Serverless-express: Getting a CORS error in the response.

[bansalrachita]

I'm trying to use this module to build a serverless app and stuck at a point where I can't seem to get the response to have CORS header for a GET request.

I tried adding the header manually but doesn't work. Adding the Lambda handler code below.

exports.handler = (event, context) => {

if (event.headers) {
event.headers["Access-Control-Allow-Origin"] = "*";
event.headers["Access-Control-Expose-Headers"] = "Origin";
}

awsServerlessExpress.proxy(server, event, context);
};

In the express app, I have added below,

app.use((req, res, next) => {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Methods", "GET, PUT, POST, DELETE, OPTIONS");
res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With," +
" Content-Type, Accept");
next();
});

Also, I'm using serverless for deploying the app and have enabled cors in the serverless.yml config file.

Does anyone know of a solution to this problem?

[novemberde]

You need to configure on API Gateway enabling CORS. This code just works on Lambda.

[brettstack]

Nothing obviously wrong with that. Have you tried using the Express cors middleware instead?

[bansalrachita]

Thanks! It works with the cors middleware. Wondering why it wouldn't work with the above.

[brettstack]

Not sure but I'm glad it's working now!