Ignore failures when killing the SSH agent

A failure to kill the agent in the post-action step will no longer fail the workflow run. That way, you can kill the agent yourself when necessary (#33).

Support self-hosted runners

This release includes the contribution by @thommyhh from #27.

Unless the SSH_AUTH_SOCK is configured explicitly, the SSH agent will now use a random file name for the socket. That way, multiple, concurrent SSH agents can be used on non-ephemeral, self-hosted runners.

A new post-action step will automatically clean up the running agent at the end of a job.

Be aware of the possible security implications: Two jobs running on the same runner might be able to access each other's socket and thus access repositories and/or hosts.

Supports multiple keys

This release adds support for using multiple SSH keys. It also improves UX by giving a clear error message when you forgot to configure the SSH keys as secret values.

Support MacOS worker nodes as well

Fixes #1 by adding OS X support

Initial Release

This action

• starts the ssh-agent,
• exports the SSH_AUTH_SOCK environment variable,
• loads a private SSH key into the agent and
• configures known_hosts for GitHub.com.

Why?

When running a GitHub Action workflow to stage your project, run tests or build images, you might need to fetch additional libraries or vendors from private repositories.

GitHub Actions only have access to the repository they run for. So, in order to access additional private repositories, create an SSH key with sufficient access privileges. Then, use this action to make the key available with ssh-agent on the Action worker node. Once this has been set up, git clone commands using ssh URLs will just work. Also, running ssh commands to connect to other servers will be able to use the key.