Added Github Actions build workflow

.github/workflows/build-image.yaml

@@ -0,0 +1,67 @@
+name: build-image
+
+on:
+  push:
+    paths-ignore:
+    - 'README.md'
+    branches:
+    - main
+    - dev
+    tags:
+    - '[0-9]+.*'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Convert repository name ot image name
+        id: image_name
+        run: |
+          sed -E -e 's/docker-//' -e 's/^/image_name=/' <<<"${{ github.repository }}" >> "$GITHUB_OUTPUT"
+
+      - name: Generate Docker tag names
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          # list of Docker images to use as base name for tags
+          images: |
+            ghcr.io/${{ steps.image_name.outputs.image_name }}
+            ${{ steps.image_name.outputs.image_name }}
+          # generate Docker tags based on the following events/attributes
+          tags: |
+            # set latest tag for default branch
+            type=raw,value=latest,enable={{is_default_branch}}
+            # set edge tag for dev branch
+            type=edge,enable=true,branch=dev
+            # Tags for non SemVer tag names
+            type=match,pattern=([0-9]+.*),group=1
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          platforms: linux/arm/v7,linux/arm64/v8,linux/amd64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}

README.md

@@ -8,10 +8,10 @@
 
 [SOGo](https://www.sogo.nu) is a fully supported and trusted groupware server
 with a focus on scalability and open standards. SOGo is released under the GNU
-GPL/LGPL v2 and above.
+GPL/LGPL v2 and above.  
+The app features a web interface for an IMAP server, (shared) addressbook and calendar management with full CardDAV and CaldDAV support.
 
-This Dockerfile packages SOGo compiled from a defined production source tag, together with Apache 2 and
-memcached. 
+This Dockerfile packages SOGo compiled from a defined production source tag, together with Apache 2 and memcached. 
 This means that this image does not rely on the SOGo packages getting updated by any package managers while at the same time using a pinned production tag instead of a nightly release.  
 The image is set up in a way to support High Availability (multiple replicas) in a Kubernetes Cluster and provides example files for Docker as well as Kubernetes setups.