name: "Docker Check Base Image Diff"
description: "A Github Action that checks whether a derived image does not consist of a base image."
author: Clement Tsang <ClementTsang>
branding:
  icon: box
  color: blue

inputs:
  base-image:
    description: "Base Docker image - follows skopeo format (e.g. docker://rust:slim-buster)"
    required: true
  derived-image:
    description: "Derived Docker image - follows skopeo format (e.g. docker://rust:slim-buster)"
    required: true
outputs:
  differs:
    description: "Returns either true or false"
    value: ${{ steps.check.outputs.differs }}

runs:
  using: "composite"
  steps:
    - id: check
      shell: bash
      run: |
        RESULT=$(${{ github.action_path }}/check.sh ${{ inputs.base-image }} ${{ inputs.derived-image }})
        echo "::set-output name=differs::$RESULT"