Add tests for pre-commit container

Run pre-commit on the freshly built container against salt and rc2matrix

.woodpecker/.build.yaml

@@ -1,8 +1,10 @@
+when:
+  path: '*Dockerfile*'
+
 steps:
   build main:
     when:
-      - event: push
-        branch: main
+      branch: main
     image: woodpeckerci/plugin-docker-buildx:4.0.0@sha256:9d24b71c37d7a958d79252e608c4d1a04b02f2e74d4e26003b43e0830038bde0
     pull: true
     settings:
@@ -18,9 +20,8 @@ steps:
 
   build branch:
     when:
-      - event: push
-        branch:
-          exclude: ['main']
+      branch:
+        exclude: ['main']
     image: woodpeckerci/plugin-docker-buildx:4.0.0@sha256:9d24b71c37d7a958d79252e608c4d1a04b02f2e74d4e26003b43e0830038bde0
     pull: true
     settings:

README.md

@@ -22,52 +22,10 @@ steps:
       - pre-commit run --all-files
 ```
 
-If renovate is set up for your repo, it'll add and update the pinned digest/hash of the image.
+If renovate is set up, it'll add and update the pinned digest/hash of the image.
 
 ## Development
 
-Generally you should have `Docker` or something alike installed.
-
 If you need to copy files into the container, don't forget to add exclusions to the general _exclude all_ in `.dockerignore`.
 
-To **update the base image** (like `3.12.4-alpine3.20` to a newer Alpine version), manual work is still required, but supported by a little script. **Renovate might not create a PR for newer image tags.**
-
-1. In the `Dockerfile`, update the Alpine version for the image and the renovate comments (`# renovate: datasource=repology depName=alpine_3_20/gcc versioning=loose`).
-
-   ```diff
-   - FROM python:3-alpine3.19@sha256:00c0ffeeacab...
-   + FROM python:3-alpine3.20 # You can omit the sha256 digest, the script prints it out
-   # ...
-
-   - # renovate: datasource=repology depName=alpine_3_19/build-base versioning=loose
-   + # renovate: datasource=repology depName=alpine_3_20/build-base versioning=loose
-   ENV BUILD_BASE_VERSION="0.8.15"
-   # ...
-   ```
-
-1. Now run `./get_pkg_versions.sh`. It pulls the alpine image from the Dockerfile, prints it's digest and the latest packages it could find via `apk` inside that container and prints out the names and versions.
-
-   Example output of `./get_pkg_versions.sh` for a new image, which is not yet pulled:
-
-   ```plain
-   Unable to find image 'python:3.12.3-alpine3.18' locally
-   3.12.3-alpine3.18: Pulling from library/python
-   619be1103602: Pull complete
-     [...]
-   0eb61f1af52e: Pull complete
-   Digest: sha256:24680ddf8422899b24756d62b31eb5de782fbb42e9c2bb1c70f1f55fcf891721
-   Status: Downloaded newer image for python:3.12.3-alpine3.18
-     [Script output starts here]
-   Checking 5/5 latest package versions on python:3.12.3-alpine3.18
-   Image digest found: sha256:24680ddf8422899b24756d62b31eb5de782fbb42e9c2bb1c70f1f55fcf891721
-   ---
-   build-base-0.5-r3
-   gcc-12.2.1_git20220924-r10
-   git-2.40.1-r0
-   openssh-keygen-9.3_p2-r1
-   ruby-3.2.4-r0
-   ```
-
-1. Copy the package versions and update the respective `ENV` with it manually in the `Dockerfile`. You also might add the digest to the base image.
-
-1. Test building the image and you can commit it.
+To update the base image (like `3.12.4-alpine3.20` to a newer Alpine version), manual work is still required. In the `Dockerfile`, update the Alpine version for the image, the renovate comments (`# renovate: datasource=repology depName=alpine_3_20/gcc versioning=loose`), and the package versions for that OS version from the repo (Like on the [Alpine Package Page for gcc](https://pkgs.alpinelinux.org/packages?name=gcc&branch=v3.20&repo=&arch=x86_64)).

get_pkg_versions.sh

@@ -1,15 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-IFS=$'\n\t'
-
-IMAGE=$(grep -oP 'FROM \K.*alpine[^ ]+' Dockerfile)
-PACKAGES=$(grep -oP '#.+depName=alpine.+/\K[^ ]+' Dockerfile)
-# shellcheck disable=SC2086
-PACKAGES_NO_BR=$(echo ${PACKAGES} | tr -d '\n')
-PACKAGES_VERSIONS=$(docker run --rm -t --entrypoint /bin/sh "$IMAGE" -c "apk --update --no-cache list $PACKAGES_NO_BR | cut -d ' ' -f 1 | grep -v '^fetch$'")
-DIGEST=$(docker inspect --format='{{index .RepoDigests 0}}' "$IMAGE" | cut -d '@' -f2)
-
-echo "Checking $(echo "$PACKAGES" | wc -l)/$(echo "$PACKAGES_VERSIONS" | wc -l) latest package versions on $IMAGE"
-echo "Image digest found: $DIGEST"
-echo "---"
-echo "$PACKAGES_VERSIONS"