Build + Push cov-diff during CI runs

CI currently spends 30s building this every run. We can save that time by pre-building this action image.

Author: ryder-gillen-ltk

.github/workflows/integration.yaml

@@ -2,12 +2,25 @@ name: Integration Test
 
 on:
   pull_request:
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*.*.*'
+  workflow_dispatch:
+
+env:
+  AWS_DEFAULT_REGION: us-east-1
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
+
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
@@ -28,8 +41,58 @@ jobs:
           diff: pr.diff
           module: github.com/panagiotisptr/cov-diff
 
-      - name: Comment
+      - name: Comment on PR
         uses: mshick/add-pr-comment@v2
         with:
           message: |
             Coverage on new code: ${{ steps.selftest.outputs.covdiff }}%
+
+  build_push:
+    needs: test
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Configure AWS credentials
+        if: github.event_name != 'pull_request'
+        uses: aws-actions/configure-aws-credentials@v4
+        with:
+          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+          aws-region: ${{ env.AWS_DEFAULT_REGION }}
+
+      - name: Login to Amazon ECR
+        if: github.event_name != 'pull_request'
+        id: login-ecr
+        uses: aws-actions/amazon-ecr-login@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Determine ECR image tags
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ${{ steps.login-ecr.outputs.registry && format('{0}/', steps.login-ecr.outputs.registry) || '' }}cov-diff
+          tags: |
+            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
+            type=sha
+            type=semver,pattern=v{{version}},event=tag
+
+      - name: Build and Push Docker image to ECR
+        id: build_and_push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          cache-from: type=gha,scope=${{ github.workflow }}
+          cache-to: type=gha,mode=max,scope=${{ github.workflow }}