Serverless-express: Response has undefined headers - Internal Server Error

[seawatts]

There is something happening between SERVERLESS_EXPRESS:FORWARD_RESPONSE:EVENT_SOURCE_RESPONSE and SERVERLESS_EXPRESS:FORWARD_RESPONSE:CONTENT_TYPE and SERVERLESS_EXPRESS:FORWARD_RESPONSE:HTTP_RESPONSE

The output back to the browser is

{
  "message": "Internal Server Error"
}

Debug Logs

2021-01-27T18:03:30.694Z e3cc35a9-58cb-433f-84bc-2e721658613d DEBUG {
message: 'SERVERLESS_EXPRESS:FORWARD_RESPONSE:EVENT_SOURCE_RESPONSE',
successResponse: {
statusCode: 302,
body: '',
headers: [Object: null prototype] {
vary: 'Origin',
'access-control-allow-credentials': 'true',
'x-dns-prefetch-control': 'off',
'expect-ct': 'max-age=0',
'x-frame-options': 'SAMEORIGIN',
'strict-transport-security': 'max-age=15552000; includeSubDomains',
'x-download-options': 'noopen',
'x-content-type-options': 'nosniff',
'x-permitted-cross-domain-policies': 'none',
'referrer-policy': 'same-origin',
'x-xss-protection': '0',
'set-cookie': [Array],
location: 'https://myapp.ai/
},
isBase64Encoded: false
}
}

2021-01-27T18:03:30.694Z e3cc35a9-58cb-433f-84bc-2e721658613d DEBUG {
message: 'SERVERLESS_EXPRESS:FORWARD_RESPONSE:CONTENT_TYPE',
contentType: ''
}

2021-01-27T18:03:30.694Z e3cc35a9-58cb-433f-84bc-2e721658613d DEBUG {
message: 'SERVERLESS_EXPRESS:FORWARD_RESPONSE:HTTP_RESPONSE',
headers: undefined,
statusCode: 302
}

[brett-vendia]

I'll take a look. Is the 302 expected? What event source is this?

[seawatts]

Yes, I'm just trying to send a redirect with a location header.

What do you mean by this? What event source is this?

[brett-vendia]

By event source I mean are you using API Gateway (V1 or V2?) or something else (Lambda@Edge)

[seawatts]

Oh, API Gateway V2

[brettstack]

That log info was incorrect. I've published @vendia/[email protected] which includes the actual headers that are used in the response. That might give more info? I'll try a 302 redirect myself later.

[brettstack]

Redirect works for me... Here's what my final log looks like:

{
  message: 'SERVERLESS_EXPRESS:FORWARD_RESPONSE:EVENT_SOURCE_RESPONSE',
  successResponse: {
    statusCode: 302,
    body: '<p>Found. Redirecting to <a href="/sam">/sam</a></p>',
    headers: [Object: null prototype] {
      'x-powered-by': 'Express',
      'access-control-allow-origin': '*',
      location: '/sam',
      vary: 'Accept, Accept-Encoding',
      'content-type': 'text/html; charset=utf-8',
      'content-length': '52'
    },
    isBase64Encoded: false
  }
}

[WarFox]

Thanks @brettstack, redirection is working with rc.10, also other headers are working as well.
However there seems to be an issue with setting cookies with api-gateway-v2. Will create an issue for that

[seawatts]

Thanks @brettstack the logs seem to look better. However, I'm still getting the message

{
  "message": "Internal Server Error"
}

So I'm thinking it might be happening somewhere in my stack. But it's pretty suspicious because I don't see any other errors anywhere. I am also setting cookies so I'm curious if it's something to do with what @WarFox is talking about?

[WarFox]

Sounds like it's a similar problem. I have added separate issue for cookie here #355

[seawatts]

Thanks @WarFox!

I'm looking deeper now and it looks like at some point the response is turning into a base64 encoded body. And setting isBase64Encoded to true. Not sure if API Gateway V2 has anything special it needs to do for that or if it can handle it.

[seawatts]

Nevermind, looking at the AWS Docs setting isBase64Encoded to true should be fine.

[brett-vendia]

Shall we close this in favour of 355?