denhamparry/digestabot

Github Action to automatically update digests for container images.

Image Digest Update (digestabot)

This action updates a image digest when using the tag+digest pattern. If the tag is mutable it will have a new digest when the tag is updated. If there is a change in the digest this action will update to the latest digest and open a PR.

Given an image in the format <repo>:<tag>@sha256:<digest> e.g. cgr.dev/chainguard/nginx:latest@sha256:81bed54c9e507503766c0f8f030f869705dae486f37c2a003bb5b12bcfcc713f, digesta-bot will look up the digest of the tag on the registry and, if it doesn't match, open a PR to update it. This can be used to keep tags up-to-date whilst maintaining a reproducible build and providing an opportunity to test updates.

Usage

Basic usage:

    - uses: chainguard-dev/digestabot@v1.0.2
        with:
          token: ${{ secrets.GITHUB_TOKEN }}

Scenarios

name: Image digest update

on:
  workflow_dispatch:
  schedule:
    # At the end of every day
    - cron: "0 0 * * *"

jobs:
  image-update:
    name: Image digest update
    runs-on: ubuntu-latest

    permissions:
      contents: write # to push the updates
      pull-requests: write # to open Pull requests
      id-token: write # used to sign the commits using gitsign

    steps:
    - uses: actions/checkout@v4
    - uses: chainguard-dev/digestabot@v1.0.2
      with:
        token: ${{ secrets.GITHUB_TOKEN }}
        signoff: true # optional
        author: update-bot # optional
        committer: update-bot@example.com # optional
        labels-for-pr: automated pr, kind/cleanup, release-note-none # optional
        branch-for-pr: update-digests # optional
        title-for-pr: Update images digests # optional
        commit-message: Update images digests # optional

File examples

Here are some examples of files that digestabot can update:

• .ko.yaml:

defaultBaseImage: cgr.dev/chainguard/kubectl:latest-dev@sha256:d5f340d044438351413d6cb110f6f8a2abc45a7149aa53e6ade719f069fc3b0a

• any Kubernetes manifest with an image field e.g: Job:

apiVersion: batch/v1
kind: Job
metadata:
  namespace: default
  name: myjob
spec:
  template:
    spec:
      restartPolicy: Never
      initContainers:
      - image: cgr.dev/chainguard/cosign:latest-dev@sha256:09653ac03c1ac1502c3e3a8831ee79252414e4d659b423b71fb7ed8b097e9c88
...

• Dockerfile:

FROM cgr.dev/chainguard/busybox:latest@sha256:257157f6c6aa88dd934dcf6c2f140e42c2653207302788c0ed3bebb91c5311e1

• Kustomizations:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - "https://github.com/cert-manager/cert-manager/releases/download/v1.11.1/cert-manager.yaml"
patchesJSON6902:
  - target:
      group: apps
      version: v1
      kind: Deployment
      name: cert-manager
    patch: |-
      - op: replace
        path: /spec/template/spec/containers/0/image
        value: cgr.dev/chainguard/cert-manager-controller:1.11.1@sha256:819a8714fc52fe3ecf3d046ba142e02ce2a95d1431b7047b358d23df6759de6c
...