Pass lambda function name to uri in swagger file - amazon-web-services

Question

I am creating an api gateway with cloudformation. Actually I am using a swagger.yaml which is uploaded in s3 as body. I want to keep the swagger.yaml parameterized, but I can't pass the arn of my lambda function to the file. I have tried some solutions but nothing seems to work for me. I hope anyone can help me here.
Api GW:
AWSTemplateFormatVersion: 2010-09-09
Description: API
Parameters:
application:
Type: String
Default: test
apiGatewayName:
Type: String
Default: hub
apiGatewayStageName:
Type: String
AllowedPattern: "[a-z0-9]+"
Default: dev
apiGatewayHTTPMethod:
Type: String
Default: GET
lambdaFunctionName:
Type: String
AllowedPattern: "[a-zA-Z0-9]+[a-zA-Z0-9-]+[a-zA-Z0-9]+"
Default: crawler
############################ REST API ############################
Resources:
apiGateway:
Type: AWS::ApiGateway::RestApi
Properties:
EndpointConfiguration:
Types:
- REGIONAL
BodyS3Location:
Bucket: !Sub ${application}-${apiGatewayStageName}-${AWS::AccountId}
Key: api_swagger.yml
Name: !Ref apiGatewayName
Tags:
-
Key: Project
Value: test
apiGatewayDeployment:
Type: AWS::ApiGateway::Deployment
Properties:
RestApiId: !Ref apiGateway
StageName: !Ref apiGatewayStageName
Tags:
-
Key: Project
Value: test
############################ usagePlan ############################
usagePlan:
Type: 'AWS::ApiGateway::UsagePlan'
DependsOn:
apiKey
Properties:
ApiStages:
- ApiId: !Ref apiGateway
Stage: !Ref apiGatewayStageName
Description: test usage plan
Quota:
Limit: 1000
Period: MONTH
Throttle:
BurstLimit: 200
RateLimit: 100
UsagePlanName: ${application}-usageplan
Tags:
-
Key: Project
Value: test
usagePlanKey:
Type: 'AWS::ApiGateway::UsagePlanKey'
DependsOn:
usagePlan
Properties:
KeyId: !Ref apiKey
KeyType: API_KEY
UsagePlanId: !Ref usagePlan
Tags:
-
Key: Project
Value: test
############################ apiKey ############################
apiKey:
Type: AWS::ApiGateway::ApiKey
DependsOn:
- apiGatewayDeployment
- apiGateway
Properties:
CustomerId: String
Description: ApiKey for ${application}-api
Enabled: True
Name: ${application}-apikey
StageKeys:
- RestApiId: !Ref apiGateway
StageName: !Ref apiGatewayStageName
Tags:
-
Key: Project
Value: test
############################ apiGatewayRootMethod ############################
lambdaRootMethodInvoke:
Type: AWS::Lambda::Permission
Properties:
Action: lambda:InvokeFunction
FunctionName: !GetAtt lambdaFunction.Arn
Principal: apigateway.amazonaws.com
SourceArn: !Sub arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${apiGateway}/*/POST/
Tags:
-
Key: Project
Value: test
############################ applicationRuleBufferZoneMethod ############################
lambdaBufferZoneInvoke:
Type: AWS::Lambda::Permission
Properties:
Action: lambda:InvokeFunction
FunctionName: !GetAtt lambdaFunction.Arn
Principal: apigateway.amazonaws.com
SourceArn: !Sub arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${apiGateway}/*/${apiGatewayHTTPMethod}/application/rule/bufferZoneList
Tags:
-
Key: Project
Value: test
############################ Lambda Functions ############################
lambdaFunction:
Type: AWS::Lambda::Function
DependsOn:
- apiGateway
Properties:
Layers:
- arn:aws:lambda:eu-central-1:770693421928:layer:Klayers-python38-boto3:108
Code:
S3Bucket: !Sub ${application}-${apiGatewayStageName}-${AWS::AccountId}
S3Key: crawler.zip
Description: DynamoDB Crawler
FunctionName: !Ref lambdaFunctionName
Handler: crawler.lambda_handler
MemorySize: 128
Role: !GetAtt lambdaIAMRole.Arn
Runtime: python3.8
Tags:
-
Key: Project
Value: test
############################ Lambda IAM Role ############################
lambdaIAMRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: 2012-10-17
Statement:
- Action:
- sts:AssumeRole
Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Policies:
- PolicyDocument:
Version: 2012-10-17
Statement:
- Action:
- dynamodb:DeleteItem
- dynamodb:GetItem
- dynamodb:PutItem
- dynamodb:Query
- dynamodb:Scan
- dynamodb:UpdateItem
Effect: Allow
Resource: "*"
PolicyName: dynamoDBAccess
- PolicyDocument:
Version: 2012-10-17
Statement:
- Action:
- logs:CreateLogGroup
- logs:CreateLogStream
- logs:PutLogEvents
Effect: Allow
Resource:
- !Sub arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/lambda/${lambdaFunctionName}:*
PolicyName: cloudWatchLogs
Tags:
-
Key: Project
Value: test
lambdaLogGroup:
Type: AWS::Logs::LogGroup
Properties:
LogGroupName: !Sub /aws/lambda/${lambdaFunctionName}
RetentionInDays: 90
Tags:
-
Key: Project
Value: test
############################ Output ############################
Outputs:
apiGatewayInvokeURL:
Value: !Sub https://${apiGateway}.execute-api.${AWS::Region}.amazonaws.com/${apiGatewayStageName}
BucketUrl:
Value: !Sub s3://${application}-${apiGatewayStageName}-${AWS::AccountId}/api_swagger.yml
swagger.yaml
openapi: 3.0.1
info:
title: Label Hub
termsOfService: http://swagger.io/terms/
contact:
email: apiteam#swagger.io
license:
name: Apache 2.0
url: http://www.apache.org/licenses/LICENSE-2.0.html
version: 1.0.0
externalDocs:
description: Find out more about Swagger
url: http://swagger.io
servers:
- url: https://example.labelhub.de/v2
security:
- api_key: []
paths:
/application/rule/bufferZoneList:
get:
tags:
- application
summary: Returns list of buffer zones per field object for drift management
description: Returns a map of status codes to quantities
operationId: getApplicationRuleDrift
parameters:
- name: pName
in: query
required: true
schema:
type: string
- name: cCode
in: query
required: true
schema:
type: string
- name: cType
in: query
required: true
schema:
type: string
- name: nType
in: query
schema:
type: string
- name: timing
in: query
schema:
type: string
- name: rate
in: query
schema:
type: string
responses:
200:
description: successful operation
content:
application/json:
schema:
$ref: '#/components/schemas/bufferZoneList'
x-amazon-apigateway-integration:
type: "aws_proxy"
httpMethod: "POST"
uri:
Fn::Sub: "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${lambdaFunction.Arn}/invocations"
responses:
default:
statusCode: "200"
passthroughBehavior: "when_no_match"
contentHandling: "CONVERT_TO_TEXT"
components:
schemas:
crop:
type: object
properties:
id:
type: integer
format: int64
name:
type: string
cropTypeList:
type: array
items:
$ref: '#/components/schemas/crop'
bufferZone:
type: object
properties:
bufferZone:
type: integer
example: 5
unit:
type: string
example: m
areaType:
type: string
example: WATERBODY_VEGETATED
bufferZoneList:
type: array
items:
$ref: '#/components/schemas/bufferZone'
layout:
required:
- "name"
type: "object"
properties:
id:
type: "integer"
format: "int64"
name:
type: "string"
status:
type: "string"
description: "label layout status in the application"
enum:
- "available"
- "pending"
MODEL444ead:
type: "object"
properties:
file:
type: "string"
description: "file to upload"
format: "binary"
apiResponse:
type: "object"
properties:
code:
type: "integer"
format: "int32"
type:
type: "string"
message:
type: "string"
product:
type: "object"
properties:
id:
type: "integer"
format: "int64"
name:
type: "string"
MODEL6f7c6f:
type: "object"
additionalProperties:
type: "integer"
format: "int32"
securitySchemes:
api_key:
type: "apiKey"
name: "x-api-key"
in: "header"
Any solutions to pass the uri to my swagger file ?

Answer 1

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/create-reusable-transform-function-snippets-and-add-to-your-template-with-aws-include-transform.html
The documentation includes the follow note:
We don't currently support using shorthand notations for YAML snippets.
Instead of
uri: !Sub "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:function:crawler/invocations"
use
uri:
Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${LambdaFunction.Arn}/invocations
!Sub is shorthand notation so won't be supported
Edit:
Issue with swagger.yaml
x-amazon-apigateway-integration:
type: "aws_proxy"
httpMethod: "POST"
uri:
Fn::Sub: "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${lambdaFunction.Arn}/invocations"
responses:
default:
statusCode: "200"
passthroughBehavior: "when_no_match"
contentHandling: "CONVERT_TO_TEXT"
The above is incorrect YAML due to wrong indentation of the Fn::Sub line. Change this to:
x-amazon-apigateway-integration:
type: "aws_proxy"
httpMethod: "POST"
uri:
Fn::Sub: "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${lambdaFunction.Arn}/invocations"
responses:
default:
statusCode: "200"
passthroughBehavior: "when_no_match"
contentHandling: "CONVERT_TO_TEXT"
Issue with template.yaml
Resources:
apiGateway:
Type: AWS::ApiGateway::RestApi
Properties:
EndpointConfiguration:
Types:
- REGIONAL
BodyS3Location:
Bucket: !Sub ${application}-${apiGatewayStageName}-${AWS::AccountId}
Key: api_swagger.yml
Name: !Ref apiGatewayName
Tags:
-
Key: Project
Value: test
should be
Resources:
apiGateway:
Type: AWS::ApiGateway::RestApi
Properties:
EndpointConfiguration:
Types:
- REGIONAL
Body:
Fn::Transform:
Name: AWS::Include
Parameters:
Location: !Sub "s3://{application}-${apiGatewayStageName}-${AWS::AccountId}/api_swagger.yml"
Name: !Ref apiGatewayName
Tags:
-
Key: Project
Value: test
As the very first link of my answer mentions, the include transform is required (and was the basis of my original answer!).
After fixing both these issues, I got a circular dependency issue. Since this is outside the scope of your original question and I did not want to spend time debugging more issues, I did not make any more changes, but here are some resources to help you with that:
https://aws.amazon.com/blogs/infrastructure-and-automation/handling-circular-dependency-errors-in-aws-cloudformation/
Work around circular dependency in AWS CloudFormation