Web Proxy Integrations

We recommend using Lambda Function URLs which are free, work with JavaScript & CSS assets out of the box, and are easy to map to a custom domain name. However, here are some SAM YAML snippets if you would like to use an alternate web server integration for your application. Remember, Lamby automatically detects which integration you are using.

note

The code snippets below are shown in diff format when compared to the latest files in the Quick Start cookiecutter project template.

API Gateway HTTP API

The HTTP API is the most modern integration after Function URLs. It is also really easy to add into our template file.

--- template.yaml
+++ template.yaml
@@ -28,14 +28,22 @@ Resources:
       DockerTag: web
     Properties:
       AutoPublishAlias: live
-      FunctionUrlConfig:
-        AuthType: NONE
       DeploymentPreference:
         Type: AllAtOnce
+      Events:
+        HttpApiProxy:
+          Type: HttpApi
+          Properties:
+            ApiId: !Ref RailsHttpApi
       MemorySize: 1792
       PackageType: Image
       Timeout: 30
 
+  RailsHttpApi:
+     Type: AWS::Serverless::HttpApi
+     Properties:
+       StageName: !Ref RailsEnv

API Gateway REST API

The REST API is a little more verbose, but it essentially sets up a simple proxy that Lamby can use. The integration uri lines use the :live alias since our starter defaults to using an AutoPublishAlias: live

Application Load Balancer

Using Lambda's ALB Integration is a great way to setup your application on a private VPC. However, they limit response payloads to less than 1MB vs. the 6MB limit for API Gateway. Using Rack::Deflater can help with this if needed. These resources make use of the VPC subnets and security groups mentioned in the Database & VPCs guide.

--- template.yaml
+++ template.yaml
@@ -28,14 +28,52 @@ Resources:
       DockerTag: web
     Properties:
       AutoPublishAlias: live
-      FunctionUrlConfig:
-        AuthType: NONE
       DeploymentPreference:
         Type: AllAtOnce
       MemorySize: 1792
       PackageType: Image
       Timeout: 30
 
+  RailsLoadBalancer:
+    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
+    Properties:
+      Scheme: internal
+      SubnetIds:
+        - subnet-09792e6cd06dd59ad
+        - subnet-0501f3136415021da
+      SecurityGroupIds:
+        - sg-07be99aff5fb14557
+
+  RailsLoadBalancerHttpsListener:
+    Type: AWS::ElasticLoadBalancingV2::Listener
+    Properties:
+      Certificates:
+        - CertificateArn: arn:aws:acm:us-east-1:123456789012:certificate/38613b58-c21e-11eb-8529-0242ac130003
+      DefaultActions:
+        - TargetGroupArn: !Ref RailsLoadBalancerTargetGroup
+          Type: forward
+      LoadBalancerArn: !Ref RailsLoadBalancer
+      Port: 443
+      Protocol: HTTPS
+
+  RailsLoadBalancerTargetGroup:
+    Type: AWS::ElasticLoadBalancingV2::TargetGroup
+    DependsOn: RailsLambdaInvokePermission
+    Properties:
+      TargetType: lambda
+      TargetGroupAttributes:
+        - Key: lambda.multi_value_headers.enabled
+          Value: true
+      Targets:
+        - Id: !GetAtt RailsLambda.Arn
+
+  RailsLambdaInvokePermission:
+    Type: AWS::Lambda::Permission
+    Properties:
+      FunctionName: !GetAtt RailsLambda.Arn
+      Action: "lambda:InvokeFunction"
+      Principal: elasticloadbalancing.amazonaws.com