DEV: Build base images for ARM64 platform in a seperate daily job

Why this change?

We're currently building a base image for arm64 platforms as part of the
CI workflow. However, building it on Github action via emulation is too
slow and makes it meaningless to include as part of the CI workflow.

What does this change do?

This change moves the building of the bage image targeting the arm64
platform completely to a scheduled job that runs outside of the normal
CI workflow. This will also enable us to build the images for the test
and dev environment eventually as part of the workflow which we intend
to do in a follow up commit.

.github/workflows/arm64-build.yml

@@ -0,0 +1,66 @@
+on:
+  pull_request:
+  schedule:
+    - cron: "0 0 * * *"
+
+concurrency:
+  group: build-arm64-${{ format('{0}-{1}', github.head_ref || github.run_number, github.job) }}
+  cancel-in-progress: true
+
+env:
+  BUILDKIT_PROGRESS: plain
+
+jobs:
+  base:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 1
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+        with:
+          platforms: arm64
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v2
+      - name: build slim image
+        run: |
+          cd image && ruby auto_build.rb base_slim_arm64
+      - name: tag slim images
+        id: tag-images
+        run: |
+          TAG=`date +%Y%m%d-%H%M`
+          echo "tag=$(echo $TAG)" >> $GITHUB_OUTPUT
+          docker tag discourse/base:build_slim_arm64 discourse/base:2.0.$TAG-slim-arm64
+          docker tag discourse/base:build_slim_arm64 discourse/base:slim-arm64
+      - name: build release image
+        run: |
+          cd image && ruby auto_build.rb base_arm64
+      - name: tag release images
+        run: |
+          TAG=${{ steps.tag-images.outputs.tag }}
+          docker tag discourse/base:build_arm64 discourse/base:2.0.$TAG-arm64
+          docker tag discourse/base:build_arm64 discourse/base:release-arm64
+      - name: build test_build image
+        run: |
+          cd image && ruby auto_build.rb discourse_test_build_arm64
+      - name: run specs
+        run: |
+          docker run --rm -e RUBY_ONLY=1 -e USE_TURBO=1 -e SKIP_PLUGINS=1 -e SKIP_LINT=1 discourse/discourse_test:build_arm64
+      - name: Print summary
+        run: |
+          docker images discourse/base
+      - name: push to dockerhub
+        if: success() && (github.ref == 'refs/heads/main')
+        env:
+          DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD }}
+        run: |
+          TAG=${{ steps.tag-images.outputs.tag }}
+          docker login --username discoursebuild --password $DOCKERHUB_PASSWORD
+          docker push discourse/base:2.0.$TAG-slim-arm64
+          docker push discourse/base:slim-arm64
+          docker tag discourse/base:slim-arm64 discourse/base:aarch64
+          docker push discourse/base:2.0.$TAG-arm64
+          docker push discourse/base:release-arm64
+          docker push discourse/base:aarch64

.github/workflows/build.yml

@@ -4,7 +4,7 @@ on:
       - main
   pull_request:
   schedule:
-    - cron: '0 0 * * *'
+    - cron: "0 0 * * *"
 
 concurrency:
   group: build-${{ format('{0}-{1}', github.head_ref || github.run_number, github.job) }}
@@ -119,37 +119,3 @@ jobs:
           docker tag discourse/discourse_dev:build discourse/discourse_dev:release
           docker login --username discoursebuild --password $DOCKERHUB_PASSWORD
           docker push discourse/discourse_dev:release
-  aarch64:
-    runs-on: ubuntu-latest
-    needs: base
-    services:
-      registry:
-        image: registry
-        ports:
-          - 5000:5000
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 1
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v2
-      - name: Set up Docker Buildx
-        id: buildx
-        uses: docker/setup-buildx-action@v2
-      - name: build slim image
-        run: |
-          cd image && ruby auto_build.rb base_slim_arm64
-          docker tag discourse/base:aarch64-slim localhost:5000/discourse/base:build_slim_arm64
-      - name: tag slim image as release
-        working-directory: image/base
-        run: |
-          docker tag discourse/base:aarch64-slim discourse/base:aarch64
-      - name: Print summary
-        run: docker images discourse/base
-      - name: push to dockerhub
-        if: success() && (github.ref == 'refs/heads/main')
-        env:
-          DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD }}
-        run: |
-          docker login --username discoursebuild --password $DOCKERHUB_PASSWORD
-          docker push discourse/base:aarch64

image/auto_build.rb

@@ -19,14 +19,29 @@
     tag: "discourse/base:build",
     extra_args: "-f release.Dockerfile",
   },
+  base_arm64: {
+    name: "base",
+    tag: "discourse/base:build_arm64",
+    extra_args: "-f release.Dockerfile --platform linux/arm64",
+  },
   discourse_test_build: {
     name: "discourse_test",
     tag: "discourse/discourse_test:build",
   },
+  discourse_test_build_arm64: {
+    name: "discourse_test",
+    tag: "discourse/discourse_test:build_arm64",
+    extra_args: "--platform linux/arm64",
+  },
   discourse_dev: {
     name: "discourse_dev",
     tag: "discourse/discourse_dev:build",
   },
+  discourse_dev_arm64: {
+    name: "discourse_dev",
+    tag: "discourse/discourse_dev:build_arm64",
+    extra_args: "--platform linux/arm64",
+  },
 }
 
 def run(command)