All responses are base64 encoded

[joeldentici]

It seems that Zappa always responds with a base64 encoded string for the response body and "isBase64Encoded" set to true.

The relevant file is the "handler.py" file provided/generated by Zappa.

On line 513, we have this if statement:

if not response.mimetype.startswith("text/") \
    or response.mimetype != "application/json":

The condition's negation is:

response.mimetype.startswith("text/") and response.mimetype == "application/json"

Clearly this is a contradiction, so the condition itself is a tautology. The true branch is taken and Zappa will always base64 encode responses.

It seems that the intention of the condition is to NOT base64 encode responses that are text (but to take a conservative approach to determine what is "text").

It seems that what we want is to NOT base64 encode when this condition is true:

response.mimetype.startswith('text/') or response.mimetype == 'application/json'

If this is the case, the condition starting on line 513 should instead be:

not response.mimetype.startswith('text/') and response.mimetype != 'application/json'

I noticed this while using Zappa 0.46.2

[erindan]

Worth noting that this encoding bug seemingly makes it impossible to do API Gateway level compression of responses. Perhaps this needs a priority bump?

[55octet]

This seems like a pretty big bug. I was unable to get anything but base64 responses until I disabled binary_support.

[vitodsk]

+1
In my case this problem was preventing to have a normal deployment on AWS using Api Gateway Lambda proxy integration. There was a 40% overhead due to the computation of the encoding/decoding.

[ronenh]

I ran into the same issue and worked around it by adding "binary_support": false to my zappa_settings.json.
I suppose this may not work if any of your API endpoints do in fact return binary content but that wasn't the case for me.

[monkut]

Just want to note that the "Binary Media Types" RestAPI Settings for the ApiGateway if defined as "/" may cause APIGateway to encode incoming request.body to b64.

[monkut]

I put a PR together to work on some of the issues around this. It may only work for my use case though...

#2170