Add CI workflow

.github/workflows/build-deploy.yml

@@ -0,0 +1,44 @@
+name: Build and Deploy
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+  workflow_dispatch:
+  workflow_run:
+    workflows: ['Trigger Build']
+    types: [completed]
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+      - name: Log in to GHCR
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Fetch date
+        id: date
+        run: echo "DATE=$(date '+%Y%m%d')" >> "$GITHUB_OUTPUT"
+      - name: Build and push image
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64 # TODO: 32-bit (linux/arm/v7 and linux/386)
+          push: true # TODO: Only push on main
+          tags: ghcr.io/fwcd/docker-archlinux:latest,ghcr.io/fwcd/docker-archlinux:${{ steps.date.outputs.DATE }}

.github/workflows/trigger-build.yml

@@ -0,0 +1,25 @@
+name: Trigger Build
+
+on:
+  # Run every day at 07:20 (to avoid the peak times)
+  schedule:
+  - cron: '20 7 * * *'
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+jobs:
+  trigger-build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Configure Git user
+      run: |
+        git config --global user.name "github-actions[bot]"
+        git config --global user.email "github-actions[bot]@users.noreply.github.com"
+    - name: Create dummy commit
+      run: git commit --allow-empty -m "Trigger build ($(date -I))"
+    - name: Push
+      run: git push

README.md

@@ -1,3 +1,10 @@
 # Docker images of Arch Linux
 
-Unofficial Docker multi-platform images of Arch Linux, Arch Linux ARM and Arch Linux 32.
+[![Build and Deploy](https://github.com/fwcd/docker-archlinux/actions/workflows/build-deploy.yml/badge.svg)](https://github.com/fwcd/docker-archlinux/actions/workflows/build-deploy.yml)
+
+Unofficial, automated Docker multi-platform images of Arch Linux for the following architectures:
+
+| Architecture | Docker Platform | Distribution |
+| ------------ | --------------- | ------------ |
+| x86_64 | `linux/amd64` | [Arch Linux](https://archlinux.org) |
+| aarch64 | `linux/arm64` | [Arch Linux ARM](https://archlinuxarm.org) |