Add Docker build workflow for GitHub Actions

Author: r-near

.github/workflows/docker.yml

@@ -0,0 +1,55 @@
+name: Docker Build
+
+on:
+  push:
+    branches: [ main ]
+    tags: [ 'v*' ]
+  pull_request:
+    branches: [ main ]
+
+env:
+  REGISTRY: europe-west4-docker.pkg.dev
+  PROJECT_ID: bridge-misc
+  REPOSITORY: omni-bridge-docker-images
+
+
+jobs:
+  build:
+    runs-on: warp-ubuntu-latest-x64-2x
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      
+    - name: Authenticate to Google Cloud
+      uses: google-github-actions/auth@v2
+      with:
+        credentials_json: ${{ secrets.GCP_SA_KEY }}
+
+    - name: Configure Docker to use gcloud as credential helper
+      run: gcloud auth configure-docker ${{ env.REGISTRY }}
+
+    - name: Extract metadata
+      id: meta
+      uses: docker/metadata-action@v5
+      with:
+        images: ${{ env.REGISTRY }}/${{ env.PROJECT_ID }}/${{ env.REPOSITORY }}/bitcoin-augur-reference
+        tags: |
+          type=ref,event=branch
+          type=ref,event=pr
+          type=semver,pattern={{version}}
+          type=semver,pattern={{major}}.{{minor}}
+          type=sha
+
+    - name: Build and push
+      uses: Warpbuilds/build-push-action@v6
+      with:
+        context: .
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}
+        cache-from: type=gha
+        cache-to: type=gha,mode=max