action.yml

name: Update devcontainer version
description: "Updates the devcontainer version in devcontainer.json."
inputs:
  calling_repo_base_branch:
    description: "The base branch from the calling repository that should be merged into"
    required: false
    default: main
  CREATE_PULL_REQUEST_APP_ID:
    description: "GitHub App ID for creating pull requests"
    required: true
  CREATE_PULL_REQUEST_PEM:
    description: "Private key for the GitHub App in PEM format"
    required: true
runs:
  using: "composite"
  steps:
    - name: Checkout calling repo code
      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
      with:
        ref: ${{ inputs.calling_repo_base_branch }}
        fetch-depth: 0
        persist-credentials: false

    - name: Load config value
      shell: bash
      id: load-config
      run: |
        set -euo pipefail
        DEVCONTAINER_IMAGE=$(jq -r '.build.args.IMAGE_NAME' .devcontainer/devcontainer.json)

        DEVCONTAINER_VERSION=$(jq -r '.build.args.IMAGE_VERSION' .devcontainer/devcontainer.json)

        {
          echo "DEVCONTAINER_IMAGE=$DEVCONTAINER_IMAGE"
          echo "DEVCONTAINER_VERSION=$DEVCONTAINER_VERSION"
        } >> "$GITHUB_OUTPUT"

    - name: Resolve latest devcontainer image version from GHCR
      shell: bash
      id: resolve-version
      env:
        GH_TOKEN: "${{ github.token }}"
        DEVCONTAINER_IMAGE: "${{ steps.load-config.outputs.DEVCONTAINER_IMAGE }}"
        DEVCONTAINER_VERSION: "${{ steps.load-config.outputs.DEVCONTAINER_VERSION }}"
      run: |
        set -euo pipefail

        PACKAGE_NAME="eps-devcontainers/${DEVCONTAINER_IMAGE}"
        ENCODED_PACKAGE_NAME=$(python3 -c 'import sys, urllib.parse; print(urllib.parse.quote(sys.argv[1], safe=""))' "$PACKAGE_NAME")
        VERSIONS_JSON=$(gh api \
          -H "Accept: application/vnd.github+json" \
          "/orgs/NHSDigital/packages/container/${ENCODED_PACKAGE_NAME}/versions?per_page=100")
        LATEST_VIA_LATEST_TAG=$(jq -r '
          [ .[]
            | select((.metadata.container.tags // []) | index("latest"))
          ]
          | sort_by(.created_at)
          | reverse
          | .[0].metadata.container.tags // []
          | map(select(test("^v")))
          | .[0] // empty
        ' <<< "$VERSIONS_JSON")

        LATEST_V_TAG=$(jq -r '
          [ .[]
            | {created_at, tags: (.metadata.container.tags // [])}
          ]
          | sort_by(.created_at)
          | reverse
          | map(.tags[]? | select(test("^v")))
          | .[0] // empty
        ' <<< "$VERSIONS_JSON")

        RESOLVED_VERSION="$LATEST_VIA_LATEST_TAG"

        if [[ -z "$RESOLVED_VERSION" ]]; then
          RESOLVED_VERSION="$LATEST_V_TAG"
        fi

        if [[ -z "$RESOLVED_VERSION" ]]; then
          echo "No version tag matching ^v found for package ${PACKAGE_NAME}" >&2
          exit 1
        fi

        echo "Resolved latest version: ${RESOLVED_VERSION}"
        echo "latest_version=${RESOLVED_VERSION}" >> "$GITHUB_OUTPUT"

    - name: Update devcontainer version in config
      shell: bash
      run: |
        set -euo pipefail

        if [[ "$LATEST_DEVCONTAINER_VERSION" == "$DEVCONTAINER_VERSION" ]]; then
          echo "IMAGE_VERSION is already up to date (${DEVCONTAINER_VERSION})"
          exit 0
        fi

        python3 - <<'PY'
        import json
        import os
        from pathlib import Path
        config_file = Path('.devcontainer/devcontainer.json')
        config = json.loads(config_file.read_text())
        config['build']['args']['IMAGE_VERSION'] = os.environ['LATEST_DEVCONTAINER_VERSION']
        config_file.write_text(json.dumps(config, indent=2) + '\n')
        PY

        echo "Updated IMAGE_VERSION from ${DEVCONTAINER_VERSION} to ${LATEST_DEVCONTAINER_VERSION}"
      env:
        LATEST_DEVCONTAINER_VERSION: "${{ steps.resolve-version.outputs.latest_version }}"
        DEVCONTAINER_VERSION: "${{ steps.load-config.outputs.DEVCONTAINER_VERSION }}"

    - name: Create GitHub App Token
      uses: actions/create-github-app-token@f8d387b68d61c58ab83c6c016672934102569859
      id: generate-token
      with:
        app-id: "${{ inputs.CREATE_PULL_REQUEST_APP_ID }}"
        private-key: "${{ inputs.CREATE_PULL_REQUEST_PEM }}"

    - name: Create Pull Request
      uses: peter-evans/create-pull-request@5f6978faf089d4d20b00c7766989d076bb2fc7f1
      with:
        token: "${{ steps.generate-token.outputs.token }}"
        commit-message: Update devcontainer image version to ${{ steps.resolve-version.outputs.latest_version }}
        title: "Upgrade: [dependabot] - update devcontainer image version to ${{ steps.resolve-version.outputs.latest_version }}"
        body: |
          Updating devcontainer image version to ${{ steps.resolve-version.outputs.latest_version }}.
        branch: devcontainer-image-update
        base: ${{ inputs.calling_repo_base_branch }}
        branch-suffix: random
        sign-commits: true
        delete-branch: true