SERVER-1292 For now, don't add a mongod as a shard if it's not empty. Will allow that next.

4 files changed, 61 insertions, 3 deletions

diff --git a/jstests/sharding/addshard1.js b/jstests/sharding/addshard1.js
new file mode 100644
index 00000000000..5e299770fff
--- /dev/null
+++ b/jstests/sharding/addshard1.js
@@ -0,0 +1,12 @@
+s = new ShardingTest( "add_shard1", 1 );
+
+assert.eq( 1, s.config.shards.count(), "initial server count wrong" );
+
+// create a shard and add a database; a non-empty mongod should not be accepted as a shard
+conn = startMongodTest( 29000 );
+db = conn.getDB( "test" );
+db.foo.save( {a:1} );
+assert( ! s.admin.runCommand( { addshard: "localhost:29000" } ).ok, "accepted non-empty shard" );
+
+stopMongod( 29000 );
+s.stop();
\ No newline at end of file
diff --git a/s/commands_admin.cpp b/s/commands_admin.cpp
index af50422cba4..de47fd4a51b 100644
--- a/s/commands_admin.cpp
+++ b/s/commands_admin.cpp
@@ -620,6 +620,7 @@ namespace mongo {
                 if ( shardAddr.isLocalHost() != grid.allowLocalHost() ){
                     errmsg = "can't use localhost as a shard since all shards need to communicate. "
                              "either use all shards and configdbs in localhost or all in actual IPs " ;
+                    log() << "addshard request " << cmdObj << " failed: attempt to mix localhosts and IPs" << endl;
                     return false;
                 }
 
@@ -639,7 +640,7 @@ namespace mongo {
                 }
                 
                 if ( ! grid.addShard( &name , shardAddr.toString() , maxSize , &errmsg ) ){
-                    // addShard filled errmsg
+                    log() << "addshard request " << cmdObj << " failed: " << errmsg << endl;
                     return false;
                 }
 
diff --git a/s/grid.cpp b/s/grid.cpp
index e1e6c4b40a5..c3d8e3ad7a0 100644
--- a/s/grid.cpp
+++ b/s/grid.cpp
@@ -21,6 +21,7 @@
 #include <iomanip>
 
 #include "../client/connpool.h"
+#include "../util/stringutils.h"
 
 #include "grid.h"
 #include "shard.h"
@@ -118,6 +119,40 @@ namespace mongo {
         try {
             ScopedDbConnection newShardConn( host );
             newShardConn->getLastError();
+
+            // get the shard's local db's listing
+            BSONObj res;
+            bool ok = newShardConn->runCommand( "admin" , BSON( "listDatabases" << 1 ) , res );
+            if ( !ok ){
+                ostringstream ss;
+                ss << "failed listing " << host << " databases:" << res;
+                *errMsg = ss.str();
+                newShardConn.done();
+                return false;
+            }
+
+            vector<string> dbNames;
+            BSONObjIterator i( res["databases"].Obj() );
+            while ( i.more() ){
+                BSONObj dbEntry = i.next().Obj();
+                const string& dbName = dbEntry["name"].String();
+                if ( ! _isSpecialLocalDB( dbName ) ){
+                    dbNames.push_back( dbName );
+                }
+            }
+
+            // TODO (within SERVER-1292) If the databases aren't duplicate, add them to the grid
+            if ( ! dbNames.empty() ){
+                string dbConcat;
+                joinStringDelim( dbNames, &dbConcat , ',' );
+                ostringstream ss;
+                ss << "cannot add shard " << host << " that has local databases: " << dbConcat;
+                *errMsg = ss.str();
+
+                newShardConn.done();
+                return false;
+            }
+
             newShardConn.done();
         }
         catch ( DBException& e ){
@@ -134,7 +169,7 @@ namespace mongo {
             return false;
         }
             
-        // build the ConfigDB shard document.
+        // build the ConfigDB shard document
         BSONObjBuilder b;
         b.append( "_id" , *name );
         b.append( "host" , host );
@@ -146,7 +181,7 @@ namespace mongo {
         {
             ScopedDbConnection conn( configServer.getPrimary() );
                 
-            // check whether this host:port is already a known shard
+            // check whether this host:port is not an already a known shard
             BSONObj old = conn->findOne( ShardNS::shard , BSON( "host" << host ) );
             if ( ! old.isEmpty() ){
                 *errMsg = "host already used";
@@ -160,6 +195,7 @@ namespace mongo {
             *errMsg = conn->getLastError();
             if ( ! errMsg->empty() ){
                 log() << "error adding shard: " << shardDoc << " err: " << *errMsg << endl;
+                conn.done();
                 return false;
             }
 
@@ -221,6 +257,10 @@ namespace mongo {
         return result["optime"]._numberLong();
     }
 
+    bool Grid::_isSpecialLocalDB( const string& dbName ){
+        return ( dbName == "local" ) || ( dbName == "admin" ) || ( dbName == "config" );
+    }
+
     Grid grid;
 
 } 
diff --git a/s/grid.h b/s/grid.h
index c255c45bae7..ffd6d4ac2a1 100644
--- a/s/grid.h
+++ b/s/grid.h
@@ -94,6 +94,11 @@ namespace mongo {
          */
         bool _getNewShardName( string* name ) const;
 
+        /**
+         * @return whether a give dbname is used for shard "local" databases (e.g., admin or local)
+         */
+        static bool _isSpecialLocalDB( const string& dbName );
+
     };
 
     extern Grid grid;