README.md

Scan Docker Tags Action

Scans the Microsoft Container Registry for images and tags. This allows you to build new images based on Microsoft's docker images on a regular basis.

Inspired by the scan-docker-tags-action.

Example

This example workflow scans for dotnet/sdk images with tags that match the last 3 major versions and all of their minor versions every Monday at 6 AM. The output is picked up in another build step that prints each image and tag with the matrix strategy.

name: Scan Images
on:
  schedule:
    - cron: '0 6 * * 1'

jobs:
  scan:
    name: List Recent Updates
    runs-on: ubuntu-latest
    outputs: 
      images: ${{ steps.scan.outputs.images }}
    steps:
      - name: Checkout
        uses: actions/checkout@v2
      - name: Scan Docker Repository
        uses: divinebovine/[email protected]
        with:
          image: dotnet/sdk
          tag-regex: ^\d+\.\d+-(alpine|focal)$
          version-limit: 3
        id: scan
  build:
    needs: scan
    runs-on: ubuntu-latest
    strategy:
      matrix:
        image: ${{ fromJson(needs.scan.outputs.images) }}
    steps:
      - name: Test
        run : echo dotnet:${{matrix.image}}

Required Inputs

Parameter	Description
images	The image or an array of images to scan (sans tag), e.g. dotnet/sdk, ["dotnet/sdk", "dotnet/aspnet"].

Optional Inputs

Parameter	Description	Default
tag-regex	A regular expression for filtering tags. E.g. \d+\.\d+$ matches 0.10, 1.2, 1.12.123, etc.	.*
repo-url	The URL of the Docker registry.	https://mcr.microsoft.com
version-limit	The number of major versions, starting from the latest, to limit the results.	'*' which includes every tag

Outputs

The only output this action exposes is the images output. images is a comma-separated list of all image tags that match the regular expression and are limited by the version limit.