SERVER-24611 Implement ClientMetadata class

Author: markbenvenuto

jstests/core/client_metadata_ismaster.js

@@ -0,0 +1,12 @@
+// Test that verifies client metadata behavior for isMaster
+
+(function() {
+    "use strict";
+
+    // Verify that a isMaster request fails if it contains client metadata, and it is not first.
+    // The shell sends isMaster on the first connection
+    var result = db.runCommand({"isMaster": 1, "client": {"application": "foobar"}});
+    assert.commandFailed(result);
+    assert.eq(result.code, ErrorCodes.ClientMetadataCannotBeMutated, tojson(result));
+
+})();

jstests/noPassthrough/currentop_query.js

@@ -71,6 +71,8 @@
                     assert.commandWorked(result);
 
                     if (result.inprog.length === 1) {
+                        assert.eq(result.inprog[0].appName, "MongoDB Shell", tojson(result));
+
                         return true;
                     }
 

src/mongo/base/error_codes.err

@@ -181,6 +181,10 @@ error_code("WindowsPdhError", 179)
 error_code("BadPerfCounterPath", 180)
 error_code("AmbiguousIndexKeyPattern", 181)
 error_code("InvalidViewDefinition", 182);
+error_code("ClientMetadataMissingField", 183)
+error_code("ClientMetadataAppNameTooLarge", 184)
+error_code("ClientMetadataDocumentTooLarge", 185)
+error_code("ClientMetadataCannotBeMutated", 186)
 
 # Non-sequential error codes (for compatibility only)
 error_code("SocketException", 9001)

src/mongo/client/connection_pool.cpp

@@ -184,7 +184,7 @@ ConnectionPool::ConnectionList::iterator ConnectionPool::acquireConnection(
     // the number of seconds with a fractional part.
     conn->setSoTimeout(durationCount<Milliseconds>(timeout) / 1000.0);
 
-    uassertStatusOK(conn->connect(target));
     conn->port().setTag(conn->port().getTag() | _messagingPortTags);
 
     if (isInternalAuthSet()) {

src/mongo/client/connection_string.h

@@ -116,7 +116,9 @@ class ConnectionString {
     bool operator==(const ConnectionString& other) const;
     bool operator!=(const ConnectionString& other) const;
 
-    DBClientBase* connect(std::string& errmsg, double socketTimeout = 0) const;
+                          std::string& errmsg,
+                          double socketTimeout = 0) const;
 
     static StatusWith<ConnectionString> parse(const std::string& url);
 

src/mongo/client/connection_string_connect.cpp

@@ -45,21 +45,24 @@ namespace mongo {
 stdx::mutex ConnectionString::_connectHookMutex;
 ConnectionString::ConnectionHook* ConnectionString::_connectHook = NULL;
 
-DBClientBase* ConnectionString::connect(std::string& errmsg, double socketTimeout) const {
+                                        std::string& errmsg,
+                                        double socketTimeout) const {
     switch (_type) {
         case MASTER: {
             auto c = stdx::make_unique<DBClientConnection>(true);
             c->setSoTimeout(socketTimeout);
             LOG(1) << "creating new connection to:" << _servers[0];
-            if (!c->connect(_servers[0], errmsg)) {
                 return 0;
             }
             LOG(1) << "connected connection!";
             return c.release();
         }
 
         case SET: {
-            auto set = stdx::make_unique<DBClientReplicaSet>(_setName, _servers, socketTimeout);
+                _setName, _servers, applicationName, socketTimeout);
             if (!set->connect()) {
                 errmsg = "connect failed to replica set ";
                 errmsg += toString();

src/mongo/client/connpool.cpp

@@ -235,7 +235,7 @@ DBClientBase* DBConnectionPool::get(const ConnectionString& url, double socketTi
     }
 
     string errmsg;
-    c = url.connect(errmsg, socketTimeout);
     uassert(13328, _name + ": connect failed " + url.toString() + " : " + errmsg, c);
 
     return _finishCreate(url.toString(), socketTimeout, c);
@@ -256,7 +256,7 @@ DBClientBase* DBConnectionPool::get(const string& host, double socketTimeout) {
     const ConnectionString cs(uassertStatusOK(ConnectionString::parse(host)));
 
     string errmsg;
-    c = cs.connect(errmsg, socketTimeout);
     if (!c)
         throw SocketException(SocketException::CONNECT_ERROR,
                               host,

src/mongo/client/dbclient.cpp

@@ -55,6 +55,7 @@
 #include "mongo/rpc/factory.h"
 #include "mongo/rpc/get_status_from_command_result.h"
 #include "mongo/rpc/metadata.h"
+#include "mongo/rpc/metadata/client_metadata.h"
 #include "mongo/rpc/reply_interface.h"
 #include "mongo/rpc/request_builder_interface.h"
 #include "mongo/s/stale_exception.h"  // for RecvStaleConfigException
@@ -74,6 +75,7 @@
 #include "mongo/util/password_digest.h"
 #include "mongo/util/represent_as.h"
 #include "mongo/util/time_support.h"
+#include "mongo/util/version.h"
 
 namespace mongo {
 
@@ -712,7 +714,8 @@ class ScopedForceOpQuery {
 /**
 * Initializes the wire version of conn, and returns the isMaster reply.
 */
-executor::RemoteCommandResponse initWireVersion(DBClientConnection* conn) {
+                                                StringData applicationName) {
     try {
         // We need to force the usage of OP_QUERY on this command, even if we have previously
         // detected support for OP_COMMAND on a connection. This is necessary to handle the case
@@ -731,6 +734,12 @@ executor::RemoteCommandResponse initWireVersion(DBClientConnection* conn) {
             bob.append("hostInfo", sb.str());
         }
 
+        Status serializeStatus = ClientMetadata::serialize(
+            "MongoDB Internal Client", mongo::versionString, applicationName, &bob);
+        if (!serializeStatus.isOK()) {
+            return serializeStatus;
+        }
+
         Date_t start{Date_t::now()};
         auto result =
             conn->runCommandWithMetadata("admin", "isMaster", rpc::makeEmptyMetadata(), bob.done());
@@ -754,22 +763,25 @@ executor::RemoteCommandResponse initWireVersion(DBClientConnection* conn) {
 
 }  // namespace
 
-bool DBClientConnection::connect(const HostAndPort& server, std::string& errmsg) {
-    auto connectStatus = connect(server);
+                                 std::string& errmsg) {
+    auto connectStatus = connect(server, applicationName);
     if (!connectStatus.isOK()) {
         errmsg = connectStatus.reason();
         return false;
     }
     return true;
 }
 
-Status DBClientConnection::connect(const HostAndPort& serverAddress) {
     auto connectStatus = connectSocketOnly(serverAddress);
     if (!connectStatus.isOK()) {
         return connectStatus;
     }
 
-    auto swIsMasterReply = initWireVersion(this);
+    auto swIsMasterReply = initWireVersion(this, applicationName);
     if (!swIsMasterReply.isOK()) {
         _failed = true;
         return swIsMasterReply.status;
@@ -903,7 +915,7 @@ void DBClientConnection::_checkConnection() {
     LOG(_logLevel) << "trying reconnect to " << toString() << endl;
     string errmsg;
     _failed = false;
-    auto connectStatus = connect(_serverAddress);
     if (!connectStatus.isOK()) {
         _failed = true;
         LOG(_logLevel) << "reconnect " << toString() << " failed " << errmsg << endl;

src/mongo/client/dbclient_rs.cpp

@@ -135,8 +135,9 @@ bool DBClientReplicaSet::_authPooledSecondaryConn = true;
 
 DBClientReplicaSet::DBClientReplicaSet(const string& name,
                                        const vector<HostAndPort>& servers,
+                                       StringData applicationName,
                                        double so_timeout)
-    : _setName(name), _so_timeout(so_timeout) {
     _rsm =
         ReplicaSetMonitor::createIfNeeded(name, set<HostAndPort>(servers.begin(), servers.end()));
 }
@@ -303,7 +304,8 @@ DBClientConnection* DBClientReplicaSet::checkMaster() {
         // Needs to perform a dynamic_cast because we need to set the replSet
         // callback. We should eventually not need this after we remove the
         // callback.
-        newConn = dynamic_cast<DBClientConnection*>(connStr.connect(errmsg, _so_timeout));
+            connStr.connect(_applicationName, errmsg, _so_timeout));
     } catch (const AssertionException& ex) {
         errmsg = ex.toString();
     }

src/mongo/client/dbclient_rs.h

@@ -59,6 +59,7 @@ class DBClientReplicaSet : public DBClientBase {
      * connections. */
     DBClientReplicaSet(const std::string& name,
                        const std::vector<HostAndPort>& servers,
+                       StringData applicationName,
                        double so_timeout = 0);
     virtual ~DBClientReplicaSet();
 
@@ -295,6 +296,7 @@ class DBClientReplicaSet : public DBClientBase {
     ReplicaSetMonitorPtr _getMonitor();
 
     std::string _setName;
+    std::string _applicationName;
     std::shared_ptr<ReplicaSetMonitor> _rsm;
 
     HostAndPort _masterHost;