[Geethree]

TL;DR

As noted #662. When running in python2.7 when requesting an endpoint, wsgi returns:

prometheus_1  | Traceback (most recent call last):
prometheus_1  |   File "/usr/local/lib/python2.7/wsgiref/handlers.py", line 85, in run
prometheus_1  |     self.result = application(self.environ, self.start_response)
prometheus_1  |   File "/usr/local/lib/python2.7/site-packages/prometheus_client/exposition.py", line 125, in prometheus_app
prometheus_1  |     start_response(status, [header])
prometheus_1  |   File "/usr/local/lib/python2.7/wsgiref/handlers.py", line 173, in start_response
prometheus_1  |     assert type(status) is StringType,"Status must be a string"
prometheus_1  | AssertionError: Status must be a string

This is reproduced here: https://github.com/Geethree/prometheus-py27-string-bug

I'm not really sure of:

• If this is really the best way to get around this issue, happy to chat about it!
• The best way to construct a test to catch the AssertionError in the Daemon thread, happy to modify if someone can toss me a few tips I'd be happy to write some tests =)

[Geethree]

@csmarchbanks @Travis-Sun =)

[csmarchbanks]

Thank you for the fix! One comment, I am wondering if headers should also be cast as str, which is not happening on 119.

Would you be willing to add a test for this?

[csmarchbanks]

I wonder if lines 118 and 119 should just be cast as str similar to what the end of _bake_output does? Do you only see this issue for requests going to /favicon.ico or other locations as well?

[csmarchbanks]

I ended up fixing this in a slightly different spot with #715, as well as casting the headers as strings which were also causing an exception. Thank you very much for the reproduction and start of a fix though!