Dashboard not being show due to CORS problems

[acorbi]

Steps to reproduce

1. Head to https://pp.opendevelopmentmyanmar.net/dashboards/myanmar-data/

Expected behaviour

The dashboard and data visualizations should show up

Observed behaviour

They do not show up and following error is to be found on the Browser's javascript console

Looking at CKAN's log, following error could be identified:

Traceback (most recent call last):
  File "./ckan/config/middleware/__init__.py", line 136, in __call__
    return self.apps[app_name](environ, start_response)
  File "/usr/local/lib/python2.7/dist-packages/paste/cascade.py", line 130, in __call__
    return self.apps[-1](environ, start_response)
  File "./ckan/config/middleware/common_middleware.py", line 61, in __call__
    return self.app(environ, start_response)
  File "/usr/local/lib/python2.7/dist-packages/paste/registry.py", line 379, in __call__
    app_iter = self.application(environ, start_response)
  File "/usr/local/lib/python2.7/dist-packages/repoze/who/middleware.py", line 117, in __call__
    wrapper.finish_response(remember_headers)
  File "/usr/local/lib/python2.7/dist-packages/repoze/who/middleware.py", line 181, in finish_response
    write = self.start_response(self.status, headers, self.exc_info)
TypeError: http header key must be a string

By outputting the headers on the log, following list of headers was observed:

Alex Corbi, [22.12.17 16:24]
[('Pragma', 'no-cache'), ('Cache-Control', 'no-cache'), ('Content-Type', 'application/json;charset=utf-8'), ('Content-Length', '29517'), (u'Access-Control-Allow-Origin', u'*'), (u'Access-Control-Allow-Methods', u'POST, PUT, GET, DELETE, OPTIONS'), (u'Access-Control-Allow-Headers', u'X-CKAN-API-KEY, Authorization, Content-Type')]

With these 2 pieces of information, the solution seems to convert those unicode strings to normal strings (without u'')

In order to test this, I have set the headers manually on File "/usr/local/lib/python2.7/dist-packages/repoze/who/middleware.py", line 181, in finish_response, like this:

test_headers = [('Pragma', 'no-cache'), ('Cache-Control', 'no-cache'), ('Content-Type', 'application/json;charset=utf-8'), ('Content-Length', '29517'), ('Access-Control-Allow-Origin', '*'), ('Access-Control-Allow-Methods', 'POST, PUT, GET, DELETE, OPTIONS'), ('Access-Control-Allow-Headers', 'X-CKAN-API-KEY, Authorization, Content-Type')]
write = self.start_response(self.status, test_headers, self.exc_info)

which fixes the issue. However this is not a clean solution since it would affect other requests...

[acorbi]

@DragonVirus can you please help identifying a potential fix for this issue.

[acorbi]

@DragonVirus I think a potential solution would be to use jsonp https://learn.jquery.com/ajax/working-with-jsonp/