python-repositories/docs/ci-image.md

# CI base image

This repository uses a **per-repo Docker image** for Gitea Actions jobs instead of
installing Python and `uv` on every run. Infrastructure images (redis, minio, etc.)
are cached cluster-wide via Harbor (see homelab-platform
[`docs/harbor-registry-mirror.md`](https://gitea.lille-vemmelund.dk/LilleVemmelund/homelab-platform/src/branch/main/docs/harbor-registry-mirror.md)).

## Image contents

Built from [`docker/ci/Dockerfile`](../docker/ci/Dockerfile):

- Node.js 20 (required by act_runner job containers)
- Python 3.12 (installed via `uv python install`) and pinned `uv` 0.7.0
- Docker CLI (integration tests via testcontainers)
- Dev dependencies from `uv.lock` (`uv sync --all-extras --no-install-project`)

Published to the Gitea container registry:

- `gitea.lille-vemmelund.dk/brian/python-repositories-ci:latest`
- `gitea.lille-vemmelund.dk/brian/python-repositories-ci:YYYYMMDDHHmm` (timestamped rollback tag)

## Rebuild triggers

[`ci-image.yml`](../.gitea/workflows/ci-image.yml) runs on:

- Nightly cron (`0 2 * * *` UTC)
- Manual `workflow_dispatch`
- Push to `main` when `pyproject.toml`, `uv.lock`, or `docker/ci/**` change

## Workflow usage

Python jobs use `runs-on: python-repositories-ci` and a fast incremental sync:

```yaml
runs-on: python-repositories-ci
steps:
  - uses: actions/checkout@v4
  - name: Sync dependencies
    env:
      UV_LINK_MODE: copy
      UV_INDEX_GITEA_USERNAME: ci-bot
      UV_INDEX_GITEA_PASSWORD: ${{ secrets.CI_RUNNER_TOKEN }}
    run: uv sync --all-extras --frozen
```

`ci-image.yml` uses `runs-on: ubuntu-latest` so it can bootstrap before the custom
image exists.

## Registry authentication

act_runner pulls the job image **before any workflow step runs**, so a `docker
login` step inside a job cannot authenticate that pull. Authentication must be
configured on the runner (or via a job-level `container.credentials` block — not
used here).

### k8s Gitea runners (automatic)

The homelab-platform runners mount Gitea registry credentials automatically:

- Secret: `gitea-runners/gitea-registry-dockerconfig` (created by
  [`scripts/create-gitea-registry-secret.sh`](https://gitea.lille-vemmelund.dk/LilleVemmelund/homelab-platform/src/branch/main/scripts/create-gitea-registry-secret.sh))
- Mounted at `/root/.docker/config.json` on the **runner** container (not DinD)
- Configured in
  [`platform/gitea-runners/values.yaml`](https://gitea.lille-vemmelund.dk/LilleVemmelund/homelab-platform/src/branch/main/platform/gitea-runners/values.yaml)

No manual `docker login` is required on the in-cluster runners once the secret
exists. To create or rotate credentials:

```bash
export KUBECONFIG=/path/to/homelab-cluster/talos/_out/kubeconfig
export GITEA_REGISTRY_USERNAME='ci-bot'
export GITEA_REGISTRY_PASSWORD='personal-access-token-with-read-package'
bash scripts/create-gitea-registry-secret.sh
```

Then restart runner pods so they pick up the updated secret. See homelab-platform
[`docs/gitea-actions-runners.md`](https://gitea.lille-vemmelund.dk/LilleVemmelund/homelab-platform/src/branch/main/docs/gitea-actions-runners.md)
for full runner setup.

Verify on a running pod:

```bash
kubectl -n gitea-runners exec homelab-cluster-gitea-runner-0 -c runner -- \
  test -f /root/.docker/config.json && echo "registry auth mounted"
```

### Standalone runners (e.g. Unraid `homelab`)

The 4th runner is outside the k8s cluster and does **not** get the automatic
mount. Configure registry auth manually on that host:

```bash
docker login gitea.lille-vemmelund.dk -u ci-bot -p <token>
```

Also add the `python-repositories-ci` label to that runner's act_runner config.

### `ci-image.yml` push login

The build workflow still runs `docker login` before `docker push`. That step
authenticates **DinD inside the job** for pushing the image to Gitea — a different
code path from act_runner pulling the job container.

## Runner label

Jobs use the `python-repositories-ci` act_runner label, configured in
homelab-platform
[`platform/gitea-runners/values.yaml`](https://gitea.lille-vemmelund.dk/LilleVemmelund/homelab-platform/src/branch/main/platform/gitea-runners/values.yaml):

```yaml
python-repositories-ci:docker://gitea.lille-vemmelund.dk/brian/python-repositories-ci:latest
```

After label changes, roll runner pods so they re-register with Gitea.

## Bootstrap order

1. Ensure homelab-platform runners have `gitea-registry-dockerconfig` and the
   `python-repositories-ci` label (see homelab-platform docs).
2. Merge `ci-image.yml`, `docker/ci/Dockerfile`, and workflow migrations to `main`.
3. Run **Build CI Image** manually once (Actions → Build CI Image → Run workflow).
4. Confirm a test workflow job starts on `python-repositories-ci`.

Until step 3 completes, jobs targeting `python-repositories-ci` will fail because
the image does not exist in the Gitea registry yet.

## Local build

```bash
echo "$CI_RUNNER_TOKEN" > /tmp/uv_token
docker build -f docker/ci/Dockerfile \
  --secret id=uv_token,src=/tmp/uv_token \
  -t python-repositories-ci:local .
rm -f /tmp/uv_token
```