Using a non-standard SSH port

Issue

Neutree connects to nodes via SSH to manage static node clusters. The default SSH port is 22. If your nodes use a different port, adding nodes may fail.

Solution

Neutree uses Ray as the underlying cluster management tool. Because Ray does not support configuring the SSH port directly, use an SSH configuration file to configure a non-standard SSH port for each node.

Steps

1. Create an SSH configuration file and add node configurations.

   mkdir -p ./ssh-config
   cat > ./ssh-config/config << 'EOF'
   Host <host_alias>
       HostName <host_ip>
       Port <ssh_port>
       User <user>
   
   Host <host_alias>
       HostName <host_ip>
       Port <ssh_port>
       User <user>
   EOF
   chmod 600 ./ssh-config/config

   Parameter description:

   Parameter	Description
   <host_alias>	Node alias, used to identify the node in the SSH configuration and when adding the node to the cluster after configuration is complete.
   <host_ip>	IP address of the node.
   <ssh_port>	SSH port used by the node.
   <user>	SSH username. Must be root or another user with root privileges.

   Example

   mkdir -p ./ssh-config
   cat > ./ssh-config/config << 'EOF'
   Host gpu-node-1
       HostName 192.168.1.100
       Port 2222
       User root
   EOF
   chmod 600 ./ssh-config/config

   The example above creates ./ssh-config/config with the following configuration: node alias gpu-node-1, IP 192.168.1.100, port 2222, username root.

2. Mount the SSH configuration file to Neutree’s neutree-core container.

   Choose the appropriate method based on your deployment mode.

   Docker Compose

   1. Update the docker-compose.yaml file to mount the SSH configuration file to the neutree-core container.

      services:
        neutree-core:
          # ... other configurations
          volumes:
            - ./ssh-config:/root/.ssh:ro

   2. Restart the service.

      docker-compose up -d

   Note

   When upgrading the Neutree control plane using docker-compose.yaml in the future, your custom volume mounts may be overwritten. After each upgrade, be sure to remount the SSH configuration file to the neutree-core container.

   Kubernetes

   1. Create a ConfigMap containing the SSH configuration.

      kubectl create configmap ssh-config --from-file=config=./ssh-config -n neutree

      Or create the ConfigMap using a YAML file:

      apiVersion: v1
      kind: ConfigMap
      metadata:
        name: ssh-config
        namespace: neutree
      data:
        config: |
          Host gpu-node-1
              HostName 192.168.1.100
              Port 2222
              User root

   2. Update the neutree-core Deployment to mount the SSH configuration file.

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: neutree-core
        namespace: neutree
      spec:
        template:
          spec:
            containers:
              - name: neutree-core
                # ... other configurations
                volumeMounts:
                  - name: ssh-config
                    mountPath: /root/.ssh
                    readOnly: true
            volumes:
              - name: ssh-config
                configMap:
                  name: ssh-config
                  defaultMode: 0600

   3. Apply the configuration:

      kubectl apply -f neutree-core-deployment.yaml -n neutree

3. Test the SSH connection to each node to verify that the SSH configuration file and node configuration are correct.

4. Add nodes to the cluster in Neutree. Use the node alias (such as gpu-node-1 in the example above) instead of the IP address.

Related link

For Ray-related limitations, see Ray Discuss: Specify SSH port to cluster YAMLs.