# notify-image-updater

Composite action that POSTs a CloudEvents v1.0 payload to the in-cluster
`argocd-image-updater` webhook so it reconciles the matching `ImageUpdater`
CR immediately instead of waiting for the next 30s poll tick.

Pair it with `docker/build-push-action` (or any step that publishes an
image and exposes a `digest` output).

## Usage

```yaml
jobs:
  build:
    runs-on: aceofba-cluster
    container:
      image: ghcr.io/catthehacker/ubuntu:act-22.04
    env:
      IMAGE_UPDATER_WEBHOOK_SECRET: ${{ secrets.IMAGE_UPDATER_WEBHOOK_SECRET }}
    steps:
      - uses: actions/checkout@v4

      - uses: https://git.aceofba.se/infra/setup-buildx@v1

      - uses: docker/login-action@v3
        with:
          registry: git.aceofba.se
          username: ${{ gitea.actor }}
          password: ${{ secrets.GITEA_TOKEN }}

      - id: meta
        uses: docker/metadata-action@v5
        with:
          images: git.aceofba.se/${{ gitea.repository }}
          tags: |
            type=sha,prefix=,format=short
            type=raw,value=latest,enable={{is_default_branch}}

      - id: build
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - uses: https://git.aceofba.se/infra/notify-image-updater@v1
        with:
          image: git.aceofba.se/${{ gitea.repository }}
          tag: ${{ steps.meta.outputs.version }}
          digest: ${{ steps.build.outputs.digest }}
```

## Inputs

| Name | Required | Default | Description |
|------|----------|---------|-------------|
| `image` | yes | – | Fully-prefixed image repository, e.g. `git.aceofba.se/owner/repo`. Must match `data.repositoryName` matching in argocd-image-updater's registry config. |
| `tag` | yes | – | Tag that was just pushed. |
| `digest` | yes | – | Image digest. Use `${{ steps.<build-id>.outputs.digest }}` from `docker/build-push-action`. |
| `secret` | no | `${{ env.IMAGE_UPDATER_WEBHOOK_SECRET }}` | CloudEvents shared secret. Read by default from the `IMAGE_UPDATER_WEBHOOK_SECRET` env var (set it from a repo or org Gitea Actions secret). |
| `webhook-url` | no | `http://argocd-image-updater.argocd.svc.cluster.local:8080/webhook` | Webhook endpoint. Only override for non-default clusters. |

## Setting up the secret

Add an org-level Gitea Actions secret named `IMAGE_UPDATER_WEBHOOK_SECRET`
with the value from
`infra/clusters` → `base/argo-cd-image-updater/manifests/webhook-secret.yaml`
(`stringData.CLOUDEVENTS_WEBHOOK_SECRET`). Repos that build images then
just expose it via `env:` at the job level.

## Why

The controller polls every 30s by default — fine for most cases but slow
when iterating. With a webhook hit at the end of the build, the
ImageUpdater controller reconciles immediately, finds the new tag, and
pushes the manifest bump. Combined with a Gitea→Argo CD repo webhook, the
end-to-end CI-to-deploy latency drops from minutes to seconds.

## Notes

- The cluster's argocd-image-updater service is ClusterIP-only; this
  action only works from in-cluster runners (which is what
  `aceofba-cluster` is).
- A non-2xx response fails the step. Argo CD reconciliation latency
  itself is not part of this action — once the manifest commit lands,
  Argo CD picks it up via its own webhook from Gitea.