I am experimenting with an AWS API-Gateway integration with an S3 backend. I have noticed the switch between different mapping-templates in the integration-response does not appear to work.
In integration-response, I have the following mapping templates:
application/json:
{
type: "JSON",
body: "$input.body"
}
text/plain:
PlainText:
$input.body
Nothing I can do appears to be able to make the text/plain mapping template to be used - it always uses application/json.
I would expect that the text/plain mapping template to be used based on one of the following being true:
S3 returns content with Content-Type: text/plain.
The initial request to API-Gateway passes an Accept: text/plain header.
As per the example below, S3 returns a Content-Type: text/plain AND I request with Accept: text/plain. API-Gateway correctly responds with Content-Type: text/plain also.
However the application/json template is still used to transform the body.
I have even removed application/json as a valid response type from the method-response entirely, but still nothing.
Any thoughts why this is happening?
FYI I am using a classic v1 ApiGateway (Rest).
Execution log for request c24cfce3-2cf3-4693-ad72-4fdf44f4fdcd
Wed May 19 17:13:38 UTC 2021 : Starting execution for request: c24cfce3-2cf3-4693-ad72-4fdf44f4fdcd
Wed May 19 17:13:38 UTC 2021 : HTTP Method: GET, Resource Path: /feeds-poc/test.txt
Wed May 19 17:13:38 UTC 2021 : Method request path: {filename=test.txt}
Wed May 19 17:13:38 UTC 2021 : Method request query string: {}
Wed May 19 17:13:38 UTC 2021 : Method request headers: {Accept=text/plain}
Wed May 19 17:13:38 UTC 2021 : Method request body before transformations:
Wed May 19 17:13:38 UTC 2021 : Endpoint request URI: https://my-bucket-id.s3.eu-west-1.amazonaws.com/test.txt
Wed May 19 17:13:38 UTC 2021 : Endpoint request headers: {Authorization=****57173a, X-Amz-Date=20210519T171338Z, x-amzn-apigateway-api-id=123456789a, Accept=application/json, User-Agent=AmazonAPIGateway_123456789a, X-Amz-Security-Token=**** [TRUNCATED]
Wed May 19 17:13:38 UTC 2021 : Endpoint request body after transformations:
Wed May 19 17:13:38 UTC 2021 : Sending request to https://my-bucket-id.s3.eu-west-1.amazonaws.com/test.txt
Wed May 19 17:13:38 UTC 2021 : Received response. Status: 200, Integration latency: 43 ms
Wed May 19 17:13:38 UTC 2021 : Endpoint response headers: {x-amz-id-2=****, x-amz-request-id=****, Date=Wed, 19 May 2021 17:13:39 GMT, Last-Modified=Mon, 17 May 2021 16:45:13 GMT, ETag="420f804aa21220bf0db57bb4b9799c8a", Accept-Ranges=bytes, Content-Type=text/plain, Content-Length=13, Server=AmazonS3}
Wed May 19 17:13:38 UTC 2021 : Endpoint response body before transformations: It's working
Wed May 19 17:13:38 UTC 2021 : Method response body after transformations: {
type: "JSON",
body: "It's working
"
}
Wed May 19 17:13:38 UTC 2021 : Method response headers: {X-Amzn-Trace-Id=Root=****, Content-Type=text/plain}
Wed May 19 17:13:38 UTC 2021 : Successfully completed execution
Wed May 19 17:13:38 UTC 2021 : Method completed with status: 200
AWS Support confirmed to me that the switch is based on the original request Accept header. Testing this using Postman confirms this functionality.
The test tools built into the AWS console for API-Gateway however do not appear to cater for testing response mapping templates - from AWS support: the purpose of API Gateway test console is only to test the Integration, it doesn't work for end-to-end request.
I'm trying to use delete bucket replication operation in Amazon s3 using rest API [1]. For this, I have implemented the AWS signature calculation class[2] and a method to call the deleteBucketReplication rest API [3]. But I'm getting 403 "SignatureDoesNotMatch" error. Please find the request sending to backed here [4].
Can anyone help me to overcome this issue?
[1] https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketDELETEreplication.html
[2] https://github.com/Biruntha/AWS_S3_Example/blob/master/src/main/java/AWSSignatureV4Generator.java
[3]https://github.com/Biruntha/AWS_S3_Example/blob/master/src/main/java/AWSV4AuthTest.java#L13
[4]
Canonical Request: DELETE
/?replication
host:testbuckkkbiru.s3.amazonaws.com
x-amz-content-sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
x-amz-date:Tue, 09 Oct 2018 05:55:08 GMT
host;x-amz-content-sha256;x-amz-date
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
String to sign: AWS4-HMAC-SHA256
Tue, 09 Oct 2018 05:55:08 GMT
20181009/us-east-2/s3/aws4_request
d9c53b745da19f10565cf77b6b11fde944354448322b85d99b7f502a363fb57e
Signature:
e29af9cf031ac2c94a109f20fa9f8ad5b88b89686f86e32015c8b535b84fcc46
Header:
x-amz-date = Tue, 09 Oct 2018 05:55:08 GMT
Authorization = AWS4-HMAC-SHA256
Credential=xxxxxxxxxxxxxx/20181009/us-east-2/s3/aws4_request,SignedHeaders=host;x-amz-content-sha256;x-amz-date,Signature=e29af9cf031ac2c94a109f20fa9f8ad5b88b89686f86e32015c8b535b84fcc46
================================
I have a Java based Lambda function that is running correctly via the Lambda test event with the following JSON:
{
"married": "true",
"wages": "200000",
"homeInterest": "15000",
"propertyTaxes": "15000",
"stateTaxes": "13000",
"otherDeductions": "4000",
"postalCode": "11762"
}
I then created an API via the Amazon API Gateway. When I paste the same JSON as the body of the generated URL none of fields map correctly.
The Lambda handler is using POJOs for the request and response:
public class TaxHandler implements RequestHandler<TaxRequest, TaxResponse>{
public TaxResponse handleRequest(TaxRequest request, Context context){
When I test via the API gateway test I see the following info:
Execution log for request test-request
Tue Dec 19 02:01:16 UTC 2017 : Starting execution for request: test-invoke-request
Tue Dec 19 02:01:16 UTC 2017 : HTTP Method: POST, Resource Path: /TaxCalculation
Tue Dec 19 02:01:16 UTC 2017 : Method request path: {}
Tue Dec 19 02:01:16 UTC 2017 : Method request query string: {}
Tue Dec 19 02:01:16 UTC 2017 : Method request headers: {}
Tue Dec 19 02:01:16 UTC 2017 : Method request body before transformations: {
"married": "true",
"wages": "200000",
"homeInterest": "15000",
"propertyTaxes": "15000",
"stateTaxes": "13000",
"otherDeductions": "4000",
"postalCode": "11762"
}
Tue Dec 19 02:01:16 UTC 2017 : Endpoint request URI: https://lambda.us-east-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:us-east-1:896795400074:function:TaxCalculation/invocations
Tue Dec 19 02:01:16 UTC 2017 : Endpoint request headers: {x-amzn-lambda-integration-tag=test-request, Authorization=************************************************************************************************************************************************************************************************************************************************************************************************************************7fcbc9, X-Amz-Date=20171219T020116Z, x-amzn-apigateway-api-id=07yp3njqzk, X-Amz-Source-Arn=arn:aws:execute-api:us-east-1:896795400074:07yp3njqzk/null/POST/TaxCalculation, Accept=application/json, User-Agent=AmazonAPIGateway_07yp3njqzk, X-Amz-Security-Token= [TRUNCATED]
Tue Dec 19 02:01:16 UTC 2017 : Endpoint request body after transformations: {"resource":"/TaxCalculation","path":"/TaxCalculation","httpMethod":"POST","headers":null,"queryStringParameters":null,"pathParameters":null,"stageVariables":null,"requestContext":{"path":"/TaxCalculation","accountId":"xxxxxxxx","resourceId":"v8358d","stage":"test-invoke-stage","requestId":"test-invoke-request","identity":{"cognitoIdentityPoolId":null,"cognitoIdentityId":null,"apiKey":"test-invoke-api-key","cognitoAuthenticationType":null,"userArn":"arn:aws:iam::xxxxx:user/tvfoodmaps_aws","apiKeyId":"test-invoke-api-key-id","userAgent":"Apache-HttpClient/4.5.x (Java/1.8.0_144)","accountId":"896795400074","caller":"AIDAINMSXKH5AWAQ7NX36","sourceIp":"test-invoke-source-ip","accessKey":"ASIAIHXWW4BOHGXESRNQ","cognitoAuthenticationProvider":null,"user":"AIDAINMSXKH5AWAQ7NX36"},"resourcePath":"/TaxCalculation","httpMethod":"POST","apiId":"07yp3njqzk"},"body":"{\n \"married\": \"true\",\n \"wages\": \"200000\",\n \"homeInterest\": \"15000\",\n \"propertyTa [TRUNCATED]
Tue Dec 19 02:01:16 UTC 2017 : Sending request to https://lambda.us-east-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:us-east-1:896795400074:function:TaxCalculation/invocations
Tue Dec 19 02:01:16 UTC 2017 : Received response. Integration latency: 30 ms
Tue Dec 19 02:01:16 UTC 2017 : Endpoint response body before transformations: {"savings":565.0,"owedTaxes17":-635.0,"owedTaxes18":-1200.0,"effectiveRate17":0.0,"effectiveRate18":0.0}
Tue Dec 19 02:01:16 UTC 2017 : Endpoint response headers: {X-Amz-Executed-Version=$LATEST, x-amzn-Remapped-Content-Length=0, Connection=keep-alive, x-amzn-RequestId=7f8a1b13-e460-11e7-84cf-d1c3e8d3eaf5, Content-Length=104, Date=Tue, 19 Dec 2017 02:01:16 GMT, X-Amzn-Trace-Id=root=1-5a3872ec-1b9d875d8cc2fded5c30da46;sampled=0, Content-Type=application/json}
Tue Dec 19 02:01:16 UTC 2017 : Execution failed due to configuration error: Malformed Lambda proxy response
Tue Dec 19 02:01:16 UTC 2017 : Method completed with status: 502
How can I further debug why the function is not executing the same when called via REST instead of directly via the Lambda tester? Note: I know the error talks about the response but the issue is that the first line of my code reading the fields that should be mapped to the pojo aren't working (again, only when using the API).
Looks like you have your integration with ANY and not returning the proxy response. Instead you are returning the JSON object response.
Similar problem discussed here,
https://forums.aws.amazon.com/thread.jspa?threadID=255561
And the solution to configure is documented here,
https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-set-up-simple-proxy.html#api-gateway-simple-proxy-for-lambda-output-format
Hope it helps.
You can include logging in your code so that they will be available in AWS CloudWatch to investigate the issue. Following libraries and approaches are recommended by AWS according to the documentation for Java.
Custom Appender for Log4j™ 2
LambdaLogger.log(): Example 2: Writing Logs Using LambdaLogger (Java)
System.out() and System.err()
Note: Also setup API Gateway logging so that it would be easier to trace any issue end to end.
My current stack is AWS API Gateway --> AWS Lambda --> swagger-node + swagger-express-mw + aws-serverless-express.
So my Swagger API is hosted as one node.js Lambda Function and Invoked with aws_proxy from API Gateway. This works quite good. The only thing is that when the function sleeped for too long (cold start?) I get a Cannot GET / as Output from every URL I am calling first. From 2nd Request on, it runs very fast. Any ideas on that?
I don't think that it comes from API Gateway Integration Timeout as that are 30 seconds. The slowest invocation time of the function directly via lambda is around 2,5s and when it is called more often it is normally not more than 150ms. I also increased the Time of Lambda Timeout for that function to 10s so from there should also not come an error.
Logs from Test Request via API Gateway first Invocation
Response Body
Cannot GET /hello
Response Headers
{
"x-powered-by": "Express",
"x-content-type-options": "nosniff",
"content-type": "text/html; charset=utf-8",
"content-length": "18",
"date": "Sun, 19 Feb 2017 15:00:11 GMT",
"connection": "close",
"X-Amzn-Trace-Id": "<TRACE-ID>"
}
Logs
Execution log for request test-request
Sun Feb 19 15:00:07 UTC 2017 : Starting execution for request: test-invoke-request
Sun Feb 19 15:00:07 UTC 2017 : HTTP Method: GET, Resource Path: /hello
Sun Feb 19 15:00:07 UTC 2017 : Method request path: {}
Sun Feb 19 15:00:07 UTC 2017 : Method request query string: {}
Sun Feb 19 15:00:07 UTC 2017 : Method request headers: {}
Sun Feb 19 15:00:07 UTC 2017 : Method request body before transformations:
Sun Feb 19 15:00:07 UTC 2017 : Endpoint request URI: https://lambda.eu-central-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:eu-central-1:<ACCOUNT-ID>:function:api/invocations
Sun Feb 19 15:00:07 UTC 2017 : Endpoint request headers: {x-amzn-lambda-integration-tag=test-request, Authorization=**************************************************************************************************************************************************************************************************************************************************************************************************************************4b0637, X-Amz-Date=20170219T150007Z, x-amzn-apigateway-api-id=965h04axki, Accept=application/json, User-Agent=AmazonAPIGateway_965h04axki, X-Amz-Security-Token=<SECURITY-TOKEN>
Sun Feb 19 15:00:07 UTC 2017 : Endpoint request body after transformations: {"resource":"/hello","path":"/hello","httpMethod":"GET","headers":null,"queryStringParameters":null,"pathParameters":null,"stageVariables":null,"requestContext":{"accountId":"<ACCOUNT-ID>","resourceId":"ll6gw8","stage":"test-invoke-stage","requestId":"test-invoke-request","identity":{"cognitoIdentityPoolId":null,"accountId":"<ACCOUNT-ID>","cognitoIdentityId":null,"caller":"<ACCOUNT-ID>","apiKey":"test-invoke-api-key","sourceIp":"test-invoke-source-ip","accessKey":"<ACCESS-ID>","cognitoAuthenticationType":null,"cognitoAuthenticationProvider":null,"userArn":"arn:aws:iam::<ACCOUNT-ID>:root","userAgent":"Apache-HttpClient/4.5.x (Java/1.8.0_102)","user":"<ACCOUNT-ID>"},"resourcePath":"/hello","httpMethod":"GET","apiId":"965h04axki"},"body":null,"isBase64Encoded":false}
Sun Feb 19 15:00:11 UTC 2017 : Endpoint response body before transformations: {"statusCode":404,"body":"Cannot GET /hello\n","headers":{"x-powered-by":"Express","x-content-type-options":"nosniff","content-type":"text/html; charset=utf-8","content-length":"18","date":"Sun, 19 Feb 2017 15:00:11 GMT","connection":"close"},"isBase64Encoded":false}
Sun Feb 19 15:00:11 UTC 2017 : Endpoint response headers: {x-amzn-Remapped-Content-Length=0, x-amzn-RequestId=19f8554e-f6b4-11e6-8184-d3ccf0ccf643, Connection=keep-alive, Content-Length=267, Date=Sun, 19 Feb 2017 15:00:11 GMT, Content-Type=application/json}
Sun Feb 19 15:00:11 UTC 2017 : Method response body after transformations: Cannot GET /hello
Sun Feb 19 15:00:11 UTC 2017 : Method response headers: {x-powered-by=Express, x-content-type-options=nosniff, content-type=text/html; charset=utf-8, content-length=18, date=Sun, 19 Feb 2017 15:00:11 GMT, connection=close, X-Amzn-Trace-Id=Root=1-58a9b2f7-91fc7371e41d6ae9c2fbf64d}
Sun Feb 19 15:00:11 UTC 2017 : Successfully completed execution
Sun Feb 19 15:00:11 UTC 2017 : Method completed with status: 404
Logs from Test Request via API Gateway second Invocation
Response Body
"Hello, stranger!"
Response Headers
{
"x-powered-by": "Express",
"access-control-allow-origin": "*",
"content-type": "application/json; charset=utf-8",
"content-length": "18",
"etag": "W/\"12-E1p7iNXxJ4trMdmFBhlU9Q\"",
"date": "Mon, 13 Feb 2017 20:12:36 GMT",
"connection": "close",
"X-Amzn-Trace-Id": "<Trace-ID>"
}
Logs
Execution log for request test-request
Mon Feb 13 20:12:36 UTC 2017 : Starting execution for request: test-invoke-request
Mon Feb 13 20:12:36 UTC 2017 : HTTP Method: GET, Resource Path: /hello
Mon Feb 13 20:12:36 UTC 2017 : Method request path: {}
Mon Feb 13 20:12:36 UTC 2017 : Method request query string: {}
Mon Feb 13 20:12:36 UTC 2017 : Method request headers: {}
Mon Feb 13 20:12:36 UTC 2017 : Method request body before transformations:
Mon Feb 13 20:12:36 UTC 2017 : Endpoint request URI: https://lambda.eu-central-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:eu-central-1:<LAMBDA-FUNCTION-ID>:function:api/invocations
Mon Feb 13 20:12:36 UTC 2017 : Endpoint request headers: {x-amzn-lambda-integration-tag=test-request, Authorization=*******************************************************************************************************************************************************************************************************************************************************************************************************************************************3e1b18, X-Amz-Date=20170213T201236Z, x-amzn-apigateway-api-id=965h04axki, X-Amz-Source-Arn=arn:aws:execute-api:eu-central-1:<ACCOUNT-ID>:965h04axki/null/GET/hello, Accept=application/json, User-Agent=AmazonAPIGateway_965h04axki, X-Amz-Security-Token=<TOKEN>
Mon Feb 13 20:12:36 UTC 2017 : Endpoint request body after transformations: {"resource":"/hello","path":"/hello","httpMethod":"GET","headers":null,"queryStringParameters":null,"pathParameters":null,"stageVariables":null,"requestContext":{"accountId":"<ACCOUNT-ID>","resourceId":"ll6gw8","stage":"test-invoke-stage","requestId":"test-invoke-request","identity":{"cognitoIdentityPoolId":null,"accountId":"<ACCOUNT-ID>","cognitoIdentityId":null,"caller":"427402682812","apiKey":"test-invoke-api-key","sourceIp":"test-invoke-source-ip","accessKey":"<ACCESS-KEY>","cognitoAuthenticationType":null,"cognitoAuthenticationProvider":null,"userArn":"arn:aws:iam::<ACCOUNT-ID>:root","userAgent":"Apache-HttpClient/4.5.x (Java/1.8.0_102)","user":"<ACCOUNT-ID>"},"resourcePath":"/hello","httpMethod":"GET","apiId":"965h04axki"},"body":null,"isBase64Encoded":false}
Mon Feb 13 20:12:36 UTC 2017 : Endpoint response body before transformations: {"statusCode":200,"body":"\"Hello, stranger!\"","headers":{"x-powered-by":"Express","access-control-allow-origin":"*","content-type":"application/json; charset=utf-8","content-length":"18","etag":"W/\"12-E1p7iNXxJ4trMdmFBhlU9Q\"","date":"Mon, 13 Feb 2017 20:12:36 GMT","connection":"close"},"isBase64Encoded":false}
Mon Feb 13 20:12:36 UTC 2017 : Endpoint response headers: {x-amzn-Remapped-Content-Length=0, x-amzn-RequestId=c3354327-f228-11e6-8c1d-ed11cc413770, Connection=keep-alive, Content-Length=315, Date=Mon, 13 Feb 2017 20:12:36 GMT, Content-Type=application/json}
Mon Feb 13 20:12:36 UTC 2017 : Method response body after transformations: "Hello, stranger!"
Mon Feb 13 20:12:36 UTC 2017 : Method response headers: {x-powered-by=Express, access-control-allow-origin=*, content-type=application/json; charset=utf-8, content-length=18, etag=W/"12-E1p7iNXxJ4trMdmFBhlU9Q", date=Mon, 13 Feb 2017 20:12:36 GMT, connection=close, X-Amzn-Trace-Id=Root=1-58a21334-8ea6c4b5944eebb873bc7d2e}
Mon Feb 13 20:12:36 UTC 2017 : Successfully completed execution
Mon Feb 13 20:12:36 UTC 2017 : Method completed with status: 200
I think the response "Cannot GET /" is coming from your Lambda function itself. Can you check API Gateway CW logs (or Test Invoke feature in console) to see what's different in the integration request and response in the first call?
I didn't see any real documentation about it (just this Medium post) but I also experienced the fact that a Lambda can be frozen until the first invocation, or in the case it's not called for a long time.
A solution is to schedule a regular invocation to wake up your lambda, with Amazon CloudWatch Events
I know that is an old question, but if you use TypeORM (or more in general, if you wrap all your Express middlewares within a .then() callback of a Promise), and you use context.callbackWaitsForEmptyEventLoop = false in your lambda handler, maybe this could help you: https://github.com/typeorm/typeorm/issues/5894
Long story short: avoid to set that flag to false, if possible, otherwise avoid to wrap the Express middlewares within the .then() callback and, for instance, initialize your db connection in the first Express middleware.