My friend and I are trying to connect our Docker daemon using Docker Swarm. We both are using Windows OS and we are NOT on the same network. According to Docker docs each docker host must have the following ports open;
TCP port 2377 for cluster management communications TCP and UDP port 7946 for communication among nodes UDP port 4789 for overlay network traffic
We both have added new rules for the given ports in inbound and outbound rules in the firewall. Though we keep getting the same two errors while trying to join using token created by the manager node using docker swarm join --token command;
1. error response from daemon: rpc error: code = Unavailable desc = connection error: desc = "transport: Error while dialing dial tcp 192.168.65.3:2377: connect: connection refused"
2. Timeout error
Also, if either of us runs docker swarm init it shows 192.168.65.3 IP address that isn't part of any network we're connected to. What does it mean?
Docker overlay tutorial also states that in order to connect to the manager node, the worker node should add the IP address of the manager.
docker swarm join --token \ --advertise-addr IP-ADDRESS-OF-WORKER-1
IP-ADDRESS-OF-MANAGER:2377
Does it mean that in our case we have to use public IP address of the manager node after enabling port forwarding?
Potential network issues aside, here is your problem:
We both are using Windows OS
I have seen this issue in other threads when attempting to use Windows nodes in a multi-node swarm. Here are some important pieces of information from the Docker overlay networks documentation:
Before you can create an overlay network, you need to either initialize your Docker daemon as a swarm manager using
docker swarm initor join it to an existing swarm usingdocker swarm join. Either of these creates the default ingress overlay network which is used by swarm services by default.
Overlay network encryption is not supported on Windows. If a Windows node attempts to connect to an encrypted overlay network, no error is detected but the node cannot communicate.
By default, Docker encrypts all swarm service management traffic. As far as I know, disabling this encryption is not possible. Do not confuse this with the --opt encrypted option, as that involves encrypting application data, not swarm management traffic.
For a single-node swarm, using Windows is just fine. For a multi-node swarm, which would be deployed using Docker stack, I highly recommend using Linux for all worker and manager nodes.
A while ago I was using Linux as a manager node and Windows as a worker node. I noticed that joining the swarm would only work if the Linux machine was the swarm manager; If the Windows machine was the manager, joining the swarm would not work. After the Windows machine joined the swarm, container-to-container communication over a user-defined overlay network would not work no matter what. Replacing the Windows machine with a Linux machine fixed all issues.