SERVER-22230 add command-line setting for readOnly mode

5 files changed, 37 insertions, 1 deletions

diff --git a/jstests/noPassthrough/read_only_command_line.js b/jstests/noPassthrough/read_only_command_line.js
new file mode 100644
index 00000000000..c7eb52a1de3
--- /dev/null
+++ b/jstests/noPassthrough/read_only_command_line.js
@@ -0,0 +1,19 @@
+// Test that setting readOnly mode on the command line causes readOnly to be properly set in both
+// isMaster and serverStatus output.
+(function() {
+    "use strict";
+
+    var mongod = MongoRunner.runMongod();
+
+    // ensure dbpath gets set up.
+    assert.writeOK(mongod.getDB("foo").x.insert({x:1}));
+
+    assert(!mongod.getDB("admin").isMaster().readOnly);
+    assert(!mongod.getDB("admin").serverStatus().storageEngine.readOnly);
+    MongoRunner.stopMongod(mongod);
+
+    mongod = MongoRunner.runMongod({readOnly: ""});
+    assert(mongod.getDB("admin").isMaster().readOnly);
+    assert(mongod.getDB("admin").serverStatus().storageEngine.readOnly);
+    MongoRunner.stopMongod(mongod);
+}());
diff --git a/src/mongo/db/mongod_options.cpp b/src/mongo/db/mongod_options.cpp
index 22aa06653b4..8d4e22b8bfa 100644
--- a/src/mongo/db/mongod_options.cpp
+++ b/src/mongo/db/mongod_options.cpp
@@ -204,6 +204,14 @@ Status addMongodOptions(moe::OptionSection* options) {
                                       moe::Switch,
                                       "each database will be stored in a separate directory");
 
+    storage_options.addOptionChaining(
+                        "storage.readOnly",
+                        "readOnly",
+                        moe::Switch,
+                        "enable read-only mode - if true the server will not accept writes.")
+        .setSources(moe::SourceAll);
+
+
     general_options.addOptionChaining(
                         "noIndexBuildRetry",
                         "noIndexBuildRetry",
@@ -1016,6 +1024,11 @@ Status storeMongodOptions(const moe::Environment& params, const std::vector<std:
     if (params.count("storage.directoryPerDB")) {
         storageGlobalParams.directoryperdb = params["storage.directoryPerDB"].as<bool>();
     }
+
+    if (params.count("storage.readOnly")) {
+        storageGlobalParams.readOnly = params["storage.readOnly"].as<bool>();
+    }
+
     if (params.count("cpu")) {
         serverGlobalParams.cpu = params["cpu"].as<bool>();
     }
diff --git a/src/mongo/db/repl/replication_info.cpp b/src/mongo/db/repl/replication_info.cpp
index 273deaa3bd9..211ba0ff89a 100644
--- a/src/mongo/db/repl/replication_info.cpp
+++ b/src/mongo/db/repl/replication_info.cpp
@@ -239,6 +239,7 @@ public:
         result.appendDate("localTime", jsTime());
         result.append("maxWireVersion", WireSpec::instance().maxWireVersionIncoming);
         result.append("minWireVersion", WireSpec::instance().minWireVersionIncoming);
+        result.append("readOnly", storageGlobalParams.readOnly);
         return true;
     }
 } cmdismaster;
diff --git a/src/mongo/db/storage/storage_init.cpp b/src/mongo/db/storage/storage_init.cpp
index a90ddecfe25..bb4470e7ba4 100644
--- a/src/mongo/db/storage/storage_init.cpp
+++ b/src/mongo/db/storage/storage_init.cpp
@@ -55,7 +55,8 @@ public:
     virtual BSONObj generateSection(OperationContext* txn, const BSONElement& configElement) const {
         auto engine = txn->getClient()->getServiceContext()->getGlobalStorageEngine();
         return BSON("name" << storageGlobalParams.engine << "supportsCommittedReads"
-                           << bool(engine->getSnapshotManager()));
+                           << bool(engine->getSnapshotManager()) << "readOnly"
+                           << storageGlobalParams.readOnly);
     }
 
 } storageSSS;
diff --git a/src/mongo/db/storage/storage_options.h b/src/mongo/db/storage/storage_options.h
index ba20d76dd78..2e4f936e60e 100644
--- a/src/mongo/db/storage/storage_options.h
+++ b/src/mongo/db/storage/storage_options.h
@@ -99,6 +99,8 @@ struct StorageGlobalParams {
     // Do not set this value on production systems.
     // In almost every situation, you should use the default setting.
     AtomicDouble syncdelay{60.0};  // seconds between fsyncs
+
+    bool readOnly = false;
 };
 
 extern StorageGlobalParams storageGlobalParams;