name: Set up tailnet + SSH
description: >-
  Join Tailscale and load the deploy SSH key into an agent, so tofu's Proxmox
  (bpg) provider can reach london-a's API and node over the tailnet.

inputs:
  tailscale-client-id:
    required: true
  tailscale-audience:
    required: true
  ssh-private-key:
    required: true

runs:
  using: composite
  steps:
    - name: Set up Tailscale
      uses: tailscale/github-action@v4
      with:
        oauth-client-id: ${{ inputs.tailscale-client-id }}
        audience: ${{ inputs.tailscale-audience }}
        tags: tag:ci

    - name: Load SSH key into agent
      shell: bash
      run: |
        mkdir -p ~/.ssh
        echo "${{ inputs.ssh-private-key }}" > ~/.ssh/id_ed25519
        chmod 600 ~/.ssh/id_ed25519
        eval "$(ssh-agent -s)"
        ssh-add ~/.ssh/id_ed25519
        # Persist the agent for later steps (bpg uses SSH_AUTH_SOCK).
        echo "SSH_AUTH_SOCK=$SSH_AUTH_SOCK" >> "$GITHUB_ENV"
        echo "SSH_AGENT_PID=$SSH_AGENT_PID" >> "$GITHUB_ENV"
        ssh-keyscan -H 100.122.180.98 >> ~/.ssh/known_hosts 2>/dev/null || true