AWS CDK user pool authorizer

Question

I'm trying to create an API gateway using the AWS-CDK and protect the REST endpoints with a Cognito user pool authorizer.

I cannot find any examples how one would do this. I thought it should look something like this but maybe the methods I need do not exist?

const cdk       = require('@aws-cdk/cdk');
const lambda    = require('@aws-cdk/aws-lambda');
const apigw     = require('@aws-cdk/aws-apigateway');

const path  = require('path');

// 
// Define the stack:
class MyStack extends cdk.Stack {
    constructor (parent, id, props) {
        super(parent, id, props);    

        var tmethodHandler = new lambda.Function(this, 'test-lambda', {
            runtime: lambda.Runtime.NodeJS810,
            handler: 'index.handler',
            code: lambda.Code.directory( path.join( __dirname, 'lambda')),
        });

        var api         = new apigw.RestApi(this, 'test-api');

        const tmethod   = api.root.addResource('testmethod');

        const tmethodIntegration    = new apigw.LambdaIntegration(tmethodHandler);

        tmethod.addMethod('GET', getSessionIntegration, {
            authorizationType: apigw.AuthorizationType.Cognito,
            authorizerId : 'crap!!!?'
        });

    }
}

class MyApp extends cdk.App {
    constructor (argv) {
        super(argv);

        new MyStack(this, 'test-apigw');
    }
}

console.log(new MyApp(process.argv).run());

Answer 1

As of September 2019 @bgdnip answer doesnt translate exactly for typescript. I got it working with the following:

const api = new RestApi(this, 'RestAPI', {
    restApiName: 'Rest-Name',
    description: 'API for journey services.',
});

const putIntegration = new LambdaIntegration(handler);

const auth = new CfnAuthorizer(this, 'APIGatewayAuthorizer', {
    name: 'customer-authorizer',
    identitySource: 'method.request.header.Authorization',
    providerArns: [providerArn.valueAsString],
    restApiId: api.restApiId,
    type: AuthorizationType.COGNITO,
});

const post = api.root.addMethod('PUT', putIntegration, { authorizationType: AuthorizationType.COGNITO });
const postMethod = post.node.defaultChild as CfnMethod;
postMethod.addOverride('Properties.AuthorizerId', { Ref: auth.logicalId });

This is from https://docs.aws.amazon.com/cdk/latest/guide/cfn_layer.html#cfn_layer_resource_props

UPDATE October

The above is already out of date and unnecessary and can be achieved with the following with aws-cdk 1.12.0

const api = new RestApi(this, 'RestAPI', {
    restApiName: 'Rest-Name',
    description: 'API for journey services.',
});

const putIntegration = new LambdaIntegration(handler);

const auth = new CfnAuthorizer(this, 'APIGatewayAuthorizer', {
    name: 'customer-authorizer',
    identitySource: 'method.request.header.Authorization',
    providerArns: [providerArn.valueAsString],
    restApiId: api.restApiId,
    type: AuthorizationType.COGNITO,
});

const post = api.root.addMethod('PUT', putIntegration, {
    authorizationType: AuthorizationType.COGNITO,
    authorizer: { authorizerId: auth.ref }
});

Answer 2

The previous answers no longer work because the authorizerId property was replaced with authorizer, which isn't fully implemented at this time.

Instead, it can be done by using the underlying CfnResource objects, as described in the official guide.

Here's Python code as an example:

from aws_cdk import cdk
from aws_cdk import aws_apigateway


class Stk(cdk.Stack):
    def __init__(self, app, id):
        super().__init__(app, id)

        api_gw = aws_apigateway.RestApi(self, 'MyApp')
        post_method = api_gw.root.add_method(http_method='POST')

        # Create authorizer using low level CfnResource
        api_gw_authorizer = aws_apigateway.CfnAuthorizer(
            scope=self,
            id='my_authorizer',
            rest_api_id=api_gw.rest_api_id,
            name='MyAuth',
            type='COGNITO_USER_POOLS',
            identity_source='method.request.header.name.Authorization',
            provider_arns=[
                'arn:aws:cognito-idp:eu-west-1:123456789012:userpool/'
                'eu-west-1_MyCognito'])

        # Get underlying post_method Resource object. Returns CfnMethod
        post_method_resource = post_method.node.find_child('Resource')
        # Add properties to low level resource
        post_method_resource.add_property_override('AuthorizationType',
                                                   'COGNITO_USER_POOLS')
        # AuthorizedId uses Ref, simulate with a dictionaty
        post_method_resource.add_property_override(
                'AuthorizerId',
                {"Ref": api_gw_authorizer.logical_id})


app = cdk.App()
stk = Stk(app, "myStack")

app.synth()