Cannot connect to replica set via mongo compass

[steevej (Steeve Juneau)]

@rliu

mongodb://localhost:27017,localhost:27018,localhost:27019/?replicaSet=myReplicaSet&tls=false

This is not what I proposed. The replica set is not configured as as localhost. So you are specifying the wrong host. From the link you supplied the replica set is:

docker exec -it mongo1 mongosh --eval "rs.initiate({
 _id: \"myReplicaSet\",
 members: [
   {_id: 0, host: \"mongo1\"},
   {_id: 1, host: \"mongo2\"},
   {_id: 2, host: \"mongo3\"}
 ]
})"

@rliu

mongodb://mongo1:27017,mongo2:27018,mongo3:27019/?replicaSet=myReplicaSet&tls=false

This is again not what I proposed. I mentioned

@steevej

the nodes are named mongo1, mongo2 and mongo3, and they all listen on port 27017

and

@steevej

You may leave the port number since you are using the default one.

So you are mentioning the wrong ports.

@rliu

mongodb://mongo1:27017,mongo2:27018,mongo3:27019/?replicaSet=myReplicaSet&readPreference=primary&appname=MongoDB%20Compass&directConnection=false&ssl=false

As already mentioned you are specifying the wrong ports.

@rliu

mongodb://172.20.0.1:27017,172.20.0.2:27018,172.20.0.3:27019/?replicaSet=myReplicaSet&readPreference=primary&directConnection=false&ssl=false

I have mentioned that your replica set, if configured like the link you shared is configured with

@steevej

the nodes are named mongo1, mongo2 and mongo3

So with 127.0.0.1 you are mentioning the wrong hosts.

The conclusion is that you have tried many things. The one thing you have not tried is the one I have mentioned:

@steevej

If the following connection string does not work please provide the error you are getting.

mongodb://mongo1,mongo2,mongo3/?replicaSet=myReplicaSet

Since you have tried many things except the one I shared I am not too sure that you

@rliu

followed the Mongo instruction

because you do not follow the only suggestion I offer. Please share the output of

docker ps 
and
docker exec -it mongo1 mongosh --eval "rs.status()"

Hopefully, they match what is documented in the link you shared.

Share the screenshot of the connection string that generated the Compass error

@rliu

getaddrinfo ENOTFOUND mongo1/2/3