API gateway returns 401 and doesn't invoke custom authorizer - node.js

Question

I've implemented a custom 'REQUEST' type authorizer for an API gateway which validates a JWT token passed in the 'Authorization' header. I've tested the lambda independently and it works as expected. I've also attached the authorizer to my routes and I can test it in the AWS console - again, everything seems to work (see image):
successful invoke via console
However, when I try to invoke my endpoints with the token in the Authorization header, I always receive an UNAUTHORIZED response:
{
"errors": [
{
"category": "ClientError",
"code": "UNAUTHORIZED",
"detail": "Unauthorized",
"method": "GET",
"path": "/cases",
"requestId": "004eb254-a926-45ad-96a5-ce3527621c81",
"retryable": false
}
]
}
From what I have gathered, API gateway never invokes my Authorizer as i don't see any log events in its cloudwatch. I was able to enable cloudwatch logging of my API gateway, and the only log information I see is as follows:
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| timestamp | message |
|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 1578275720543 | (dac0d4f6-1380-4049-bcee-bf776ca78e5c) Extended Request Id: F2v9WFfiIAMF-9w= |
| 1578275720543 | (dac0d4f6-1380-4049-bcee-bf776ca78e5c) Unauthorized request: dac0d4f6-1380-4049-bcee-bf776ca78e5c |
| 1578275720543 | (dac0d4f6-1380-4049-bcee-bf776ca78e5c) Extended Request Id: F2v9WFfiIAMF-9w= |
| 1578275720544 | (dac0d4f6-1380-4049-bcee-bf776ca78e5c) Gateway response type: UNAUTHORIZED with status code: 401 |
| 1578275720544 | (dac0d4f6-1380-4049-bcee-bf776ca78e5c) Gateway response body: {"errors": [{"category": "ClientError","code": "UNAUTHORIZED","detail": "Unauthorized","method": "GET","path": "/cases","requestId": "dac0d4f6-1380-4049-bcee-bf776ca78e5c","retryable": false }]} |
| 1578275720544 | (dac0d4f6-1380-4049-bcee-bf776ca78e5c) Gateway response headers: {} |
| 1578275720544 | (dac0d4f6-1380-4049-bcee-bf776ca78e5c) Gateway response type: UNAUTHORIZED with status code: 401 |
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
At this point I am completely stuck and not sure how to debug this further. I'm assuming something must be configured wrong but the log information I can find doesn't given any indication of what the problem is. I've also pasted a copy of my authorizers configuration in the image below:
Authorizer Configuration
Screenshot of one endpoint configured to use the authorizer

Answer 1

I figured out the problem I was having:
I needed to set identitySource: method.request.header.Authorization in the authorizer field of the endpoint as well as in the CF stack.
Custom Authorizer definition in raw cloudformation:
service:
name: api-base
frameworkVersion: ">=1.2.0 <2.0.0"
plugins:
- serverless-plugin-optimize
- serverless-offline
- serverless-pseudo-parameters
- serverless-domain-manager
custom:
stage: ${self:provider.stage, 'dev'}
serverless-offline:
port: ${env:OFFLINE_PORT, '4000'}
false: false
cognitoStack: marley-auth
customDomain:
domainName: ${env:BE_HOST, ''}
enabled: ${env:EN_CUSTOM_DOMAIN, self:custom.false}
stage: ${self:provider.stage, 'dev'}
createRoute53Record: true
provider:
name: aws
runtime: nodejs10.x
versionFunctions: true
apiName: public
logs:
restApi: true
stackTags:
COMMIT_SHA: ${env:COMMIT_SHA, 'NO-SHA'}
environment:
USER_POOL_ID: ${cf:${self:custom.cognitoStack}-${self:custom.stage}.UserPoolId}
CLIENT_ID: ${cf:${self:custom.cognitoStack}-${self:custom.stage}.UserPoolClientId}
timeout: 30
iamRoleStatements:
- Effect: "Allow"
Action:
- "lambda:InvokeFunction"
Resource: "*"
functions:
authorizer:
handler: handler/authorize.handler
resources:
- Outputs:
ApiGatewayRestApiId:
Value:
Ref: ApiGatewayRestApi
Export:
Name: ${self:custom.stage}-${self:provider.apiName}-ApiGatewayRestApiId
ApiGatewayRestApiRootResourceId:
Value:
Fn::GetAtt:
- ApiGatewayRestApi
- RootResourceId
Export:
Name: ${self:custom.stage}-${self:provider.apiName}-ApiGatewayRestApiRootResourceId
SharedAuthorizerId:
Value:
Ref: SharedAuthorizer
Export:
Name: ${self:custom.stage}-${self:provider.apiName}-ApiGatewaySharedAuthorizerId
- Resources:
SharedAuthorizer:
Type: AWS::ApiGateway::Authorizer
Properties:
Name: public
AuthorizerUri: !Join
- ''
- - 'arn:aws:apigateway:'
- !Ref 'AWS::Region'
- ':lambda:path/2015-03-31/functions/'
- !GetAtt
- AuthorizerLambdaFunction
- Arn
- /invocations
RestApiId: !Ref 'ApiGatewayRestApi'
Type: REQUEST
IdentitySource: method.request.header.Authorization
AuthorizerResultTtlInSeconds: '300'
DependsOn: AuthorizerLambdaFunction
ApiAuthLambdaPermission:
Type: AWS::Lambda::Permission
Properties:
Action: lambda:InvokeFunction
FunctionName: !Ref AuthorizerLambdaFunction
Principal: apigateway.amazonaws.com
SourceArn: !Sub "arn:aws:execute-api:#{AWS::Region}:#{AWS::AccountId}:#{ApiGatewayRestApi}/authorizers/*"
DependsOn: ApiGatewayRestApi
Using the authorizer in another stack - note that I have specified IdentitySource here as well as in the definition of the authorizer - for some reason I had to do it in both places.
authorizer:
type: CUSTOM
authorizerId: ${cf:api-base-${self:custom.stage}.SharedAuthorizerId}
identitySource: method.request.header.Authorization