Refactor Lambda deployment workflow to optimize image build process. Introduced a build metadata preparation step to check for existing images before building and pushing, enhancing efficiency. Updated ECR login and Docker build steps to conditionally execute based on the presence of existing images, improving deployment reliability.

Author: Thomas-Boyle

.github/workflows/deploy-lambda-artifact.yml

@@ -190,16 +190,9 @@ jobs:
 
           echo "deployment_mode=${deployment_mode}" >> "$GITHUB_OUTPUT"
 
-      - name: Login to Amazon ECR
-        id: login-ecr
-        if: ${{ steps.decide.outputs.deployment_mode == 'build' }}
-        uses: aws-actions/amazon-ecr-login@183a1442edf41672e66566b7fc560e297a290896
-
-      - name: Build, publish and emit digest manifest
-        id: build
+      - name: Prepare build metadata
+        id: build-check
         if: ${{ steps.decide.outputs.deployment_mode == 'build' }}
-        env:
-          ECR_REGISTRY: ${{ steps.login-ecr.outputs.registry }}
         run: |
           set -euo pipefail
 
@@ -208,10 +201,18 @@ jobs:
           GIT_TAG="${TAG_PREFIX}git-${SHORT_SHA}"
           REL_TAG="${TAG_PREFIX}rel-${RELEASE_STAMP}"
 
-          IMAGE_URI_GIT="${ECR_REGISTRY}/${ECR_REPOSITORY}:${GIT_TAG}"
-          IMAGE_URI_REL="${ECR_REGISTRY}/${ECR_REPOSITORY}:${REL_TAG}"
+          REPOSITORY_URI="$(
+            aws ecr describe-repositories \
+              --repository-names "${ECR_REPOSITORY}" \
+              --region "${AWS_REGION}" \
+              --query 'repositories[0].repositoryUri' \
+              --output text
+          )"
 
-          IMAGE_DIGEST="$(
+          IMAGE_URI_GIT="${REPOSITORY_URI}:${GIT_TAG}"
+          IMAGE_URI_REL="${REPOSITORY_URI}:${REL_TAG}"
+
+          EXISTING_IMAGE_DIGEST="$(
             aws ecr describe-images \
               --repository-name "${ECR_REPOSITORY}" \
               --region "${AWS_REGION}" \
@@ -220,19 +221,58 @@ jobs:
               --output text 2>/dev/null || true
           )"
 
-          if [ -z "${IMAGE_DIGEST}" ] || [ "${IMAGE_DIGEST}" = "None" ]; then
-            docker build -f "${DOCKERFILE_PATH}" -t "${IMAGE_URI_GIT}" -t "${IMAGE_URI_REL}" "${DOCKER_CONTEXT_PATH}"
-            docker push "${IMAGE_URI_GIT}"
-            docker push "${IMAGE_URI_REL}"
+          SHOULD_BUILD="false"
+          if [ -z "${EXISTING_IMAGE_DIGEST}" ] || [ "${EXISTING_IMAGE_DIGEST}" = "None" ]; then
+            SHOULD_BUILD="true"
+          fi
 
-            IMAGE_DIGEST="$(
-              aws ecr describe-images \
-                --repository-name "${ECR_REPOSITORY}" \
-                --region "${AWS_REGION}" \
-                --image-ids imageTag="${GIT_TAG}" \
-                --query 'imageDetails[0].imageDigest' \
-                --output text
-            )"
+          echo "git_tag=${GIT_TAG}" >> "$GITHUB_OUTPUT"
+          echo "release_tag=${REL_TAG}" >> "$GITHUB_OUTPUT"
+          echo "repository_uri=${REPOSITORY_URI}" >> "$GITHUB_OUTPUT"
+          echo "image_uri_git=${IMAGE_URI_GIT}" >> "$GITHUB_OUTPUT"
+          echo "image_uri_rel=${IMAGE_URI_REL}" >> "$GITHUB_OUTPUT"
+          echo "existing_image_digest=${EXISTING_IMAGE_DIGEST}" >> "$GITHUB_OUTPUT"
+          echo "should_build=${SHOULD_BUILD}" >> "$GITHUB_OUTPUT"
+
+      - name: Login to Amazon ECR
+        id: login-ecr
+        if: ${{ steps.decide.outputs.deployment_mode == 'build' && steps.build-check.outputs.should_build == 'true' }}
+        uses: aws-actions/amazon-ecr-login@062b18b96a7aff071d4dc91bc00c4c1a7945b076
+
+      - name: Set up Docker Buildx
+        if: ${{ steps.decide.outputs.deployment_mode == 'build' && steps.build-check.outputs.should_build == 'true' }}
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and publish image with layer caching
+        id: build-image
+        if: ${{ steps.decide.outputs.deployment_mode == 'build' && steps.build-check.outputs.should_build == 'true' }}
+        uses: docker/build-push-action@v6
+        with:
+          context: ${{ env.DOCKER_CONTEXT_PATH }}
+          file: ${{ env.DOCKERFILE_PATH }}
+          push: true
+          tags: |
+            ${{ steps.build-check.outputs.image_uri_git }}
+            ${{ steps.build-check.outputs.image_uri_rel }}
+          cache-from: type=gha,scope=${{ env.ECR_REPOSITORY }}
+          cache-to: type=gha,mode=max,scope=${{ env.ECR_REPOSITORY }}
+
+      - name: Emit build digest manifest
+        id: build
+        if: ${{ steps.decide.outputs.deployment_mode == 'build' }}
+        env:
+          REPOSITORY_URI: ${{ steps.build-check.outputs.repository_uri }}
+          GIT_TAG: ${{ steps.build-check.outputs.git_tag }}
+          REL_TAG: ${{ steps.build-check.outputs.release_tag }}
+          EXISTING_IMAGE_DIGEST: ${{ steps.build-check.outputs.existing_image_digest }}
+          SHOULD_BUILD: ${{ steps.build-check.outputs.should_build }}
+          BUILT_IMAGE_DIGEST: ${{ steps.build-image.outputs.digest }}
+        run: |
+          set -euo pipefail
+
+          IMAGE_DIGEST="${EXISTING_IMAGE_DIGEST}"
+          if [ "${SHOULD_BUILD}" = "true" ]; then
+            IMAGE_DIGEST="${BUILT_IMAGE_DIGEST}"
           else
             echo "Immutable tag '${GIT_TAG}' already exists. Reusing existing image digest."
           fi
@@ -242,7 +282,7 @@ jobs:
             exit 1
           fi
 
-          IMAGE_URI_PINNED="${ECR_REGISTRY}/${ECR_REPOSITORY}@${IMAGE_DIGEST}"
+          IMAGE_URI_PINNED="${REPOSITORY_URI}@${IMAGE_DIGEST}"
           echo "image_version=${GIT_TAG}" >> "$GITHUB_OUTPUT"
           echo "image_digest=${IMAGE_DIGEST}" >> "$GITHUB_OUTPUT"
           echo "image_uri=${IMAGE_URI_PINNED}" >> "$GITHUB_OUTPUT"