IBM Cloud Docs
Logging in to a RHCOS host machine to debug

Logging in to a RHCOS host machine to debug

You might need to log in to your host machine to debug issues.

You can SSH into the host machine if you did not assign the host to a cluster, or if the assignment failed. Otherwise, Satellite disables the ability to log in to the host by using SSH for security purposes. You can remove the host and reload the operating system to restore the ability to SSH into the host machine.

  1. Download the host attach script and add your public SSH key.

    {
  "ignition": {
    "version": "3.1.0"
  },
  "passwd": {
    "users": [
      {
        "name": "core",
        "sshAuthorizedKeys": [ "PUBLIC-SSH-KEY" ]
      }
    ]
  },
...
}

  2. Log in to your host as core.

    ssh core@<IP_address>

  3. Run the following journalctl commands when you attempt to attach your host again to log the systemd service that is causing the issue.

    journalctl -u ibm-host-attach --no-pager

    journalctl -u ibm-host-agent --no-pager

    journalctl -u ibm-firstboot-ignition --no-pager

  4. Review the logs for errors. See the following section for more details.

Machine cannot be reached on the network

You receive output similar to the following messages.

curl: (6) Could not resolve host

The machine cannot be reached on the network. Check that your machine meets the minimum requirements for network connectivity, remove the host, and try to add and assign the host again.

Alternatively, the infrastructure provider network might have issues, such as a failed connection. Consult the infrastructure provider documentation for further debugging steps.