feat: add AlwaysDeploy to AWS::Serverless::Api

[hoffa]

Issue #, if available

#660

And the ones deduplicated into the above:

1. Renaming a Serverless::Function used by an Api Gateway does not deploy the Gateway #634
2. Issue with API Gateway returning 500 server error after renaming function. #930
3. API Gateway Stages Deployment only gets updated when Swagger is updated #479
4. AWS::Serverless::Api deployment resource is not generated on Sub'ed Ref change #914
5. Updating API resource policy using mappings #1162
6. APIs are not getting deployed on Prod stage #1561
7. Changing minimumCompressionSize doesn't trigger API deployment. #1447
8. Bug: APIG Stage deployment isn't triggered on Lambda code update #2888

Description of changes

Add new property AlwaysDeploy (disabled by default) to AWS::Serverless::Api that always creates new deployment.

Using the time instead of something deterministic (e.g. hash of template and parameters) in case something outside of SAM's visibility changes (e.g. S3 object).

Description of how you validated changes

Based on template from #2888, save as template.yaml:

Transform: AWS::Serverless-2016-10-31
Resources:
  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      InlineCode: |
        exports.handler = async function (event) {
          return {
            statusCode: 200,
            body: JSON.stringify({ message: "Hello, foo!" }),
          }
        }
      Runtime: nodejs16.x
      AutoPublishAlias: live

  MyRole: 
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument: 
        Version: "2012-10-17"
        Statement: 
        - Effect: Allow
          Principal: {Service: "apigateway.amazonaws.com"}
          Action: sts:AssumeRole
      Policies: 
      - PolicyName: AllowInvokeLambdaFunctions
        PolicyDocument: 
          Version: "2012-10-17"
          Statement: 
          - Effect: Allow
            Action: lambda:InvokeFunction
            Resource: "*"

  MyApi:
    Type: AWS::Serverless::Api
    Properties:
       StageName: dev
       DefinitionBody:
        openapi: 3.0.0
        paths:
          /hello:
            get:
              x-amazon-apigateway-integration:
                credentials: !GetAtt MyRole.Arn
                uri: !Sub arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${MyFunction.Version}/invocations
                passthroughBehavior: when_no_match
                httpMethod: POST
                type: aws_proxy

Outputs:
  WebEndpoint:
    Description: "API Gateway endpoint URL"
    Value: !Sub "https://${MyApi}.execute-api.${AWS::Region}.amazonaws.com/dev/hello"

Deploy:

../serverless-application-model/bin/sam-translate.py --template-file template.yaml && sam deploy --region us-west-2 --resolve-s3 --capabilities CAPABILITY_IAM --stack-name test-always-deploy --template transformed-template.yaml

curl endpoint:

{"message":"Hello, foo!"}

Now change the Lambda:

sed -i.bak 's/Hello, foo!/Hello, bar!/g' template.yaml

Redeploy:

../serverless-application-model/bin/sam-translate.py --template-file template.yaml && sam deploy --region us-west-2 --resolve-s3 --capabilities CAPABILITY_IAM --stack-name test-always-deploy --template transformed-template.yaml

But the endpoint still shows the old output:

{"message":"Hello, foo!"}

Now, testing the fix, change template.yaml as such:

--- before.yaml	2023-02-28 10:19:46
+++ template.yaml	2023-02-28 10:20:03
@@ -35,6 +35,7 @@
   MyApi:
     Type: AWS::Serverless::Api
     Properties:
+       AlwaysDeploy: true
        StageName: dev
        DefinitionBody:
         openapi: 3.0.0

And redeploy:

../serverless-application-model/bin/sam-translate.py --template-file template.yaml && sam deploy --region us-west-2 --resolve-s3 --capabilities CAPABILITY_IAM --stack-name test-always-deploy --template transformed-template.yaml

And curl the endpoint again (sometimes takes a few seconds to change), and we get the proper output:

{"message":"Hello, bar!"}

Checklist

• Adheres to the development guidelines
• Add/update transform tests
  • Using correct values
  • Using wrong values
• Add/update integration tests

Examples?

Please reach out in the comments if you want to add an example. Examples will be
added to sam init through aws/aws-sam-cli-app-templates.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[xazhao]

How about AWS::Serverless::HttpApi?

[hoffa]

How about AWS::Serverless::HttpApi?

I haven't seen a similar issue reported for it. AWS::ApiGatewayV2::Stage has AutoDeploy FWIW.