feat: Automate Docker image builds with multi-architecture support (#17)

.github/workflows/ci.yml

@@ -0,0 +1,62 @@
+name: Continuous Integration
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '0 12 * * *'
+  push:
+    branches:
+      - 'main'
+      - 'renovate/**'
+    tags:
+      - 'v*.*.*'
+  pull_request:
+    branches:
+      - 'main'
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Build Docker image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout GitHub Repository
+        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4.1.4
+
+      - name: Docker metadata
+        id: metadata
+        uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81 # v5.5.1
+        with:
+          images: |
+            newrelic/k8s-agents-operator
+          tags: |
+            # reflects the last commit of the active branch
+            type=edge
+            # nightly tag
+            type=schedule
+            # push tag event
+            type=semver,pattern={{version}}
+            # push tag event
+            type=semver,pattern={{major}}.{{minor}}
+
+      - name: Login to Docker Hub
+        if: github.event_name != 'pull_request' && !startsWith(github.ref, 'refs/heads/renovate')
+        uses: docker/login-action@e92390c5fb421da1463c202d546fed0ec5c39f20 # v3.1.0
+        with:
+          username: ${{ secrets.K8S_AGENTS_DOCKERHUB_USERNAME }}
+          password: ${{ secrets.K8S_AGENTS_DOCKERHUB_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@d70bba72b1f3fd22344832f00baa16ece964efeb # v3.3.0
+
+      - name: Build and push
+        uses: docker/build-push-action@2cdde995de11925a030ce8070c3d77a52ffcf1c0 # v5.3.0
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64,linux/arm
+          file: ./Dockerfile
+          push: ${{ github.event_name != 'pull_request' && !startsWith(github.ref, 'refs/heads/renovate') }}
+          tags: ${{ steps.metadata.outputs.tags }}
+          labels: ${{ steps.metadata.outputs.labels }}