Automated multi-platform build and DockerHub publication (#8)

* Automated multi-arch build

This setup uses GitHub Actions to build an image for arm/v7 and arm64 then publish them on DockerHub (you need to setup repo secrets first) every time you want (workflow_dispatch), every push, every pull requests (pull_requests), or on a schedule (cronjob) :)

Remove the triggers you don't want.

Reminder: if you ever move the Dockerfile (or some dependencies), you will have to correct the Dockerfile path (and/or the context path).

* Create dependabot.yml

This checks the dependencies' versions for the Actions everyday and creates a pull request if there are new versions available.

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"

.github/workflows/Build+push Immich.yml

@@ -0,0 +1,46 @@
+name: Build+push Immich
+
+on:
+  # Triggers the workflow on push or pull request events but only for the main branch
+  #schedule:
+    # * is a special character in YAML so you have to quote this string
+    #- cron:  '0 0 * * *'
+  workflow_dispatch:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  buildandpush:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2.4.0
+        with:
+          ref: 'main' # branch
+      # https://github.com/docker/setup-qemu-action#usage
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1.2.0
+      # https://github.com/marketplace/actions/docker-setup-buildx
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v1.6.0
+      # https://github.com/docker/login-action#docker-hub
+      - name: Login to Docker Hub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      # https://github.com/docker/build-push-action#multi-platform-image
+      - name: Build and push Immich
+        uses: docker/build-push-action@v2.9.0
+        with:
+          context: ./server
+          file: ./server/Dockerfile
+          #platforms: linux/amd64,linux/arm64,linux/riscv64,linux/ppc64le,linux/s390x,linux/386,linux/mips64le,linux/mips64,linux/arm/v7,linux/arm/v6
+          platforms: linux/arm/v7,linux/arm64
+          pull: true
+          push: true
+          tags: |
+            alextran1502/immich:latest