ci: start using ECR for container caches (#77)

.github/workflows/pre-merge-python.yml

@@ -35,40 +35,45 @@ jobs:
     name: Build and Test - ${{ matrix.framework }}
     env:
       CONTAINER_ID: test_${{ github.run_id }}_${{ github.run_attempt }}_${{ github.job }}_${{ matrix.framework }}
-      IMAGE_TAG: ghcr.io/${{ github.repository }}:latest-${{ matrix.framework }}
       PYTEST_XML_FILE: pytest_test_report.xml
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
-      - name: Login to GitHub Container Registry
-        uses: docker/login-action@v3
+      - name: Configure AWS credentials
+        uses: aws-actions/configure-aws-credentials@v4
         with:
-          registry: ghcr.io
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
+          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+          aws-region: ${{ secrets.AWS_DEFAULT_REGION }}
+      - name: Login to Amazon ECR
+        id: login-ecr
+        uses: aws-actions/amazon-ecr-login@v2
+      - name: Define Image Tag
+        id: define_image_tag
+        run: |
+          echo "image_tag=${{ steps.login-ecr.outputs.registry }}/${{ github.repository }}:latest-${{ matrix.framework }}" >> $GITHUB_OUTPUT
       - name: Decide on cache
         id: which_caches
         run: |
           set +e
           if [ "${{ github.event_name }}" == "pull_request" ]; then
-
             echo "Not pushing to container image cache"
             echo "cache_to_location=" >> $GITHUB_OUTPUT
           else
-            echo "Pushing ${{ env.IMAGE_TAG }} to container image cache"
-            echo "cache_to_location=--cache-to \"type=registry,ref=${{ env.IMAGE_TAG }},image-manifest=true,mode=max\"" >> $GITHUB_OUTPUT
+            echo "Pushing ${{ steps.define_image_tag.outputs.image_tag }} to container image cache"
+            echo "cache_to_location=--cache-to \"type=registry,ref=${{ steps.define_image_tag.outputs.image_tag }},image-manifest=true,mode=max\"" >> $GITHUB_OUTPUT
           fi
-          echo "cache_from_location=--cache-from \"type=registry,ref=${{ env.IMAGE_TAG }}\"" >> $GITHUB_OUTPUT
+          echo "cache_from_location=--cache-from \"type=registry,ref=${{ steps.define_image_tag.outputs.image_tag }}\"" >> $GITHUB_OUTPUT
       - name: Build image
         run: |
-          ./container/build.sh --tag ${{ env.IMAGE_TAG }} --framework ${{ matrix.framework }} ${{ steps.which_caches.outputs.cache_from_location }} ${{ steps.which_caches.outputs.cache_to_location }}
+          ./container/build.sh --tag ${{ steps.define_image_tag.outputs.image_tag }} --framework ${{ matrix.framework }} ${{ steps.which_caches.outputs.cache_from_location }} ${{ steps.which_caches.outputs.cache_to_location }}
       - name: Run pytest
         env:
           PYTEST_MARKS: "pre_merge or mypy"
         run: |
-          docker run -w /workspace --name ${{ env.CONTAINER_ID }} ${{ env.IMAGE_TAG }} pytest --basetemp=/tmp --junitxml=${{ env.PYTEST_XML_FILE }} -m "${{ env.PYTEST_MARKS }}"
+          docker run -w /workspace --name ${{ env.CONTAINER_ID }} ${{ steps.define_image_tag.outputs.image_tag }} pytest --basetemp=/tmp --junitxml=${{ env.PYTEST_XML_FILE }} -m "${{ env.PYTEST_MARKS }}"
       - name: Copy test report from test Container
         if: always()
         run: |