Add GitHub workflow to auto update (rebuild & publish) containers

Author: PhrozenByte

.github/workflows/container-auto-update.yml

@@ -0,0 +1,73 @@
+name: Periodically rebuild & publish containers (auto update)
+
+on:
+  schedule:
+    # run once a day at 21:50 UTC
+    - cron: '50 21 * * *'
+
+concurrency: build
+
+env:
+  CI_TOOLS_SETUP: https://raw.githubusercontent.com/SGSGermany/ci-tools/main/setup.sh
+
+defaults:
+  run:
+    shell: bash -eu -o pipefail {0}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    env:
+      REGISTRY: ghcr.io
+      OWNER: sgsgermany
+      IMAGE: butane
+
+    steps:
+      - name: Setup CI tools
+        run: |
+          . <(curl -fsS -L "$CI_TOOLS_SETUP" | bash -s ~/ci-tools)
+          echo "CI_TOOLS=$CI_TOOLS" | tee -a "$GITHUB_ENV"
+          echo "CI_TOOLS_PATH=$CI_TOOLS_PATH" | tee -a "$GITHUB_ENV"
+
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Log into container registry ${{ env.REGISTRY }}
+        uses: redhat-actions/podman-login@v1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Generate container image tags
+        run: |
+          source <(./tags.sh "$GITHUB_RUN_ID.$GITHUB_RUN_NUMBER")
+          echo "MILESTONE=$MILESTONE" | tee -a "$GITHUB_ENV"
+          echo "VERSION=$VERSION" | tee -a "$GITHUB_ENV"
+          echo "TAGS=$TAGS" | tee -a "$GITHUB_ENV"
+
+      - name: Check for updates
+        run: |
+          BUILD_ACTION="$(./check-for-updates.sh)"
+          echo "BUILD_ACTION=$BUILD_ACTION" | tee -a "$GITHUB_ENV"
+
+      - name: Build container image
+        if: ${{ env.BUILD_ACTION != '' }}
+        run: |
+          buildah unshare ./build.sh
+
+      - name: Container image metadata
+        run: |
+          "$CI_TOOLS_PATH/containers/get-metadata.sh" "$REGISTRY/$OWNER" "$IMAGE:${TAGS%% *}"
+
+      - name: Push container image
+        if: ${{ env.BUILD_ACTION != '' }}
+        uses: redhat-actions/push-to-registry@v2
+        with:
+          image: ${{ env.IMAGE }}
+          registry: ${{ env.REGISTRY }}/${{ env.OWNER }}
+          tags: ${{ env.TAGS }}

check-for-updates.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+# Unbound
+# A container running Butane, a config translator for FCOS' Ignition.
+#
+# Copyright (c) 2025  SGS Serious Gaming & Simulations GmbH
+#
+# This work is licensed under the terms of the MIT license.
+# For a copy, see LICENSE file or <https://opensource.org/licenses/MIT>.
+#
+# SPDX-License-Identifier: MIT
+# License-Filename: LICENSE
+
+set -eu -o pipefail
+export LC_ALL=C.UTF-8
+
+[ -v CI_TOOLS ] && [ "$CI_TOOLS" == "SGSGermany" ] \
+    || { echo "Invalid build environment: Environment variable 'CI_TOOLS' not set or invalid" >&2; exit 1; }
+
+[ -v CI_TOOLS_PATH ] && [ -d "$CI_TOOLS_PATH" ] \
+    || { echo "Invalid build environment: Environment variable 'CI_TOOLS_PATH' not set or invalid" >&2; exit 1; }
+
+source "$CI_TOOLS_PATH/helper/common.sh.inc"
+source "$CI_TOOLS_PATH/helper/chkupd.sh.inc"
+source "$CI_TOOLS_PATH/helper/github.sh.inc"
+
+BUILD_DIR="$(CDPATH= cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
+source "$BUILD_DIR/container.env"
+
+TAG="${TAGS%% *}"
+
+# check whether the base image was updated
+chkupd_baseimage "$REGISTRY/$OWNER/$IMAGE" "$TAG" || exit 0
+
+# check whether a different Git tag was marked as latest GitHub release
+GITHUB_REPO_IDENT="${BUTANE_GIT_REPO#https://github.com/}"
+GITHUB_LATEST_VERSION="$(github_latest "$GITHUB_REPO_IDENT")"
+
+chkupd_image_version "$REGISTRY/$OWNER/$IMAGE:$TAG" \
+    "${GITHUB_LATEST_VERSION#v}" \
+    || exit 0