variables.sh

#!/bin/bash
set -o errexit #abort if any command fails
me=$(basename "$0")

help_message="\
Usage: echo $me <version>

Generates variables based on the provided environment variable GITHUB_CONTEXT
and <version> argument.

GITHUB_CONTEXT: An environment variable containing a JSON string of the GitHub
                context object. Typically generated with \${{ toJson(github) }}.
     <version>: The version number corresponding to the current Git commit."

initialize() {
    github_context_json="$GITHUB_CONTEXT"
    version="$1"

    if [[ -z "$github_context_json" ]]; then
        echo "Missing or empty GITHUB_CONTEXT environment variable." >&2
        echo "$help_message"
        exit 1
    fi

    if [[ -z "$version" ]]; then
        echo "No version specified." >&2
        echo "$help_message"
        exit 1
    fi

    sha=$(echo "$github_context_json" | jq --raw-output .sha)
    ref=$(echo "$github_context_json" | jq --raw-output .ref)
    run_id=$(echo "$github_context_json" | jq --raw-output .run_id)
    run_number=$(echo "$github_context_json" | jq --raw-output .run_number)

    if [[ -z "$sha" ]]; then
        echo "No 'sha' found in the GitHub context." >&2
        echo "$help_message"
        exit 1
    fi

    if [[ -z "$ref" ]]; then
        echo "No 'ref' found in the GitHub context." >&2
        echo "$help_message"
        exit 1
    fi

    if [[ -z "$run_id" ]]; then
        echo "No 'run_id' found in the GitHub context." >&2
        echo "$help_message"
        exit 1
    fi

    if [[ -z "$run_number" ]]; then
        echo "No 'run_number' found in the GitHub context." >&2
        echo "$help_message"
        exit 1
    fi
}

generate_variables() {
    # Replace + in the version number with a dot.
    version="${version/+/.}"
    sha8=$(echo "${sha}" | cut -c1-8)
    date=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
    ghpr_docker_image_name="docker.pkg.github.com/swedbankpay/jekyll-plantuml-docker/jekyll-plantuml"
    docker_hub_image_name="swedbankpay/jekyll-plantuml"

    if [[ "$ref" == refs/tags/* ]]; then
        # Override GitVersion's version on tags, just to be sure.
        version="${ref#refs/tags/}"
        docker_image_name="$docker_hub_image_name"
        docker_image_tag="$version"
    else
        docker_image_name="$ghpr_docker_image_name"
        docker_image_tag="$sha8"
    fi

    docker_image_fqn="$docker_image_name:$docker_image_tag"
    ghpr_docker_image_fqn="$ghpr_docker_image_name:$sha8"
    docker_hub_image_name="$docker_hub_image_name:$version"
    deploy_branch="r${run_id}-${run_number}"
    build_branch="${ref#refs/tags/}"
    build_branch="${build_branch#refs/heads/}"

    echo "Ref:                $ref"
    echo "Sha:                $sha"
    echo "Sha8:               $sha8"
    echo "Date:               $date"
    echo "Build Branch:       $build_branch"
    echo "Deploy Branch:      $deploy_branch"
    echo "Version:            $version"
    echo "Docker Image Name:  $docker_image_name"
    echo "Docker Image Tag:   $docker_image_tag"
    echo "Docker Image FQN:   $docker_image_fqn"
    echo "::set-output name=ref::$ref"
    echo "::set-output name=sha::$sha"
    echo "::set-output name=sha8::$sha8"
    echo "::set-output name=date::$date"
    echo "::set-output name=version::$version"
    echo "::set-output name=build_branch::$build_branch"
    echo "::set-output name=deploy_branch::$deploy_branch"
    echo "::set-output name=docker_image_name::$docker_image_name"
    echo "::set-output name=docker_image_tag::$docker_image_tag"
    echo "::set-output name=docker_image_fqn::$docker_image_fqn"
    echo "::set-output name=ghpr_docker_image_fqn::$ghpr_docker_image_fqn"
}

main() {
    initialize "$@"
    generate_variables
}

main "$@"