是否可以使用mgo驱动程序运行mongo复制集命令？

Question

Is it possible to run replica set commands like rs.initiate() and rs.add() using mgo driver from a golang application?

If yes, how??

Answer 1

Thanks to @alex-blex's answer which gave me the start. But this is what finally worked for me:

session, err := mgo.Dial("rs1.example.net?connect=direct")
if err != nil {
    panic(err)
}
defer session.Close()
session.SetMode(mgo.Monotonic, true)

config := bson.M{
    "_id": "my_replica_set",
    "members": []bson.M{
        {"_id": 0, "host": "rs1.example.net:27017"},
        {"_id": 1, "host": "rs2.example.net:27017", "priority": 2},
        {"_id": 2, "host": "rs3.example.net", "arbiterOnly": true},
    },
}
result := bson.M{}
if err := session.Run(bson.M{"replSetInitiate": config}, &result); err != nil {
    panic(err)
}

Notice the following:

1. ?connect=direct in the connection string.

   If not specified, the connection will timeout, probably because the replica set has not been initialized yet.

2. session.SetMode(mgo.Monotonic, true)

   Session mode should be monotonic as the default session used by mgo is primary which performs all operations on primary. Since the replica set has not been initialized yet, there wont be a primary and the operation (in this case, replSetInitiate) will just timeout

3. "_id": "my_replica_set" in the config

   For this to work, the mongo servers will have to be started with the replica set name my_replica_set. One way of doing that would be:

   mongod --replSet my_replica_set
   

4. As per Mgo docs use session.Run() for commands on the "admin" database