namespace
+}  // namespace mongo
diff --git a/src/mongo/db/s/shard_metadata_util_test.cpp b/src/mongo/db/s/shard_metadata_util_test.cpp
index 771dbab13ec..0b963169f8d 100644
--- a/src/mongo/db/s/shard_metadata_util_test.cpp
+++ b/src/mongo/db/s/shard_metadata_util_test.cpp
@@ -35,11 +35,10 @@
 #include "mongo/client/remote_command_targeter_mock.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/dbdirectclient.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/rpc/get_status_from_command_result.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/catalog/type_shard_collection.h"
-#include "mongo/s/shard_server_test_fixture.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/shard_server_catalog_cache_loader_test.cpp b/src/mongo/db/s/shard_server_catalog_cache_loader_test.cpp
index 902b09c3a64..5cfc7ce4124 100644
--- a/src/mongo/db/s/shard_server_catalog_cache_loader_test.cpp
+++ b/src/mongo/db/s/shard_server_catalog_cache_loader_test.cpp
@@ -29,13 +29,11 @@
 
 #include "mongo/platform/basic.h"
 
-#include "mongo/db/s/shard_server_catalog_cache_loader.h"
-
 #include "mongo/db/s/catalog_cache_loader_mock.h"
+#include "mongo/db/s/shard_server_catalog_cache_loader.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/catalog/type_collection.h"
-#include "mongo/s/shard_server_test_fixture.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/shard_server_test_fixture.cpp b/src/mongo/db/s/shard_server_test_fixture.cpp
new file mode 100644
index 00000000000..b916c674792
--- /dev/null
+++ b/src/mongo/db/s/shard_server_test_fixture.cpp
@@ -0,0 +1,102 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/s/shard_server_test_fixture.h"
+
+#include "mongo/client/remote_command_targeter_mock.h"
+#include "mongo/db/commands.h"
+#include "mongo/db/repl/replication_coordinator_mock.h"
+#include "mongo/db/s/shard_server_catalog_cache_loader.h"
+#include "mongo/db/s/sharding_state.h"
+#include "mongo/s/catalog/dist_lock_catalog_mock.h"
+#include "mongo/s/catalog/dist_lock_manager_mock.h"
+#include "mongo/s/catalog/sharding_catalog_client_impl.h"
+#include "mongo/s/catalog_cache.h"
+#include "mongo/s/config_server_catalog_cache_loader.h"
+
+namespace mongo {
+
+const HostAndPort ShardServerTestFixture::kConfigHostAndPort("dummy", 123);
+
+ShardServerTestFixture::ShardServerTestFixture() = default;
+
+ShardServerTestFixture::~ShardServerTestFixture() = default;
+
+std::shared_ptr<RemoteCommandTargeterMock> ShardServerTestFixture::configTargeterMock() {
+    return RemoteCommandTargeterMock::get(shardRegistry()->getConfigShard()->getTargeter());
+}
+
+void ShardServerTestFixture::setUp() {
+    ShardingMongodTestFixture::setUp();
+
+    replicationCoordinator()->alwaysAllowWrites(true);
+
+    // Initialize sharding components as a shard server.
+    serverGlobalParams.clusterRole = ClusterRole::ShardServer;
+
+    _clusterId = OID::gen();
+    ShardingState::get(getServiceContext())->setInitialized(_myShardName, _clusterId);
+
+    CatalogCacheLoader::set(getServiceContext(),
+                            std::make_unique<ShardServerCatalogCacheLoader>(
+                                std::make_unique<ConfigServerCatalogCacheLoader>()));
+
+    uassertStatusOK(
+        initializeGlobalShardingStateForMongodForTest(ConnectionString(kConfigHostAndPort)));
+
+    // Set the findHost() return value on the mock targeter so that later calls to the
+    // config targeter's findHost() return the appropriate value.
+    configTargeterMock()->setFindHostReturnValue(kConfigHostAndPort);
+}
+
+void ShardServerTestFixture::tearDown() {
+    CatalogCacheLoader::clearForTests(getServiceContext());
+
+    ShardingMongodTestFixture::tearDown();
+}
+
+std::unique_ptr<DistLockCatalog> ShardServerTestFixture::makeDistLockCatalog() {
+    return std::make_unique<DistLockCatalogMock>();
+}
+
+std::unique_ptr<DistLockManager> ShardServerTestFixture::makeDistLockManager(
+    std::unique_ptr<DistLockCatalog> distLockCatalog) {
+    invariant(distLockCatalog);
+    return std::make_unique<DistLockManagerMock>(std::move(distLockCatalog));
+}
+
+std::unique_ptr<ShardingCatalogClient> ShardServerTestFixture::makeShardingCatalogClient(
+    std::unique_ptr<DistLockManager> distLockManager) {
+    invariant(distLockManager);
+    return std::make_unique<ShardingCatalogClientImpl>(std::move(distLockManager));
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/shard_server_test_fixture.h b/src/mongo/db/s/shard_server_test_fixture.h
new file mode 100644
index 00000000000..deee682e174
--- /dev/null
+++ b/src/mongo/db/s/shard_server_test_fixture.h
@@ -0,0 +1,83 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/s/sharding_mongod_test_fixture.h"
+
+namespace mongo {
+
+/**
+ * Test fixture for shard components, as opposed to config or mongos components. Provides a mock
+ * network and ephemeral storage engine via ShardingMongodTestFixture. Additionally sets up mock
+ * dist lock catalog and manager with a real catalog client.
+ */
+class ShardServerTestFixture : public ShardingMongodTestFixture {
+protected:
+    ShardServerTestFixture();
+    ~ShardServerTestFixture();
+
+    void setUp() override;
+    void tearDown() override;
+
+    /**
+     * Returns the mock targeter for the config server. Useful to use like so,
+     *
+     *     configTargeterMock()->setFindHostReturnValue(HostAndPort);
+     *     configTargeterMock()->setFindHostReturnValue({ErrorCodes::InternalError, "can't target"})
+     *
+     * Remote calls always need to resolve a host with RemoteCommandTargeterMock::findHost, so it
+     * must be set.
+     */
+    std::shared_ptr<RemoteCommandTargeterMock> configTargeterMock();
+
+    /**
+     * Creates a DistLockCatalogMock.
+     */
+    std::unique_ptr<DistLockCatalog> makeDistLockCatalog() override;
+
+    /**
+     * Creates a DistLockManagerMock.
+     */
+    std::unique_ptr<DistLockManager> makeDistLockManager(
+        std::unique_ptr<DistLockCatalog> distLockCatalog) override;
+
+    /**
+     * Creates a real ShardingCatalogClient.
+     */
+    std::unique_ptr<ShardingCatalogClient> makeShardingCatalogClient(
+        std::unique_ptr<DistLockManager> distLockManager) override;
+
+    static const HostAndPort kConfigHostAndPort;
+
+    const ShardId _myShardName{"myShardName"};
+    OID _clusterId;
+};
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/sharding_initialization_mongod.cpp b/src/mongo/db/s/sharding_initialization_mongod.cpp
index accb9c65406..0ab2d96fab7 100644
--- a/src/mongo/db/s/sharding_initialization_mongod.cpp
+++ b/src/mongo/db/s/sharding_initialization_mongod.cpp
@@ -50,6 +50,7 @@
 #include "mongo/db/s/chunk_splitter.h"
 #include "mongo/db/s/periodic_balancer_config_refresher.h"
 #include "mongo/db/s/read_only_catalog_cache_loader.h"
+#include "mongo/db/s/shard_local.h"
 #include "mongo/db/s/shard_server_catalog_cache_loader.h"
 #include "mongo/db/s/sharding_config_optime_gossip.h"
 #include "mongo/db/s/transaction_coordinator_service.h"
@@ -59,7 +60,6 @@
 #include "mongo/rpc/metadata/egress_metadata_hook_list.h"
 #include "mongo/s/catalog_cache.h"
 #include "mongo/s/client/shard_factory.h"
-#include "mongo/s/client/shard_local.h"
 #include "mongo/s/client/shard_remote.h"
 #include "mongo/s/client/sharding_connection_hook.h"
 #include "mongo/s/config_server_catalog_cache_loader.h"
diff --git a/src/mongo/db/s/sharding_initialization_mongod_test.cpp b/src/mongo/db/s/sharding_initialization_mongod_test.cpp
index 6af6ff00399..a724a245f84 100644
--- a/src/mongo/db/s/sharding_initialization_mongod_test.cpp
+++ b/src/mongo/db/s/sharding_initialization_mongod_test.cpp
@@ -40,6 +40,7 @@
 #include "mongo/db/s/op_observer_sharding_impl.h"
 #include "mongo/db/s/shard_server_catalog_cache_loader.h"
 #include "mongo/db/s/shard_server_op_observer.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/sharding_initialization_mongod.h"
 #include "mongo/db/s/type_shard_identity.h"
 #include "mongo/db/server_options.h"
@@ -47,7 +48,6 @@
 #include "mongo/s/catalog/sharding_catalog_client_impl.h"
 #include "mongo/s/client/shard_registry.h"
 #include "mongo/s/config_server_catalog_cache_loader.h"
-#include "mongo/s/shard_server_test_fixture.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/sharding_initialization_op_observer_test.cpp b/src/mongo/db/s/sharding_initialization_op_observer_test.cpp
index 6cd2ccd2605..563a6325454 100644
--- a/src/mongo/db/s/sharding_initialization_op_observer_test.cpp
+++ b/src/mongo/db/s/sharding_initialization_op_observer_test.cpp
@@ -40,12 +40,12 @@
 #include "mongo/db/s/shard_server_catalog_cache_loader.h"
 #include "mongo/db/s/shard_server_op_observer.h"
 #include "mongo/db/s/sharding_initialization_mongod.h"
+#include "mongo/db/s/sharding_mongod_test_fixture.h"
 #include "mongo/db/s/type_shard_identity.h"
 #include "mongo/db/server_options.h"
 #include "mongo/s/catalog/dist_lock_manager_mock.h"
 #include "mongo/s/client/shard_registry.h"
 #include "mongo/s/config_server_catalog_cache_loader.h"
-#include "mongo/s/sharding_mongod_test_fixture.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/sharding_logging_test.cpp b/src/mongo/db/s/sharding_logging_test.cpp
index a014091b49b..a5622798baa 100644
--- a/src/mongo/db/s/sharding_logging_test.cpp
+++ b/src/mongo/db/s/sharding_logging_test.cpp
@@ -33,14 +33,12 @@
 
 #include <vector>
 
-#include "mongo/client/remote_command_targeter_mock.h"
 #include "mongo/db/commands.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/sharding_logging.h"
-#include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/task_executor.h"
 #include "mongo/s/catalog/sharding_catalog_client.h"
 #include "mongo/s/client/shard_registry.h"
-#include "mongo/s/sharding_router_test_fixture.h"
 #include "mongo/stdx/chrono.h"
 #include "mongo/stdx/future.h"
 #include "mongo/util/str.h"
@@ -49,34 +47,24 @@
 namespace mongo {
 namespace {
 
-using executor::NetworkInterfaceMock;
-using executor::TaskExecutor;
-using stdx::async;
 using unittest::assertGet;
 
-const HostAndPort configHost{"TestHost1"};
-
-class InfoLoggingTest : public ShardingTestFixture {
+class InfoLoggingTest : public ShardServerTestFixture {
 public:
     enum CollType { ActionLog, ChangeLog };
 
     InfoLoggingTest(CollType configCollType, int cappedSize)
         : _configCollType(configCollType), _cappedSize(cappedSize) {}
 
-    void setUp() override {
-        ShardingTestFixture::setUp();
-
-        configTargeter()->setFindHostReturnValue(configHost);
-    }
-
 protected:
     void noRetryAfterSuccessfulCreate() {
         auto future = launchAsync([this] {
             log("moved a chunk", "foo.bar", BSON("min" << 3 << "max" << 4)).transitional_ignore();
         });
 
-        expectConfigCollectionCreate(configHost, getConfigCollName(), _cappedSize, BSON("ok" << 1));
-        expectConfigCollectionInsert(configHost,
+        expectConfigCollectionCreate(
+            kConfigHostAndPort, getConfigCollName(), _cappedSize, BSON("ok" << 1));
+        expectConfigCollectionInsert(kConfigHostAndPort,
                                      getConfigCollName(),
                                      network()->now(),
                                      "moved a chunk",
@@ -92,7 +80,7 @@ protected:
                 .transitional_ignore();
         });
 
-        expectConfigCollectionInsert(configHost,
+        expectConfigCollectionInsert(kConfigHostAndPort,
                                      getConfigCollName(),
                                      network()->now(),
                                      "moved a second chunk",
@@ -112,8 +100,8 @@ protected:
         CommandHelpers::appendCommandStatusNoThrow(
             createResponseBuilder, Status(ErrorCodes::NamespaceExists, "coll already exists"));
         expectConfigCollectionCreate(
-            configHost, getConfigCollName(), _cappedSize, createResponseBuilder.obj());
-        expectConfigCollectionInsert(configHost,
+            kConfigHostAndPort, getConfigCollName(), _cappedSize, createResponseBuilder.obj());
+        expectConfigCollectionInsert(kConfigHostAndPort,
                                      getConfigCollName(),
                                      network()->now(),
                                      "moved a chunk",
@@ -129,7 +117,7 @@ protected:
                 .transitional_ignore();
         });
 
-        expectConfigCollectionInsert(configHost,
+        expectConfigCollectionInsert(kConfigHostAndPort,
                                      getConfigCollName(),
                                      network()->now(),
                                      "moved a second chunk",
@@ -149,7 +137,7 @@ protected:
         CommandHelpers::appendCommandStatusNoThrow(
             createResponseBuilder, Status(ErrorCodes::Interrupted, "operation interrupted"));
         expectConfigCollectionCreate(
-            configHost, getConfigCollName(), _cappedSize, createResponseBuilder.obj());
+            kConfigHostAndPort, getConfigCollName(), _cappedSize, createResponseBuilder.obj());
 
         // Now wait for the logAction call to return
         future.default_timed_get();
@@ -160,8 +148,9 @@ protected:
                 .transitional_ignore();
         });
 
-        expectConfigCollectionCreate(configHost, getConfigCollName(), _cappedSize, BSON("ok" << 1));
-        expectConfigCollectionInsert(configHost,
+        expectConfigCollectionCreate(
+            kConfigHostAndPort, getConfigCollName(), _cappedSize, BSON("ok" << 1));
+        expectConfigCollectionInsert(kConfigHostAndPort,
                                      getConfigCollName(),
                                      network()->now(),
                                      "moved a second chunk",
diff --git a/src/mongo/db/s/sharding_mongod_test_fixture.cpp b/src/mongo/db/s/sharding_mongod_test_fixture.cpp
new file mode 100644
index 00000000000..932b2ff5424
--- /dev/null
+++ b/src/mongo/db/s/sharding_mongod_test_fixture.cpp
@@ -0,0 +1,337 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/s/sharding_mongod_test_fixture.h"
+
+#include <algorithm>
+#include <memory>
+#include <vector>
+
+#include "mongo/base/checked_cast.h"
+#include "mongo/client/replica_set_monitor.h"
+#include "mongo/db/catalog_raii.h"
+#include "mongo/db/client.h"
+#include "mongo/db/commands.h"
+#include "mongo/db/namespace_string.h"
+#include "mongo/db/op_observer_registry.h"
+#include "mongo/db/query/cursor_response.h"
+#include "mongo/db/query/query_request.h"
+#include "mongo/db/repl/drop_pending_collection_reaper.h"
+#include "mongo/db/repl/oplog.h"
+#include "mongo/db/repl/read_concern_args.h"
+#include "mongo/db/repl/repl_settings.h"
+#include "mongo/db/repl/replication_consistency_markers_mock.h"
+#include "mongo/db/repl/replication_process.h"
+#include "mongo/db/repl/replication_recovery_mock.h"
+#include "mongo/db/repl/storage_interface_mock.h"
+#include "mongo/db/s/collection_sharding_state_factory_shard.h"
+#include "mongo/db/s/config_server_op_observer.h"
+#include "mongo/db/s/op_observer_sharding_impl.h"
+#include "mongo/db/s/shard_local.h"
+#include "mongo/db/s/shard_server_op_observer.h"
+#include "mongo/executor/task_executor_pool.h"
+#include "mongo/executor/thread_pool_task_executor_test_fixture.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
+#include "mongo/s/balancer_configuration.h"
+#include "mongo/s/catalog/dist_lock_catalog.h"
+#include "mongo/s/catalog/dist_lock_manager.h"
+#include "mongo/s/catalog/sharding_catalog_client.h"
+#include "mongo/s/catalog/type_collection.h"
+#include "mongo/s/catalog/type_shard.h"
+#include "mongo/s/catalog_cache.h"
+#include "mongo/s/catalog_cache_loader.h"
+#include "mongo/s/client/shard_factory.h"
+#include "mongo/s/client/shard_registry.h"
+#include "mongo/s/client/shard_remote.h"
+#include "mongo/s/grid.h"
+#include "mongo/s/query/cluster_cursor_manager.h"
+#include "mongo/s/request_types/set_shard_version_request.h"
+#include "mongo/util/clock_source_mock.h"
+#include "mongo/util/tick_source_mock.h"
+
+namespace mongo {
+
+using executor::NetworkInterfaceMock;
+using executor::NetworkTestEnv;
+using executor::RemoteCommandRequest;
+using executor::RemoteCommandResponse;
+using repl::ReplicationCoordinator;
+using repl::ReplicationCoordinatorMock;
+using repl::ReplSettings;
+using unittest::assertGet;
+
+ShardingMongodTestFixture::ShardingMongodTestFixture() {
+    const auto service = getServiceContext();
+
+    // Set up this node as shard node, which is part of a replica set
+
+    repl::ReplSettings replSettings;
+    replSettings.setOplogSizeBytes(512'000);
+    replSettings.setReplSetString(ConnectionString::forReplicaSet(_setName, _servers).toString());
+    auto replCoordPtr = makeReplicationCoordinator(replSettings);
+    _replCoord = replCoordPtr.get();
+
+    BSONArrayBuilder serversBob;
+    for (size_t i = 0; i < _servers.size(); ++i) {
+        serversBob.append(BSON("host" << _servers[i].toString() << "_id" << static_cast<int>(i)));
+    }
+
+    auto replSetConfig =
+        repl::ReplSetConfig::parse(BSON("_id" << _setName << "protocolVersion" << 1 << "version"
+                                              << 3 << "members" << serversBob.arr()));
+    replCoordPtr->setGetConfigReturnValue(replSetConfig);
+
+    repl::ReplicationCoordinator::set(service, std::move(replCoordPtr));
+
+    auto storagePtr = std::make_unique<repl::StorageInterfaceMock>();
+
+    repl::DropPendingCollectionReaper::set(
+        service, std::make_unique<repl::DropPendingCollectionReaper>(storagePtr.get()));
+
+    repl::ReplicationProcess::set(service,
+                                  std::make_unique<repl::ReplicationProcess>(
+                                      storagePtr.get(),
+                                      std::make_unique<repl::ReplicationConsistencyMarkersMock>(),
+                                      std::make_unique<repl::ReplicationRecoveryMock>()));
+
+    ASSERT_OK(repl::ReplicationProcess::get(operationContext())
+                  ->initializeRollbackID(operationContext()));
+
+    repl::StorageInterface::set(service, std::move(storagePtr));
+
+    auto opObserver = checked_cast<OpObserverRegistry*>(service->getOpObserver());
+    opObserver->addObserver(std::make_unique<OpObserverShardingImpl>());
+    opObserver->addObserver(std::make_unique<ConfigServerOpObserver>());
+    opObserver->addObserver(std::make_unique<ShardServerOpObserver>());
+
+    repl::setOplogCollectionName(service);
+    repl::createOplog(operationContext());
+
+    // Set the highest FCV because otherwise it defaults to the lower FCV. This way we default to
+    // testing this release's code, not backwards compatibility code.
+    serverGlobalParams.featureCompatibility.setVersion(
+        ServerGlobalParams::FeatureCompatibility::Version::kFullyUpgradedTo46);
+}
+
+ShardingMongodTestFixture::~ShardingMongodTestFixture() = default;
+
+std::unique_ptr<ReplicationCoordinatorMock> ShardingMongodTestFixture::makeReplicationCoordinator(
+    ReplSettings replSettings) {
+    auto coordinator =
+        std::make_unique<repl::ReplicationCoordinatorMock>(getServiceContext(), replSettings);
+    ASSERT_OK(coordinator->setFollowerMode(repl::MemberState::RS_PRIMARY));
+    return coordinator;
+}
+
+std::unique_ptr<executor::TaskExecutorPool> ShardingMongodTestFixture::_makeTaskExecutorPool() {
+    // Set up a NetworkInterfaceMock. Note, unlike NetworkInterfaceASIO, which has its own pool of
+    // threads, tasks in the NetworkInterfaceMock must be carried out synchronously by the (single)
+    // thread the unit test is running on.
+    auto netForFixedTaskExecutor = std::make_unique<executor::NetworkInterfaceMock>();
+    _mockNetwork = netForFixedTaskExecutor.get();
+
+    // Set up a ThreadPoolTaskExecutor. Note, for local tasks this TaskExecutor uses a
+    // ThreadPoolMock, and for remote tasks it uses the NetworkInterfaceMock created above. However,
+    // note that the ThreadPoolMock uses the NetworkInterfaceMock's threads to run tasks, which is
+    // again just the (single) thread the unit test is running on. Therefore, all tasks, local and
+    // remote, must be carried out synchronously by the test thread.
+    auto fixedTaskExecutor = makeSharedThreadPoolTestExecutor(std::move(netForFixedTaskExecutor));
+    _networkTestEnv = std::make_unique<NetworkTestEnv>(fixedTaskExecutor.get(), _mockNetwork);
+
+    // Set up (one) TaskExecutor for the set of arbitrary TaskExecutors.
+    std::vector<std::shared_ptr<executor::TaskExecutor>> arbitraryExecutorsForExecutorPool;
+    arbitraryExecutorsForExecutorPool.emplace_back(
+        makeSharedThreadPoolTestExecutor(std::make_unique<executor::NetworkInterfaceMock>()));
+
+    // Set up the TaskExecutorPool with the fixed TaskExecutor and set of arbitrary TaskExecutors.
+    auto executorPool = std::make_unique<executor::TaskExecutorPool>();
+    executorPool->addExecutors(std::move(arbitraryExecutorsForExecutorPool),
+                               std::move(fixedTaskExecutor));
+
+    return executorPool;
+}
+
+std::unique_ptr<ShardRegistry> ShardingMongodTestFixture::makeShardRegistry(
+    ConnectionString configConnStr) {
+    auto targeterFactory(std::make_unique<RemoteCommandTargeterFactoryMock>());
+    auto targeterFactoryPtr = targeterFactory.get();
+    _targeterFactory = targeterFactoryPtr;
+
+    ShardFactory::BuilderCallable setBuilder = [targeterFactoryPtr](
+                                                   const ShardId& shardId,
+                                                   const ConnectionString& connStr) {
+        return std::make_unique<ShardRemote>(shardId, connStr, targeterFactoryPtr->create(connStr));
+    };
+
+    ShardFactory::BuilderCallable masterBuilder = [targeterFactoryPtr](
+                                                      const ShardId& shardId,
+                                                      const ConnectionString& connStr) {
+        return std::make_unique<ShardRemote>(shardId, connStr, targeterFactoryPtr->create(connStr));
+    };
+
+    ShardFactory::BuildersMap buildersMap{{ConnectionString::SET, std::move(setBuilder)},
+                                          {ConnectionString::MASTER, std::move(masterBuilder)}};
+
+    // Only config servers use ShardLocal for now.
+    if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
+        ShardFactory::BuilderCallable localBuilder = [](const ShardId& shardId,
+                                                        const ConnectionString& connStr) {
+            return std::make_unique<ShardLocal>(shardId);
+        };
+        buildersMap.insert(
+            std::pair<ConnectionString::ConnectionType, ShardFactory::BuilderCallable>(
+                ConnectionString::LOCAL, std::move(localBuilder)));
+    }
+
+    auto shardFactory =
+        std::make_unique<ShardFactory>(std::move(buildersMap), std::move(targeterFactory));
+
+    return std::make_unique<ShardRegistry>(std::move(shardFactory), configConnStr);
+}
+
+std::unique_ptr<DistLockCatalog> ShardingMongodTestFixture::makeDistLockCatalog() {
+    return nullptr;
+}
+
+std::unique_ptr<DistLockManager> ShardingMongodTestFixture::makeDistLockManager(
+    std::unique_ptr<DistLockCatalog> distLockCatalog) {
+    return nullptr;
+}
+
+std::unique_ptr<ClusterCursorManager> ShardingMongodTestFixture::makeClusterCursorManager() {
+    return nullptr;
+}
+
+std::unique_ptr<BalancerConfiguration> ShardingMongodTestFixture::makeBalancerConfiguration() {
+    return std::make_unique<BalancerConfiguration>();
+}
+
+Status ShardingMongodTestFixture::initializeGlobalShardingStateForMongodForTest(
+    const ConnectionString& configConnStr) {
+    invariant(serverGlobalParams.clusterRole == ClusterRole::ShardServer ||
+              serverGlobalParams.clusterRole == ClusterRole::ConfigServer);
+
+    // Create and initialize each sharding component individually before moving them to the Grid
+    // in order to control the order of initialization, since some components depend on others.
+
+    auto executorPoolPtr = _makeTaskExecutorPool();
+    if (executorPoolPtr) {
+        executorPoolPtr->startup();
+    }
+
+    auto distLockCatalogPtr = makeDistLockCatalog();
+    _distLockCatalog = distLockCatalogPtr.get();
+
+    auto distLockManagerPtr = makeDistLockManager(std::move(distLockCatalogPtr));
+    _distLockManager = distLockManagerPtr.get();
+
+    auto const grid = Grid::get(operationContext());
+    grid->init(makeShardingCatalogClient(std::move(distLockManagerPtr)),
+               std::make_unique<CatalogCache>(CatalogCacheLoader::get(getServiceContext())),
+               makeShardRegistry(configConnStr),
+               makeClusterCursorManager(),
+               makeBalancerConfiguration(),
+               std::move(executorPoolPtr),
+               _mockNetwork);
+
+    // NOTE: ShardRegistry::startup() is not called because it starts a task executor with a
+    // self-rescheduling task to reload the ShardRegistry over the network.
+    // grid->shardRegistry()->startup();
+
+    if (grid->catalogClient()) {
+        grid->catalogClient()->startup();
+    }
+
+    return Status::OK();
+}
+
+void ShardingMongodTestFixture::tearDown() {
+    ReplicaSetMonitor::cleanup();
+
+    if (Grid::get(operationContext())->getExecutorPool() && !_executorPoolShutDown) {
+        Grid::get(operationContext())->getExecutorPool()->shutdownAndJoin();
+    }
+
+    if (Grid::get(operationContext())->catalogClient()) {
+        Grid::get(operationContext())->catalogClient()->shutDown(operationContext());
+    }
+
+    if (Grid::get(operationContext())->shardRegistry()) {
+        Grid::get(operationContext())->shardRegistry()->shutdown();
+    }
+
+    Grid::get(operationContext())->clearForUnitTests();
+
+    ServiceContextMongoDTest::tearDown();
+}
+
+ShardingCatalogClient* ShardingMongodTestFixture::catalogClient() const {
+    invariant(Grid::get(operationContext())->catalogClient());
+    return Grid::get(operationContext())->catalogClient();
+}
+
+CatalogCache* ShardingMongodTestFixture::catalogCache() const {
+    invariant(Grid::get(operationContext())->catalogCache());
+    return Grid::get(operationContext())->catalogCache();
+}
+
+ShardRegistry* ShardingMongodTestFixture::shardRegistry() const {
+    invariant(Grid::get(operationContext())->shardRegistry());
+    return Grid::get(operationContext())->shardRegistry();
+}
+
+ClusterCursorManager* ShardingMongodTestFixture::clusterCursorManager() const {
+    invariant(Grid::get(operationContext())->getCursorManager());
+    return Grid::get(operationContext())->getCursorManager();
+}
+
+executor::TaskExecutorPool* ShardingMongodTestFixture::executorPool() const {
+    invariant(Grid::get(operationContext())->getExecutorPool());
+    return Grid::get(operationContext())->getExecutorPool();
+}
+
+void ShardingMongodTestFixture::shutdownExecutorPool() {
+    invariant(!_executorPoolShutDown);
+    executorPool()->shutdownAndJoin();
+    _executorPoolShutDown = true;
+}
+
+std::shared_ptr<executor::TaskExecutor> ShardingMongodTestFixture::executor() const {
+    invariant(Grid::get(operationContext())->getExecutorPool());
+    return Grid::get(operationContext())->getExecutorPool()->getFixedExecutor();
+}
+
+repl::ReplicationCoordinatorMock* ShardingMongodTestFixture::replicationCoordinator() const {
+    invariant(_replCoord);
+    return _replCoord;
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/sharding_mongod_test_fixture.h b/src/mongo/db/s/sharding_mongod_test_fixture.h
new file mode 100644
index 00000000000..6495ee3377a
--- /dev/null
+++ b/src/mongo/db/s/sharding_mongod_test_fixture.h
@@ -0,0 +1,152 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/repl/replication_coordinator_mock.h"
+#include "mongo/db/service_context_d_test_fixture.h"
+#include "mongo/s/sharding_test_fixture_common.h"
+
+namespace mongo {
+
+class CatalogCacheLoader;
+
+namespace repl {
+class ReplSettings;
+}  // namespace repl
+
+/**
+ * Sets up this fixture as a mongod with a storage engine, OpObserver, and as a member of a replica
+ * set.
+ *
+ * Additionally, provides an interface for initializing sharding components, mimicking the process
+ * by which a real config or shard server does sharding initialization. Provides a set of default
+ * components (including a NetworkInterface/TaskExecutor subsystem backed by the NetworkTestEnv),
+ * but allows subclasses to replace any component with its real implementation, a mock, or nullptr.
+ */
+class ShardingMongodTestFixture : public ServiceContextMongoDTest,
+                                  public ShardingTestFixtureCommon {
+protected:
+    ShardingMongodTestFixture();
+    ~ShardingMongodTestFixture();
+
+    void tearDown() override;
+
+    /**
+     * Initializes sharding components according to the cluster role in
+     * serverGlobalParams.clusterRole and puts the components on the Grid, mimicking the
+     * initialization done by an actual config or shard mongod server.
+     *
+     * It is illegal to call this if serverGlobalParams.clusterRole is not ClusterRole::ShardServer
+     * or ClusterRole::ConfigServer.
+     */
+    Status initializeGlobalShardingStateForMongodForTest(const ConnectionString& configConnStr);
+
+    // Syntactic sugar for getting sharding components off the Grid, if they have been initialized.
+
+    ShardingCatalogClient* catalogClient() const;
+    CatalogCache* catalogCache() const;
+    ShardRegistry* shardRegistry() const;
+    std::shared_ptr<executor::TaskExecutor> executor() const;
+    ClusterCursorManager* clusterCursorManager() const;
+    executor::TaskExecutorPool* executorPool() const;
+
+    /**
+     * Shuts down the TaskExecutorPool and remembers that it has been shut down, so that it is not
+     * shut down again on tearDown.
+     *
+     * Not safe to call from multiple threads.
+     */
+    void shutdownExecutorPool();
+
+    repl::ReplicationCoordinatorMock* replicationCoordinator() const;
+
+    // Methods for creating and returning sharding components. Some of these methods have been
+    // implemented to return the real implementation of the component as the default, while others
+    // return a mock or nullptr. Subclasses can override any of these methods to create and
+    // initialize a real implementation, a mock, or nullptr, as needed.
+
+    // Warning: If a component takes ownership of another component for which a real or mock is
+    // being used, the component must also be real or mock implementation, so that it can actually
+    // take the ownership.
+
+    /**
+     * Base class returns ReplicationCoordinatorMock.
+     */
+    virtual std::unique_ptr<repl::ReplicationCoordinatorMock> makeReplicationCoordinator(
+        repl::ReplSettings replSettings);
+
+    /**
+     * Base class returns a real implementation of ShardRegistry.
+     */
+    virtual std::unique_ptr<ShardRegistry> makeShardRegistry(ConnectionString configConnStr);
+
+    /**
+     * Base class returns nullptr.
+     */
+    virtual std::unique_ptr<DistLockCatalog> makeDistLockCatalog();
+
+    /**
+     * Base class returns nullptr.
+     *
+     * Note: DistLockManager takes ownership of the DistLockCatalog, so if DistLockCatalog is not
+     * nullptr, a real or mock DistLockManager must be supplied.
+     */
+    virtual std::unique_ptr<DistLockManager> makeDistLockManager(
+        std::unique_ptr<DistLockCatalog> distLockCatalog);
+
+    /**
+     * Base class returns nullptr.
+     */
+    virtual std::unique_ptr<ClusterCursorManager> makeClusterCursorManager();
+
+    /**
+     * Base class returns nullptr.
+     */
+    virtual std::unique_ptr<BalancerConfiguration> makeBalancerConfiguration();
+
+private:
+    /**
+     * Base class returns a TaskExecutorPool with a fixed TaskExecutor and a set of arbitrary
+     * executors containing one TaskExecutor, each backed by a NetworkInterfaceMock/ThreadPoolMock
+     * subsytem.
+     */
+    std::unique_ptr<executor::TaskExecutorPool> _makeTaskExecutorPool();
+
+    const std::string _setName = "mySet";
+    const std::vector<HostAndPort> _servers{
+        HostAndPort("node1:12345"), HostAndPort("node2:12345"), HostAndPort("node3:12345")};
+
+    repl::ReplicationCoordinatorMock* _replCoord = nullptr;
+
+    // Records if a component has been shut down, so that it is only shut down once.
+    bool _executorPoolShutDown = false;
+};
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/split_chunk_test.cpp b/src/mongo/db/s/split_chunk_test.cpp
index cfdc61f2b61..532ff9dab55 100644
--- a/src/mongo/db/s/split_chunk_test.cpp
+++ b/src/mongo/db/s/split_chunk_test.cpp
@@ -33,12 +33,11 @@
 
 #include <boost/optional.hpp>
 
-#include "mongo/client/remote_command_targeter_mock.h"
 #include "mongo/db/json.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/sharding_initialization_mongod.h"
 #include "mongo/db/s/split_chunk.h"
 #include "mongo/db/server_options.h"
-#include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/remote_command_request.h"
 #include "mongo/executor/remote_command_response.h"
 #include "mongo/executor/task_executor.h"
@@ -51,10 +50,8 @@
 #include "mongo/s/catalog_cache_loader.h"
 #include "mongo/s/client/shard_registry.h"
 #include "mongo/s/grid.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/s/write_ops/batched_command_request.h"
 #include "mongo/s/write_ops/batched_command_response.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/split_vector_test.cpp b/src/mongo/db/s/split_vector_test.cpp
index 7350527d8b3..807bb35d4aa 100644
--- a/src/mongo/db/s/split_vector_test.cpp
+++ b/src/mongo/db/s/split_vector_test.cpp
@@ -34,9 +34,8 @@
 #include "mongo/db/db_raii.h"
 #include "mongo/db/dbdirectclient.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/split_vector.h"
-#include "mongo/s/shard_server_test_fixture.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 namespace {
diff --git a/src/mongo/db/s/transaction_coordinator_futures_util_test.cpp b/src/mongo/db/s/transaction_coordinator_futures_util_test.cpp
index fb145b325aa..e46ab94599f 100644
--- a/src/mongo/db/s/transaction_coordinator_futures_util_test.cpp
+++ b/src/mongo/db/s/transaction_coordinator_futures_util_test.cpp
@@ -30,12 +30,11 @@
 #include "mongo/platform/basic.h"
 
 #include "mongo/client/remote_command_targeter_mock.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/transaction_coordinator_futures_util.h"
 #include "mongo/s/catalog/sharding_catalog_client_mock.h"
 #include "mongo/s/catalog/type_shard.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/unittest/barrier.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 namespace txn {
diff --git a/src/mongo/db/s/transaction_coordinator_test_fixture.h b/src/mongo/db/s/transaction_coordinator_test_fixture.h
index 03763d3e2a1..37232f0d340 100644
--- a/src/mongo/db/s/transaction_coordinator_test_fixture.h
+++ b/src/mongo/db/s/transaction_coordinator_test_fixture.h
@@ -33,9 +33,9 @@
 #include <vector>
 
 #include "mongo/base/status.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/s/transaction_coordinator.h"
 #include "mongo/s/shard_id.h"
-#include "mongo/s/shard_server_test_fixture.h"
 
 namespace mongo {
 
diff --git a/src/mongo/db/s/vector_clock_shard_server_test.cpp b/src/mongo/db/s/vector_clock_shard_server_test.cpp
index a2c7577769c..0f6af735ac6 100644
--- a/src/mongo/db/s/vector_clock_shard_server_test.cpp
+++ b/src/mongo/db/s/vector_clock_shard_server_test.cpp
@@ -32,10 +32,9 @@
 #include "mongo/db/keys_collection_client_direct.h"
 #include "mongo/db/keys_collection_manager.h"
 #include "mongo/db/logical_time_validator.h"
+#include "mongo/db/s/shard_server_test_fixture.h"
 #include "mongo/db/vector_clock_mutable.h"
-#include "mongo/s/shard_server_test_fixture.h"
 #include "mongo/unittest/death_test.h"
-#include "mongo/unittest/unittest.h"
 #include "mongo/util/clock_source_mock.h"
 
 namespace mongo {
diff --git a/src/mongo/db/service_context_d_test_fixture.cpp b/src/mongo/db/service_context_d_test_fixture.cpp
index 8c0b6b8abf5..a0b8caab275 100644
--- a/src/mongo/db/service_context_d_test_fixture.cpp
+++ b/src/mongo/db/service_context_d_test_fixture.cpp
@@ -90,6 +90,9 @@ ServiceContextMongoDTest::ServiceContextMongoDTest(std::string engine, RepairAct
     IndexAccessMethodFactory::set(serviceContext, std::make_unique<IndexAccessMethodFactoryImpl>());
     Collection::Factory::set(serviceContext, std::make_unique<CollectionImpl::FactoryImpl>());
     IndexBuildsCoordinator::set(serviceContext, std::make_unique<IndexBuildsCoordinatorMongod>());
+    CollectionShardingStateFactory::set(
+        getServiceContext(),
+        std::make_unique<CollectionShardingStateFactoryShard>(getServiceContext()));
 }
 
 ServiceContextMongoDTest::~ServiceContextMongoDTest() {
@@ -107,14 +110,6 @@ ServiceContextMongoDTest::~ServiceContextMongoDTest() {
     std::swap(storageGlobalParams.repair, _stashedStorageParams.repair);
 }
 
-void ServiceContextMongoDTest::setUp() {
-    ServiceContextTest::setUp();
-
-    CollectionShardingStateFactory::set(
-        getServiceContext(),
-        std::make_unique<CollectionShardingStateFactoryShard>(getServiceContext()));
-}
-
 void ServiceContextMongoDTest::tearDown() {
     {
         // Some tests set the current OperationContext but do not release it until destruction.
diff --git a/src/mongo/db/service_context_d_test_fixture.h b/src/mongo/db/service_context_d_test_fixture.h
index 0b25498a1a9..00f5f37883f 100644
--- a/src/mongo/db/service_context_d_test_fixture.h
+++ b/src/mongo/db/service_context_d_test_fixture.h
@@ -29,17 +29,15 @@
 
 #pragma once
 
-#include "mongo/db/operation_context.h"
 #include "mongo/db/service_context_test_fixture.h"
 #include "mongo/unittest/temp_dir.h"
-#include "mongo/unittest/unittest.h"
 
 namespace mongo {
 
 /**
  * Test fixture class for tests that use the "ephemeralForTest" storage engine.
  */
-class ServiceContextMongoDTest : public ServiceContextTest {
+class ServiceContextMongoDTest : public virtual ServiceContextTest {
 protected:
     enum class RepairAction { kNoRepair, kRepair };
 
@@ -52,8 +50,6 @@ protected:
     ServiceContextMongoDTest(std::string engine, RepairAction repair);
     virtual ~ServiceContextMongoDTest();
 
-    void setUp() override;
-
     void tearDown() override;
 
 private:
@@ -62,6 +58,7 @@ private:
         bool engineSetByUser;
         bool repair;
     } _stashedStorageParams;
+
     unittest::TempDir _tempDir;
 };
 
diff --git a/src/mongo/db/service_context_test_fixture.h b/src/mongo/db/service_context_test_fixture.h
index e7508898c0f..a1097c6a943 100644
--- a/src/mongo/db/service_context_test_fixture.h
+++ b/src/mongo/db/service_context_test_fixture.h
@@ -35,7 +35,6 @@
 
 namespace mongo {
 
-
 class ScopedGlobalServiceContextForTest {
 public:
     /**
diff --git a/src/mongo/db/vector_clock_mongod_test.cpp b/src/mongo/db/vector_clock_mongod_test.cpp
index a54b966b8f6..758db55118e 100644
--- a/src/mongo/db/vector_clock_mongod_test.cpp
+++ b/src/mongo/db/vector_clock_mongod_test.cpp
@@ -32,10 +32,9 @@
 #include "mongo/db/keys_collection_client_direct.h"
 #include "mongo/db/keys_collection_manager.h"
 #include "mongo/db/logical_time_validator.h"
+#include "mongo/db/s/sharding_mongod_test_fixture.h"
 #include "mongo/db/vector_clock_mutable.h"
-#include "mongo/s/sharding_mongod_test_fixture.h"
 #include "mongo/unittest/death_test.h"
-#include "mongo/unittest/unittest.h"
 #include "mongo/util/clock_source_mock.h"
 
 namespace mongo {