action.yml

# Copyright (c) Tailscale Inc & AUTHORS
# SPDX-License-Identifier: BSD-3-Clause
#
name: 'Connect Tailscale'
description: 'Connect your GitHub Action workflow to Tailscale'
branding:
  icon: 'arrow-right-circle'
  color: 'gray-dark'
inputs:
  authkey:
    description: 'Your Tailscale authentication key, from the admin panel.'
    required: false
    deprecationMessage: 'An OAuth API client https://tailscale.com/s/oauth-clients is recommended instead of an authkey'
  oauth-client-id:
    description: 'Your Tailscale OAuth Client ID.'
    required: false
  oauth-secret:
    description: 'Your Tailscale OAuth Client Secret.'
    required: false
  tags:
    description: 'Comma separated list of Tags to be applied to nodes. The OAuth client must have permission to apply these tags.'
    required: false
  version:
    description: 'Tailscale version to use. Specify `latest` to use the latest stable version, and `unstable` to use the latest development version.'
    required: true
    default: '1.88.3'
  sha256sum:
    description: 'Expected SHA256 checksum of the tarball.'
    required: false
    default: ''
  args:
    description: 'Optional additional arguments to `tailscale up`'
    required: false
    default: ''
  tailscaled-args:
    description: 'Optional additional arguments to `tailscaled`'
    required: false
    default: ''
  hostname:
    description: 'Fixed hostname to use. Must be a valid DNS label (alphanumeric and dashes only, 1-63 characters, cannot start or end with a dash). If not provided, a hostname will be generated based on the runner name.'
    required: false
    default: ''
  statedir:
    description: 'Optional state directory to use (if unset, memory state is used)'
    required: false
    default: ''
  timeout:
    description: 'Timeout for `tailscale up`'
    required: false
    default: '2m'
  retry:
    description: 'Number of retries for `tailscale up`'
    required: false
    default: '5'
  use-cache:
    description: 'Whether to cache the Tailscale binaries (Linux/macOS) or installer (Windows)'
    required: false
    default: 'false'
  targets:
    description: 'Comma separated list of targets (Tailscale IP addresses or machine names if MagicDNS is enabled on the tailnet) to `tailscale ping` for connectivity verification after `tailscale up` completes'
    required: false
    default: ''
runs:
    using: 'composite'
    steps:
      - name: Check Runner OS
        if: ${{ runner.os != 'Linux' && runner.os != 'Windows' && runner.os != 'macOS'}}
        shell: bash
        run: |
          echo "::error title=⛔ error hint::Support Linux, Windows, and macOS Only"
          exit 1
      - name: Check Auth Info Empty
        if: ${{ inputs.authkey == '' && (inputs['oauth-secret'] == '' || inputs.tags == '') }}
        shell: bash
        run: |
          echo "::error title=⛔ error hint::OAuth identity empty, Maybe you need to populate it in the Secrets for your workflow, see more in https://docs.github.com/en/actions/security-guides/encrypted-secrets and https://tailscale.com/s/oauth-clients"
          exit 1

      - name: Set Resolved Version
        shell: bash
        run: |
          VERSION=${{ inputs.version }}
          if [ "$VERSION" = "latest" ]; then
            RESOLVED_VERSION=$(curl -H user-agent:tailscale-github-action -s "https://pkgs.tailscale.com/stable/?mode=json" | jq -r .Version)
          elif [ "$VERSION" = "unstable" ]; then
            RESOLVED_VERSION=$(curl -H user-agent:tailscale-github-action -s "https://pkgs.tailscale.com/unstable/?mode=json" | jq -r .Version)
          else
            RESOLVED_VERSION=$VERSION
          fi
          echo "RESOLVED_VERSION=$RESOLVED_VERSION" >> $GITHUB_ENV
          echo "Resolved Tailscale version: $RESOLVED_VERSION"
      - name: Set Tailscale Architecture - Linux
        if: ${{ runner.os == 'Linux' }}
        shell: bash
        run: |
          if [ ${{ runner.arch }} = "ARM64" ]; then
            TS_ARCH="arm64"
          elif [ ${{ runner.arch }} = "ARM" ]; then
            TS_ARCH="arm"
          elif [ ${{ runner.arch }} = "X86" ]; then
            TS_ARCH="386"
          else
            TS_ARCH="amd64"
          fi
          echo "TS_ARCH=$TS_ARCH" >> $GITHUB_ENV

      - name: Set Tailscale Architecture - Windows
        if: ${{ runner.os == 'Windows' }}
        shell: bash
        run: |
          if [ ${{ runner.arch }} = "ARM64" ]; then
            TS_ARCH="arm64"
          elif [ ${{ runner.arch }} = "X86" ]; then
            TS_ARCH="x86"
          else
            TS_ARCH="amd64"
          fi
          echo "TS_ARCH=$TS_ARCH" >> $GITHUB_ENV

      - name: Set SHA256 - Linux
        if: ${{ runner.os == 'Linux' }}
        shell: bash
        run: |
          MINOR=$(echo "$RESOLVED_VERSION" | awk -F '.' {'print $2'})
          if [ $((MINOR % 2)) -eq 0 ]; then
            URL="https://pkgs.tailscale.com/stable/tailscale_${RESOLVED_VERSION}_${TS_ARCH}.tgz.sha256"
          else
            URL="https://pkgs.tailscale.com/unstable/tailscale_${RESOLVED_VERSION}_${TS_ARCH}.tgz.sha256"
          fi
          
          if [[ "${{ inputs.sha256sum }}" ]]; then
            SHA256SUM="${{ inputs.sha256sum }}"
          else
            SHA256SUM="$(curl -H user-agent:tailscale-github-action -L "${URL}" --fail)"
          fi
          echo "SHA256SUM=$SHA256SUM" >> $GITHUB_ENV
          
      - name: Restore Tailscale Binary - Linux
        if: ${{ inputs.use-cache == 'true' && runner.os == 'Linux' }}
        uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
        id: restore-cache-tailscale-linux
        with:
          path: tailscale.tgz
          key: ${{ runner.os }}-tailscale-${{ env.RESOLVED_VERSION }}-${{ env.TS_ARCH }}-${{ env.SHA256SUM }}

      - name: Download Tailscale - Linux
        if: ${{ runner.os == 'Linux' && (inputs.use-cache != 'true' || steps.restore-cache-tailscale-linux.outputs.cache-hit != 'true') }}
        shell: bash
        run: |
          MINOR=$(echo "$RESOLVED_VERSION" | awk -F '.' {'print $2'})
          if [ $((MINOR % 2)) -eq 0 ]; then
            URL="https://pkgs.tailscale.com/stable/tailscale_${RESOLVED_VERSION}_${TS_ARCH}.tgz"
          else
            URL="https://pkgs.tailscale.com/unstable/tailscale_${RESOLVED_VERSION}_${TS_ARCH}.tgz"
          fi
          echo "Downloading $URL"
          curl -H user-agent:tailscale-github-action -L "$URL" -o tailscale.tgz --max-time 300 --retry 3 --retry-all-errors --fail
          echo "Expected sha256: $SHA256SUM"
          echo "Actual sha256: $(sha256sum tailscale.tgz)"
          echo "$SHA256SUM  tailscale.tgz" | sha256sum -c

      - name: Save Tailscale Binary - Linux
        if: ${{ inputs.use-cache == 'true' && steps.restore-cache-tailscale-linux.outputs.cache-hit != 'true' && runner.os == 'Linux' }}
        uses: actions/cache/save@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
        id: save-cache-tailscale-linux
        with:
          path: tailscale.tgz
          key: ${{ runner.os }}-tailscale-${{ env.RESOLVED_VERSION }}-${{ env.TS_ARCH }}-${{ env.SHA256SUM }}
      
      - name: Install Tailscale - Linux
        if: ${{ runner.os == 'Linux' }}
        shell: bash
        run: |
          tar -C /tmp -xzf tailscale.tgz
          rm tailscale.tgz
          TSPATH=/tmp/tailscale_${RESOLVED_VERSION}_${TS_ARCH}
          sudo mv "${TSPATH}/tailscale" "${TSPATH}/tailscaled" /usr/bin

      - name: Set SHA256 - Windows
        if: ${{ runner.os == 'Windows' }}
        shell: bash
        run: |
          MINOR=$(echo "$RESOLVED_VERSION" | awk -F '.' {'print $2'})
          if [ $((MINOR % 2)) -eq 0 ]; then
            URL="https://pkgs.tailscale.com/stable/tailscale-setup-${RESOLVED_VERSION}-${TS_ARCH}.msi.sha256"
          else
            URL="https://pkgs.tailscale.com/unstable/tailscale-setup-${RESOLVED_VERSION}-${TS_ARCH}.msi.sha256"
          fi
          
          if [[ "${{ inputs.sha256sum }}" ]]; then
            SHA256SUM="${{ inputs.sha256sum }}"
          else
            SHA256SUM="$(curl -H user-agent:tailscale-github-action -L "${URL}" --fail)"
          fi
          echo "SHA256SUM=$SHA256SUM" >> $GITHUB_ENV

      - name: Restore Tailscale Binary - Windows
        if: ${{ inputs.use-cache == 'true' && runner.os == 'Windows' }}
        uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
        id: restore-cache-tailscale-windows
        with:
          path: tailscale.msi
          key: ${{ runner.os }}-tailscale-${{ env.RESOLVED_VERSION }}-${{ env.TS_ARCH }}-${{ env.SHA256SUM }}

      - name: Download Tailscale - Windows
        if: ${{ runner.os == 'Windows' && (inputs.use-cache != 'true' || steps.restore-cache-tailscale-windows.outputs.cache-hit != 'true') }}
        shell: bash
        run: |
          MINOR=$(echo "$RESOLVED_VERSION" | awk -F '.' {'print $2'})
          if [ $((MINOR % 2)) -eq 0 ]; then
            URL="https://pkgs.tailscale.com/stable/tailscale-setup-${RESOLVED_VERSION}-${TS_ARCH}.msi"
          else
            URL="https://pkgs.tailscale.com/unstable/tailscale-setup-${RESOLVED_VERSION}-${TS_ARCH}.msi"
          fi
          echo "Downloading $URL"
          curl -H user-agent:tailscale-github-action -L "$URL" -o tailscale.msi --max-time 300 --retry 3 --retry-all-errors --fail
          echo "Expected sha256: $SHA256SUM"
          echo "Actual sha256: $(sha256sum tailscale.msi)"
          echo "$SHA256SUM  tailscale.msi" | sha256sum -c

      - name: Save Tailscale Binary - Windows
        if: ${{ inputs.use-cache == 'true' && steps.restore-cache-tailscale-windows.outputs.cache-hit != 'true' && runner.os == 'Windows' }}
        uses: actions/cache/save@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
        id: save-cache-tailscale-windows
        with:
          path: tailscale.msi
          key: ${{ runner.os }}-tailscale-${{ env.RESOLVED_VERSION }}-${{ env.TS_ARCH }}-${{ env.SHA256SUM }}

      - name: Install Tailscale - Windows
        if: ${{ runner.os == 'Windows' }}
        shell: pwsh
        run: |
          Start-Process "C:\Windows\System32\msiexec.exe" -Wait -ArgumentList @('/quiet', '/l*v ${{ runner.temp }}/tailscale.log', '/i', 'tailscale.msi')
          Add-Content $env:GITHUB_PATH "C:\Program Files\Tailscale\"
          Remove-Item tailscale.msi -Force;
      - name: Checkout Tailscale repo - macOS
        id: checkout-tailscale-macos
        if: ${{ runner.os == 'macOS' }}
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          repository: tailscale/tailscale
          path: ${{ github.workspace }}/tailscale
          ref: v${{ env.RESOLVED_VERSION }}
      - name: Restore Tailscale - macOS
        if: ${{ inputs.use-cache == 'true' && runner.os == 'macOS' }}
        id: restore-cache-tailscale-macos
        uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
        with:
          path: |
            /usr/local/bin/tailscale
            /usr/local/bin/tailscaled
          key: ${{ runner.os }}-tailscale-${{ env.RESOLVED_VERSION }}-${{ runner.arch }}-${{ steps.checkout-tailscale-macos.outputs.commit }}
      - name: Build Tailscale binaries - macOS
        if: ${{ runner.os == 'macOS' && (inputs.use-cache != 'true' || steps.restore-cache-tailscale-macos.outputs.cache-hit != 'true') }}
        shell: bash
        run: |
          cd tailscale
          export TS_USE_TOOLCHAIN=1
          ./build_dist.sh ./cmd/tailscale
          ./build_dist.sh ./cmd/tailscaled
          sudo mv tailscale tailscaled /usr/local/bin
      - name: Remove tailscale checkout - macOS
        if: ${{ runner.os == 'macOS' }}
        shell: bash
        run: |
          rm -Rf ${{ github.workspace }}/tailscale
      - name: Save Tailscale - macOS
        if: ${{ inputs.use-cache == 'true' && runner.os == 'macOS' }}
        id: save-cache-tailscale-macos
        uses: actions/cache/save@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
        with:
          path: |
            /usr/local/bin/tailscale
            /usr/local/bin/tailscaled
          key: ${{ runner.os }}-tailscale-${{ env.RESOLVED_VERSION }}-${{ runner.arch }}-${{ steps.checkout-tailscale-macos.outputs.commit }}
      - name: Install timeout - macOS
        if: ${{ runner.os == 'macOS' }}
        shell: bash
        run:
          brew install coreutils  # for 'timeout'
      - name: Start Tailscale Daemon - non-Windows
        if: ${{ runner.os != 'Windows' }}
        shell: bash
        env:
          ADDITIONAL_DAEMON_ARGS: ${{ inputs.tailscaled-args }}
          STATEDIR: ${{ inputs.statedir }}
        run: |
          if [ "$STATEDIR" == "" ]; then
            STATE_ARGS="--state=mem:"
          else
            STATE_ARGS="--statedir=${STATEDIR}"
            mkdir -p "$STATEDIR"
          fi
          sudo -E tailscaled ${STATE_ARGS} ${ADDITIONAL_DAEMON_ARGS} 2>~/tailscaled.log &
          # And check that tailscaled came up. The CLI will block for a bit waiting
          # for it. And --json will make it exit with status 0 even if we're logged
          # out (as we will be). Without --json it returns an error if we're not up.
          sudo -E tailscale status --json >/dev/null
      - name: Connect to Tailscale
        shell: bash
        env:
          ADDITIONAL_ARGS: ${{ inputs.args }}
          HOSTNAME: ${{ inputs.hostname }}
          TAILSCALE_AUTHKEY: ${{ inputs.authkey }}
          TIMEOUT: ${{ inputs.timeout }}
          RETRY: ${{ inputs.retry }}
        run: |
          sanitize_hostname() {
            local hostname="$1"
            hostname=$(echo "$hostname" | sed 's/[^a-zA-Z0-9-]/-/g') # Replace invalid characters with dashes
            hostname=$(echo "$hostname" | cut -c1-63) # Truncate to 63 characters maximum
            hostname=$(echo "$hostname" | sed 's/^-*//;s/-*$//') # Remove leading/trailing dashes
            echo "$hostname"
          }

          is_valid_dns_label() {
            local hostname="$1"
            if [ ${#hostname} -eq 0 ] || [ ${#hostname} -gt 63 ]; then # Check length (1-63 characters)
              return 1
            fi
            if ! echo "$hostname" | grep -qE '^[a-zA-Z0-9-]+$'; then # Check for valid characters (alphanumeric and dashes only)
              return 1
            fi
            if echo "$hostname" | grep -qE '^-|-$'; then # Check that it doesn't start or end with dash
              return 1
            fi
            return 0
          }

          if [ -z "${HOSTNAME}" ]; then
            if [ "${{ runner.os }}" == "Windows" ]; then
              HOSTNAME="github-$COMPUTERNAME"
            else
              HOSTNAME="github-$(hostname)"
            fi
            HOSTNAME=$(sanitize_hostname "$HOSTNAME")
          else
            if ! is_valid_dns_label "$HOSTNAME"; then
              echo "::error::HOSTNAME '$HOSTNAME' is not a valid DNS label. It should contain only alphanumeric characters and dashes, be 1-63 characters long, and not start or end with a dash."
              exit 1
            fi
          fi

          if [ -n "${{ inputs['oauth-secret'] }}" ]; then
            TAILSCALE_AUTHKEY="${{ inputs['oauth-secret'] }}?preauthorized=true&ephemeral=true"
            TAGS_ARG="--advertise-tags=${{ inputs.tags }}"
          fi
          if [ "${{ runner.os }}" != "Windows" ]; then
            MAYBE_SUDO="sudo -E"
          fi
          if [ "${{ runner.os }}" == "Windows" ]; then
            PLATFORM_SPECIFIC_ARGS="--unattended"
          fi
          for ((i=1;i<=$RETRY;i++)); do
            echo "Attempt $i to bring up Tailscale..."
            timeout --verbose --kill-after=1s ${TIMEOUT} ${MAYBE_SUDO} tailscale up ${TAGS_ARG} --authkey=${TAILSCALE_AUTHKEY} --hostname=${HOSTNAME} --accept-routes ${PLATFORM_SPECIFIC_ARGS} ${ADDITIONAL_ARGS} && break
            echo "Tailscale up failed. Retrying in $((i * 5)) seconds..."
            sleep $((i * 5))
          done
      - name: Verify Target Connectivity
        if: ${{ inputs.targets != '' }}
        shell: bash
        env:
          TARGETS: ${{ inputs.targets }}
        run: |
          IFS=',' read -ra TARGET_ARRAY <<< "$TARGETS"

          if [ "${{ runner.os }}" != "Windows" ]; then
            MAYBE_SUDO="sudo -E"
          fi

          failed_targets=()
          for target in "${TARGET_ARRAY[@]}"; do
            target=$(echo "$target" | xargs)  # trim whitespace
            if [ -n "$target" ]; then
              output=$(${MAYBE_SUDO} tailscale ping --c=36 $target 2>&1)
              exit_code=$?

              if [ $exit_code -eq 0 ]; then
                echo "Successfully reached $target"
              elif echo "$output" | grep -q "direct connection not established"; then
                echo "::warning title=Target Connectivity Warning::Failed to establish direct connection to $target but was able to connect via DERP"
              else
                # Regular failure case
                echo "Failed to reach $target"
                failed_targets+=("$target")
              fi
            fi
          done

          if [ ${#failed_targets[@]} -gt 0 ]; then
            echo "::error title=Target Connectivity Failed::Failed to reach the following targets: ${failed_targets[*]}"
            exit 1
          fi