Simplify and restructure GitHub Actions workflow for ARM64 Docker image build, improving readability and consolidating steps.

Author: Spomky

.github/workflows/build.yml

@@ -2,40 +2,40 @@ name: Build and Push gh-runner (ARM64)
 
 on:
   push:
-    branches: [ main ]
-    tags: [ '*' ]
+    branches:
+      - main
+    tags:
+      - '*'
   workflow_dispatch:
 
 env:
+  IMAGE_NAME: ghcr.io/spomky-labs/gh-runner
   RUNNER_VERSION: 2.327.1
 
 jobs:
-  build-arm64:
-    runs-on: ubuntu-24.04-arm
+  build:
+    name: 🐳 Build Docker (ARM64)
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
     steps:
-      - name: Checkout
-        uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
-      - name: Lowercase owner
-        id: vars
-        run: echo "owner_lc=${GITHUB_REPOSITORY_OWNER,,}" >> "$GITHUB_OUTPUT"
-
-      - name: Log in to GHCR
+      - name: Docker login to GHCR
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Build image (ARM64)
+      - name: Build and push image
         run: |
-          IMAGE_NAME=ghcr.io/${{ steps.vars.outputs.owner_lc }}/gh-runner
+          IMAGE_TAG="${IMAGE_NAME}:latest"
+          echo "Building ${IMAGE_TAG}"
           docker build \
             --build-arg RUNNER_VERSION=${RUNNER_VERSION} \
             --platform linux/arm64 \
-            -t $IMAGE_NAME:latest .
-
-      - name: Push image
-        run: |
-          IMAGE_NAME=ghcr.io/${{ steps.vars.outputs.owner_lc }}/gh-runner
-          docker push $IMAGE_NAME:latest
+            -t ${IMAGE_TAG} \
+            .
+          docker push ${IMAGE_TAG}