I have a AWS Lambda function that is triggered via AWS API Gateway. When I test my function on Lambda it is working. When I send a POST request to the API url via ajax, I get a 502 bad gateway error.
XMLHttpRequest cannot load https://xxxxxxxx.execute-api.us-east-1.amazonaws.com/prod/myLambdaFunction. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'mywebsite.com' is therefore not allowed access. The response had HTTP status code 502.
Obviously this was a CORS issue, so I thought I could change the CORS settings in my AWS API Gateway URL which I did, but I am still getting an error for this.
What do I have to change on AWS side or my own to be able to POST to the URL?
Unfortunately there is a known issue with many classes of 4xx and 5xx errors where CORS headers will not be sent, even if you've added CORS support via the console.
As noted in comments, the CORS error is a side effect of the fact that your API is returning a 502. This often occurs if you are using the LAMBDA_PROXY integration type and are returning invalid JSON from your Lambda function.
Please try either using the test invoke functionality from the console or enable logging in your API to debug further.
I solved that exact same problem by outputting the CORS header myself.
See below - and I hope that'll help.
Teebo
Amazon docs
function respond(context, responseData) {
var response = {
statusCode: 200,
body: JSON.stringify(responseData),
headers: {
"Content-Type": "application/json; charset=utf-8",
"Access-Control-Allow-Origin": "*"
}
};
context.succeed(response); }
Related
I am using google business API and trying to get location list.
I am going trough their documentation and using project from the link below as basis
https://developers.google.com/my-business/content/implement-oauth
Using that project I am able to successfully retrieve accounts list.
The problem occures when I try to retrieve locations list using accountID. Here is a link for their documentation
https://developers.google.com/my-business/content/manage-locations
Acording to documentation, to get location list for specific account, I should use following request
GET
https://mybusinessbusinessinformation.googleapis.com/v1/{accountId}/locations
Authorization: Bearer <access_token>
This is the code snippet, that I added to their sample project
function retrieveGoogleMyBusinessLocations(accessToken) {
$.ajax({
type: 'GET',
url: 'https://mybusinessbusinessinformation.googleapis.com/v1/{accID}/locations',
headers: {
'Authorization' : 'Bearer ' + accessToken
},
success: function(returnedData) {
var e = document.createElement("pre")
e.innerHTML = JSON.stringify(returnedData, undefined, 2);
document.body.appendChild(e);
}
});
}
When I do this request, it gives "CORS error".
The error in the console is following
Access to XMLHttpRequest at 'https://mybusinessbusinessinformation.googleapis.com/v1/xxx/locations' from origin 'http://localhost:8001' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
GET https://mybusinessbusinessinformation.googleapis.com/v1/xxx/locations net::ERR_FAILED
From the error message it seems that server does no accept requests from localhost:8001, but if I do request to different endpoint it will return result.
For example if I change utl from
https://mybusinessbusinessinformation.googleapis.com/v1/{accID}/locations
to
https://mybusinessbusinessinformation.googleapis.com/v1/accounts/{accID}/locations?readMask=categories
With the second url it will return successfull result.
I am confused why it is allowing requests to one endpoint and blocks requests to other endpoint.
Can anyone help with this problem?
Have you tried making direct API requests via the Google Developers OAuth 2.0 Playground?
I tried to reproduce your error but got the expected 404 Not Found response for the unsupported endpoint pattern.
Am getting the following error:
Access to fetch at 'https://...' from origin 'https://...' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
p.s. from blazor wasm web api call
Enabling CORS support for Lambda or HTTP non-proxy integrations and AWS service integrations
For a Lambda custom (non-proxy) integration, HTTP custom (non-proxy) integration, or AWS service integration, you can set up the required headers by using API Gateway method response and integration response settings. When you enable CORS by using the AWS Management Console, API Gateway creates an OPTIONS method and attempts to add the Access-Control-Allow-Origin header to your existing method integration responses.
This doesn’t always work, and sometimes you need to manually modify the integration response to properly enable CORS. Usually this just means manually modifying the integration response to return the Access-Control-Allow-Origin header.
exports.handler = async (event) => {
const response = {
statusCode: 200,
headers: {
"Access-Control-Allow-Headers" : "Content-Type",
"Access-Control-Allow-Origin": "https://www.example.com",
"Access-Control-Allow-Methods": "OPTIONS,POST,GET"
},
body: JSON.stringify('Hello from Lambda!'),
};
return response;
};
Have you tried the following?
make sure to set
Access-Control-Allow-Origin
*
Access-Control-Allow-Headers
*
Access-Control-Allow-Methods
*
p.s.
you may need to make the above more restrictive e.g. to your apps domain
also don't forget to clear your browsers cache
https://console.aws.amazon.com/apigateway/main/develop/cors
I am trying to set up an API Gateway to call another lambda function that will upload an image to S3. The feature works well when I am using an app like POSTMAN, however when I run the browser using React I am getting the following error.
Access to fetch at 'https://.../upload' from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
In my API Gateway I have the following configuration for that method
Gateway Responses for UserUpload API: default 4XX (not checked), default 5XX (not checked)
Methods: post (checked), options (checked)
Access-Control-Allow-Methods: options, post
Access-Control-Allow-Headers: '*'
Access-Control-Allow-Origin: '*'
This API uses an authorizer, I am using the one provided by Auth0 and have not edited the code at all.
And the function that my authorizer calls returns the response like the below (eg happy path):
exports.handler = async (event) => {
//do data checks and upload to s3
return {
headers: {
"Content-Type": "application/json",
"Access-Control-Allow-Methods": "*",
"Access-Control-Allow-Origin": "*",
},
statusCode: 200,
body: JSON.stringify({ message: "success" }),
};
This is my first time setting up both a lambda function, authorisation provider and API Gateway so I might be missing something obvious. I have also tried added mode: no-cors to my fetch POST requests however they still fail in a very similar way.
From what I can tell by looking at the logs of the authorizer and the lambda function that uploads the images, is that they are not even being called. So it appears the CORS error is with the API Gateway.
I have seen in a few tutorials that in their aws template yaml files they add an option AddDefaultAuthorizerToCorsPreflight as False. I can't see this anywhere in the API Gateway console.
Update: I have tested my function with the custom authoriser turned off and it works. So I know that CORS works for the options method, and for the returned request on the lambda function. It is the custom authoriser that is the problem.
The flow is currently:
Method Request - Auth: my-auth-0-authorizer
Integration Request - Type: Lambda_proxy
Lambda function
Integration response - [greyed out Proxy integrations cannot be configured to transform responses]
Method Response: HTTP Status: Proxy (with Access-Control-Allow-Origin in the response headers)
What do I have to do differently or change to allow my authoriser to respect the CORS config?
Update: After leaving my API Gateway for a day, successful responses are now working (using the flow mentioned above). I am not sure if there was a glitch in the system or there was unexpected occurring but it is now working. I am still getting a CORS issue but now only with bad responses.
The custom authoriser fails by return context.fail("Unauthorized"); and when this occurs my browser gets a CORS error. Do I have to set up special gateway responses for 4XX responses?
I am using serverless to deploy my service. This is how i am configuring a lambda function
hello:
handler: handler.hello
events:
- http:
path: /hello
method: get
cors: true
authorizer: aws_iam
Also i am using AWS cognito to authorise logged in user. The same user credentials are working for other serverless services but for this one. we are sending proper response headers as well as mentioned in some other solutions. I have tried almost everything i could find.
This is the error i am getting (Though option call is giving 200).
Access to fetch at 'https://*******.execute-api.us-east-2.amazonaws.com/dev/hello' from origin 'http://***.ngrok.io' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
I would appreciate your help.
Please comment if any other information is required for you to understand my problem.
Thanks a lot.
you should return access-control-allow-Origin from lambda resposne as well.
In python it is something like this
return {'statusCode': status_code,
'body': response,
'isBase64Encoded': False,
'headers':{ 'Access-Control-Allow-Origin': 'http://localhost:3000'}}
more about it here
I've been trying to fix this all day.
I got a Lambda function I'm trying to run when I make a POST request to the endpoint (configured with AWS API GATEWAY).
Everything runs fine, my options gets a 200 okay, my post gets a 200 okay and comes back with the data I want.
However when I get it back, it "thinks" it failed. I use JQuery for this project, and it comes back as the "fail" cb.
Looking at the console log the problem is quite clearly the following error:
XMLHttpRequest cannot load
https://xxxxxxxxx.execute-api.us-west-2.amazonaws.com/prod/createCustomer.
No 'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'http://localhost:3000' is therefore not allowed
access.
a standard CORS issue. But nothing I do seems to work. I enabled CORS on the API gateway (before that the OPTIONS would fail). the 'Access-Control-Allow-Origin': is set to: '*' which should allow access from any origin. I of course deployed the new API.
I also tried not using CORS and instead enabling the AWS proxy thing, and having my response like this { statusCode, headers, body } but when doing that I get no response whatsoever.
I have absolutely no clue where to start attempting to fix this. I even tried a dirty jsonp method. But still same problem. :(
The only bit of data I can find on my request that doesn't seem okay, is this: x-cache:Miss from cloudfront
Here's the full response headers from the POST request:
content-length:2312
content-type:application/json
date:Thu, 23 Mar 2017 22:15:08 GMT
status:200
via:1.1 95a477af435073615179b256d8101334.cloudfront.net (CloudFront)
x-amz-cf-id:Hc6POYFO0HKB1xriSg2iH7O1po7ah926a4dQkgfSNBUZ460RoHRNuw==
x-amzn-requestid:2b5ed745-1016-11e7-b497-cb0a77cd1479
x-amzn-trace-id:Root=1-58d448ea-56717776eaa3f5389083e9ca
x-cache:Miss from cloudfront
Sadly as is quite obvious, the Access control headers aren't there... I assume that's the problem I'm desperately trying to fix. But I have no idea why since I set it to ' * ' during the Enable CORS step of this process.
I was able to get semi-close to a solution by manually creating a POST method (as opposed to "ANY"), then enabling CORS again, then turning on the PROXY on integration response, and set my response to: { statusCode, headers, body } This will come back as a successfull event and run the right callback function in my ajax call. However, using this method I get no data back from Lambda... despite having it in "body", all I receive is an empty object.
I don't really have a preference of using CORS or manually adding headers, that's fine I won't be updating this much. I just really really need to get it functioning :( Any help would be greatly appreciated.
If you got x-cache:Miss from cloudfront from your API, it is fine because API Gateway doesn't enable the edge cache on the cloudfront side. If you want CORS to work with Lambda proxy integration, you can return the status code and the headers, like,
{
"statusCode": 200,
"headers": { "Access-Control-Allow-Origin": "<domains you need>" }
}
Then, it will be like an empty response from the client side.
I have now idea why, but I was able to get it working. Using the following steps:
Enable CORS,
Deploy API, (can probably be skipped...)
Manually add POST method,
Enable Proxy on Integration response,
Deploy API again
change callback response to format: { statusCode: 200, headers: {}, body: {} }
use JSON.parse() to parse your payload.
This is definitely not a perfect answer. For some reason turning on the Proxy modified how my Lambda function received data, so I had to Stringify it to not cause an error. I can't offer an explanation why this happened.
The headers I used were:
"Access-Control-Allow-Methods": "DELETE,GET,HEAD,OPTIONS,PATCH,POST,PUT",
"Access-Control-Allow-Origin": "*"
A better solution to this would also be a way to do this just using CORS. As you don't have to manually insert headers in all your responses. But I couldn't get that working. So please, if someone knows a better solution to this post it!