feat: remove lambda_layers stack and bundle layers directly in stacks

This is to avoid open bug: aws/aws-cdk#1972

Makefile

@@ -35,15 +35,13 @@ bootstrap: requirements run-tests cdk_version
 
 reminder:
 	@printf '$(GREEN)###########################################################################\n'
-	@printf '$(GREEN)# remember to add the DNS record to enable owned domain:\n#\n'
-	@printf '$(GREEN)# $(YELLOW)$(API_DOMAIN)	$(GREEN)CNAME	$(YELLOW)'
+	@printf '$(GREEN)remember to add $(YELLOW)$(API_DOMAIN)$(GREEN) CNAME DNS record to enable owned domain:\n'
+	@printf '$(YELLOW)'
 	@aws apigateway get-domain-name \
 		--profile $(AWS_PROFILE) \
 		--domain-name $(API_DOMAIN) \
-		|	grep regionalDomainName \
-		| cut -d ':' -f 2 \
-		| tr -d ',' \
-		| tr -d '"'
+		--query "regionalDomainName" \
+		--output text
 	@printf '$(GREEN)###########################################################################$(CLR)\n'
 
 synth: requirements run-tests clean cdk_version

lib/cdk.py

@@ -13,7 +13,6 @@
 
 from aws_cdk import core
 from stacks.api import ApiStack
-from stacks.lambda_layers import LambdaLayersStack
 from stacks.notifications import NotificationsStack
 from stacks.publish_to_social import SocialPublishStack
 
@@ -26,15 +25,6 @@
 ### Main CDK code follows
 APP = core.App()
 
-LAYERS_STACK = LambdaLayersStack(
-    APP,
-    'lambda-layers',
-    tags={
-        'Managed': 'cdk',
-        'Name': 'lambda-layers',
-    },
-)
-
 NOTIFICATIONS_STACK = NotificationsStack(
     APP,
     'notifications',
@@ -47,7 +37,6 @@
 PUBLISH_TO_SOCIAL_STACK = SocialPublishStack(
     APP,
     'publish-to-social',
-    lambda_layers=LAYERS_STACK.layers,
     tags={
         'Managed': 'cdk',
         'Name': 'publish-to-social',

lib/stacks/publish_to_social/__init__.py

@@ -1,6 +1,4 @@
 from os import environ
-from typing import Iterable
-
 
 from aws_cdk import (
     aws_lambda,
@@ -12,6 +10,7 @@
 )
 
 from utils.cdk import (
+    get_layer,
     get_lambda,
     code_from_path,
     DEFAULT_LOG_RETENTION,
@@ -20,8 +19,7 @@
 
 class SocialPublishStack(core.Stack):
 
-    def __init__(self, scope: core.Construct, id: str,  # pylint: disable=redefined-builtin
-                 lambda_layers: Iterable[aws_lambda.ILayerVersion], **kwargs) -> None:
+    def __init__(self, scope: core.Construct, id: str, **kwargs) -> None:  # pylint: disable=redefined-builtin
 
         super().__init__(scope, id, **kwargs)
 
@@ -32,6 +30,10 @@ def __init__(self, scope: core.Construct, id: str,  # pylint: disable=redefined-
 
         code = code_from_path(path='lib/stacks/{}/lambda'.format(id))
 
+        # Lambda Layers
+        lambda_layers = {layer: get_layer(self, layer_name=layer, prefix=id)
+                         for layer in ("bs4", "requests_oauthlib")}
+
         # PUBLISH lambda
         lambda_publish_to_social = get_lambda(
             self,
@@ -100,6 +102,5 @@ def build_lambda(name):
 
             topic.add_subscription(aws_sns_subscriptions.LambdaSubscription(_lambda))
 
-
         for social in social_lambdas:
             build_lambda(name=social)

lib/utils/cdk.py

@@ -64,25 +64,29 @@ def get_lambda(scope: core.Construct, id: str,  # pylint: disable=redefined-buil
     )
 
 
-def get_layer(scope: core.Construct, id: str,  # pylint: disable=redefined-builtin,invalid-name
-              code_path: str,
+def get_layer(scope: core.Construct,
+              layer_name: str,
+              prefix: str,
               compatible_runtimes: Optional[Iterable[aws_lambda.Runtime]] = None,
               description: Optional[str] = None) -> aws_lambda.LayerVersion:
 
     if not compatible_runtimes:
         compatible_runtimes = [DEFAULT_RUNTIME]
 
+    if not description:
+        description = f"Add {layer_name} dependency"
+
     return aws_lambda.LayerVersion(
         scope,
-        id,
-        code=code_from_path(path=code_path),
+        f"{prefix}-lambda-layer-python3-{layer_name}",
+        code=code_from_path(path=f"lib/layers/{layer_name}"),
         compatible_runtimes=compatible_runtimes,
         license="Apache-2.0",
         description=description,
     )
 
 
-def get_bucket(scope: core.Construct, construct_id: str,  # pylint: disable=redefined-builtin,invalid-name
+def get_bucket(scope: core.Construct, construct_id: str,
                expiration: Optional[core.Duration] = DEFAULT_S3_EXPIRATION) -> aws_s3.IBucket:
     return aws_s3.Bucket(
         scope,