chore(docs): output the Layer ARN to a artifact

.github/workflows/reusable_deploy_layer_stack.yml

@@ -94,6 +94,14 @@ jobs:
       - name: unzip artefact
         run: unzip cdk.out.zip
       - name: CDK Deploy Layer
-        run: cdk deploy --app cdk.out --context region=${{ matrix.region }} 'LayerStack' --require-approval never --verbose
+        run: cdk deploy --app cdk.out --context region=${{ matrix.region }} 'LayerStack' --require-approval never --verbose --outputs-file cdk-outputs.json
+      - name: Store latest layer ARN
+        if: ${{ inputs.stage == 'PROD' }}
+        run: jq -c '.LayerStack.LatestLayerArn' cdk-outputs.json > cdk-layer-stack-${{ matrix.region }}-layer-version.txt
       - name: CDK Deploy Canary
         run: cdk deploy --app cdk.out --context region=${{ matrix.region}} --parameters DeployStage="${{ inputs.stage }}" 'CanaryStack' --require-approval never --verbose
+      - name: Save layer stack ARN artifact
+        uses: actions/upload-artifacts@v3
+        with:
+          name: cdk-layer-stack
+          path: cdk-layer-stack*

docs/plugins/lambda_layer_version.py

@@ -0,0 +1,30 @@
+import os
+import re
+from pathlib import Path
+
+from mkdocs.config import Config
+from mkdocs.structure.files import Files
+from mkdocs.structure.pages import Page
+
+
+def inject(markdown: str, page: Page, config: Config, files: Files):
+    if not page.is_homepage:
+        return markdown
+
+    # Try to see if we have a cdk-layer-stack directory.
+    # This is created during the layer build, saved as an artifact, and downloaded before the jobs runs
+    if not os.path.exists("cdk-layer-stack"):
+        print("No cdk-layer-stack directory found, not replacing lambda layer versions")
+        return markdown
+
+    # For each cdk output file, replace all the lambda layer occurrences in the docs
+    files = Path("cdk-layer-stack").glob("*")
+    for cdk_file in files:
+        with open(cdk_file, "r") as f:
+            layer_version_arn = f.readlines()[0].strip()
+            layer_version_prefix = ":".join(layer_version_arn.split(":")[:-1])
+
+            # replace the prefix with the new version
+            markdown = re.sub(rf"{layer_version_prefix}:\d+", layer_version_arn, markdown)
+
+    return markdown

mkdocs.yml

@@ -89,6 +89,9 @@ copyright: Copyright © 2022 Amazon Web Services
 plugins:
   - git-revision-date
   - search
+  - mkdocs-simple-hooks:
+      hooks:
+        on_page_markdown: "docs.plugins.lambda_layer_version:inject"
 
 extra_css:
   - stylesheets/extra.css