I wrote an SSH step for you. Here's the source code:
https://github.com/relay-integrations/relay-ssh/blob/master/...
And since it isn't documented yet, here's how you would use it in a workflow:
steps: - name: ssh image: relaysh/ssh-step-exec spec: connection: !Connection {type: ssh, name: my-ssh-connection} username: relay port: 2222 # defaults to 22 knownHosts: | server1.example.com ssh-rsa AAAAEXAMPLE server2.example.com ssh-rsa AAAANOTHEREXAMPLE # or #strictHostKeyChecking: false on: - server1.example.com - server2.example.com input: - whoami - uptime - cat /etc/passwd