Errors if Django gzip middleware used

[OJFord]

Python Version

3.11

Package Version

2.18.0

Description

[ERROR] UnicodeDecodeError: 'utf-8' codec can't decode byte 0x8b in position 1: invalid start byte
Traceback (most recent call last):
  File "/var/task/app/handlers.py", line 102, in app
    return _real_handler(event, context)
  File "/var/task/apig_wsgi/__init__.py", line 99, in handler
    return response.as_apig_response()
  File "/var/task/apig_wsgi/__init__.py", line 329, in as_apig_response
    response["body"] = self.body.getvalue().decode("utf-8")

Called like:

        from apig_wsgi import make_lambda_handler
        from django.core.wsgi import get_wsgi_application

        application = get_wsgi_application()
        _real_handler = make_lambda_handler(application)

with "django.middleware.gzip.GZipMiddleware", in middleware.

[OJFord]

Ah do we perhaps just need binary_support=False? This is with ALB, so I gather the implicit None there is enabling it.

[adamchainz]

I believe this was fixed in #80 , back in version 2.3.0 (2019-08-19).

You’re not using version 2.18.0 as you report because the source in your traceback does not match. Please check which version you are actually using.

Ah, no, sorry the source does match.

[adamchainz]

I think binary_support=True may fix it, but ideally we would send binary automatically. This method should be returning True, but isn’t:

apig-wsgi/src/apig_wsgi/__init__.py

Lines 276 to 289 in dc22094

	def _should_send_binary(self) -> bool:
	"""
	Determines if binary response should be sent to API Gateway
	"""
	if not self.binary_support:
	return False
	content_type = self._get_content_type()
	if not content_type.startswith(self.non_binary_content_type_prefixes):
	return True
	content_encoding = self._get_content_encoding()
	# Content type is non-binary but the content encoding might be.
	return "gzip" in content_encoding.lower()

[OJFord]

That could be a problem with my headers rather than that detection though I suppose.

I will try it shortly, thanks for getting back to me so quickly.

[OJFord]

It's because of the first

if not self.binary_support:
    return False

isn't it? I'm not setting it, and so:

apig-wsgi/src/apig_wsgi/__init__.py

Lines 74 to 76 in dc22094

	if version in ("1.0", "alb"):
	# Binary support deafults 'off' on version 1
	event_binary_support = binary_support or False

(which seems contrary to the readme, hence I got it the wrong way around in my first reply:

apig-wsgi/README.rst

Line 81 in dc22094

* ALB’s support binary responses by default.

?)

[OJFord]

I think binary_support=True may fix it

and I can confirm it does indeed! Thanks again.

As above though I think the intention was for version == "alb" to do binary_support != False rather than or False, i.e. to default it True when None, so it wouldn't have been necessary for me to set it explicitly.

[adamchainz]

Okay, I just came back to this. I think I fixed it in #528, releasing shortly. Would you be able to check?

[OJFord]

Yep seems fine now without the binary_support=True arg too, thanks!