* Add GitHub Action workflow to automatically (re)build the image

* Update Dockerfile to OCI specification

.github/workflows/docker-image.yaml

@@ -0,0 +1,81 @@
+#
+name: Docker Image CI
+
+# Configures this workflow to run every time a change is pushed to the
+# branch called `master`.
+# Also runs every Sunday at 3am (So we pick up any fixes from the past week in the base image)
+on:
+  push:
+    branches: ['main']
+  schedule:
+    - cron: '0 3 * * SUN'
+
+# Defines two custom environment variables for the workflow. These are used
+# for the Container registry domain, and a name for the Docker image that
+# this workflow builds.
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+# There is a single job in this workflow. It's configured to run on the
+# latest available version of Ubuntu.
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+
+    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions
+    # in this job.
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      # Uses the `docker/login-action` action to log in to the Container
+      # registry using the account and password that will publish the packages.
+      # Once published, the packages are scoped to the account defined here.
+      - name: Log in to GitHub Package Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      # This step uses [docker/metadata-action](https://github.com/docker/metadata-action#about)
+      # to extract tags and labels that will be applied to the specified image.
+      # The `id` "meta" allows the output of this step to be referenced in
+      # a subsequent step. The `images` value provides the base name for the
+      # tags and labels.
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=schedule
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}},enable=${{ !startsWith(github.ref, 'refs/tags/v0.') }}
+            type=sha
+            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
+
+      # This step uses the `docker/build-push-action` action to build the
+      # image, based on your repository's `Dockerfile`. If the build succeeds,
+      # it pushes the image to GitHub Packages.
+      # It uses the `context` parameter to define the build's context as the
+      # set of files located in the specified path. For more information, see
+      # "[Usage](https://github.com/docker/build-push-action#usage)" in the
+      # README of the `docker/build-push-action` repository.
+      # It uses the `tags` and `labels` parameters to tag and label the image
+      # with the output from the "meta" step.
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -1,6 +1,11 @@
 FROM alpine:edge
-LABEL maintainer=sylvain@huguet.me
-LABEL me.huguet.author="Sylvain Huguet"
+
+LABEL org.opencontainers.image.authors="Sylvain Huguet <sylvain@huguet.me>"
+LABEL org.opencontainers.image.source="https://github.com/shuguet/openconnect-udm"
+LABEL org.opencontainers.image.licenses="Unlicense"
+LABEL org.opencontainers.image.title="openconnect-udm"
+LABEL org.opencontainers.image.description="OpenConnect VPN Client for the UniFi Dream Machine Pro (Unofficial)"
+LABEL org.opencontainers.image.base.name="docker.io/library/alpine:edge"
 
 RUN apk add --no-cache --update oath-toolkit-oathtool openconnect