SERVER-32205 Prohibit dropping the admin database at catalog level

(cherry picked from commit 72fc7cea722f952e3ad47c5470cb60ae2114097f)

4 files changed, 18 insertions, 71 deletions

diff --git a/jstests/multiVersion/set_feature_compatibility_version.js b/jstests/multiVersion/set_feature_compatibility_version.js
index abf6043546d..e831c1e2736 100644
--- a/jstests/multiVersion/set_feature_compatibility_version.js
+++ b/jstests/multiVersion/set_feature_compatibility_version.js
@@ -30,25 +30,6 @@ TestData.skipCheckingUUIDsConsistentAcrossCluster = true;
     };
 
     let doStartupFailTests = function(withUUIDs, dbpath) {
-        // Fail to start up if no admin database is present but other non-local databases are
-        // present.
-        if (withUUIDs) {
-            setupMissingAdminDB(latest, dbpath);
-        } else {
-            setupMissingAdminDB(downgrade, dbpath);
-        }
-        conn = MongoRunner.runMongod({dbpath: dbpath, binVersion: latest, noCleanData: true});
-        assert.eq(
-            null,
-            conn,
-            "expected mongod to fail when data files are present and no admin database is found.");
-        if (!withUUIDs) {
-            conn =
-                MongoRunner.runMongod({dbpath: dbpath, binVersion: downgrade, noCleanData: true});
-            assert.neq(null, conn, "expected 3.4 to startup when the admin database is missing");
-            MongoRunner.stopMongod(conn);
-        }
-
         // Fail to start up if no featureCompatibilityVersion document is present and non-local
         // databases are present.
         if (withUUIDs) {
@@ -93,20 +74,6 @@ TestData.skipCheckingUUIDsConsistentAcrossCluster = true;
         return conn;
     };
 
-    let setupMissingAdminDB = function(version, dbpath) {
-        conn = MongoRunner.runMongod({dbpath: dbpath, binVersion: version});
-        assert.neq(null,
-                   conn,
-                   "mongod was unable to start up with version=" + version + " and no data files");
-        let testDB = conn.getDB("test");
-        assert.commandWorked(testDB.createCollection("testcoll"));
-        adminDB = conn.getDB("admin");
-        assert.commandWorked(adminDB.runCommand({dropDatabase: 1}),
-                             "expected drop of admin database to be successful");
-        MongoRunner.stopMongod(conn);
-        return conn;
-    };
-
     //
     // Standalone tests.
     //
@@ -230,35 +197,11 @@ TestData.skipCheckingUUIDsConsistentAcrossCluster = true;
     // Fail to start up if no featureCompatibilityVersion is present and no collections have UUIDs.
     doStartupFailTests(/*withUUIDs*/ false, dbpath);
 
-    // --repair can be used to restore a missing admin database and featureCompatibilityVersion
-    // document if at least some collections have UUIDs.
-    conn = setupMissingAdminDB(latest, dbpath);
-    recoverMMapJournal(isMMAPv1, conn, dbpath);
-    let returnCode = runMongoProgram("mongod", "--port", conn.port, "--repair", "--dbpath", dbpath);
-    assert.eq(
-        returnCode,
-        0,
-        "expected mongod --repair to execute successfully when restoring a missing admin database.");
-    conn = MongoRunner.runMongod({dbpath: dbpath, binVersion: latest, noCleanData: true});
-    assert.neq(null,
-               conn,
-               "mongod was unable to start up with version=" + latest + " and existing data files");
-    // featureCompatibilityVersion is 3.4 and targetVersion is 3.6 because the admin.system.version
-    // collection was restored without a UUID.
-    adminDB = conn.getDB("admin");
-    assert.eq(adminDB.system.version.findOne({_id: "featureCompatibilityVersion"}).version, "3.4");
-    assert.eq(adminDB.system.version.findOne({_id: "featureCompatibilityVersion"}).targetVersion,
-              "3.6");
-    let adminInfos = adminDB.getCollectionInfos();
-    assert(!adminInfos[0].info.uuid,
-           "Expected collection with infos " + tojson(adminInfos) + " to not have a UUID.");
-    MongoRunner.stopMongod(conn);
-
     // --repair can be used to restore a missing featureCompatibilityVersion document to an
     // existing admin database if at least some collections have UUIDs.
     conn = setupMissingFCVDoc(latest, dbpath);
     recoverMMapJournal(isMMAPv1, conn, dbpath);
-    returnCode = runMongoProgram("mongod", "--port", conn.port, "--repair", "--dbpath", dbpath);
+    let returnCode = runMongoProgram("mongod", "--port", conn.port, "--repair", "--dbpath", dbpath);
     assert.eq(
         returnCode,
         0,
diff --git a/jstests/noPassthrough/feature_compatibility_version.js b/jstests/noPassthrough/feature_compatibility_version.js
index 016c5d12e08..f3824a3a0b5 100644
--- a/jstests/noPassthrough/feature_compatibility_version.js
+++ b/jstests/noPassthrough/feature_compatibility_version.js
@@ -91,9 +91,5 @@
         adminDB.system.version.insert({_id: "featureCompatibilityVersion", version: "3.6"}));
     checkFCV(adminDB, "3.6");
 
-    // Dropping the admin database changes the featureCompatibilityVersion server parameter to 3.4.
-    adminDB.dropDatabase();
-    checkFCVDocumentMissing(adminDB);
-
     MongoRunner.stopMongod(conn);
 }());
diff --git a/jstests/noPassthrough/system_indexes.js b/jstests/noPassthrough/system_indexes.js
index f95d7bf1a8d..3fa784e97da 100644
--- a/jstests/noPassthrough/system_indexes.js
+++ b/jstests/noPassthrough/system_indexes.js
@@ -47,10 +47,14 @@
 
     // TEST: Destroying the admin.system.users index and restarting will recreate it, even if
     // admin.system.roles does not exist
-    db.dropDatabase();
-    // Restore the featureCompatibilityVersion document since as of SERVER-29452, mongod fails to
-    // startup without such a document.
-    assert.commandWorked(db.runCommand({setFeatureCompatibilityVersion: "3.6"}));
+    // Use _mergeAuthzCollections to clear admin.system.users and admin.system.roles.
+    assert.commandWorked(db.adminCommand({
+        _mergeAuthzCollections: 1,
+        tempUsersCollection: 'admin.tempusers',
+        tempRolesCollection: 'admin.temproles',
+        db: "",
+        drop: true
+    }));
     db.createUser({user: "user", pwd: "pwd", roles: []});
     assert.commandWorked(db.system.users.dropIndexes());
     MongoRunner.stopMongod(conn);
@@ -60,10 +64,14 @@
 
     // TEST: Destroying the admin.system.roles index and restarting will recreate it, even if
     // admin.system.users does not exist
-    db.dropDatabase();
-    // Restore the featureCompatibilityVersion document since as of SERVER-29452, mongod fails to
-    // startup without such a document.
-    assert.commandWorked(db.runCommand({setFeatureCompatibilityVersion: "3.6"}));
+    // Use _mergeAuthzCollections to clear admin.system.users and admin.system.roles.
+    assert.commandWorked(db.adminCommand({
+        _mergeAuthzCollections: 1,
+        tempUsersCollection: 'admin.tempusers',
+        tempRolesCollection: 'admin.temproles',
+        db: "",
+        drop: true
+    }));
     db.createRole({role: "role", privileges: [], roles: []});
     assert.commandWorked(db.system.roles.dropIndexes());
     MongoRunner.stopMongod(conn);
diff --git a/jstests/replsets/drop_oplog.js b/jstests/replsets/drop_oplog.js
index df89ec255ff..8e2a7c2e1d2 100644
--- a/jstests/replsets/drop_oplog.js
+++ b/jstests/replsets/drop_oplog.js
@@ -22,7 +22,7 @@
     let adminDB = master.getDB('admin');
     dropOutput = adminDB.dropDatabase();
     assert.eq(dropOutput.ok, 0);
-    assert.eq(dropOutput.errmsg, "Cannot drop 'admin' database while replication is active");
+    assert.eq(dropOutput.errmsg, "Dropping the 'admin' database is prohibited.");
 
     let renameOutput = localDB.oplog.rs.renameCollection("poison");
     assert.eq(renameOutput.ok, 0);