zhenghao1 / wsgicors

WSGI for Cross Origin Resource Sharing (CORS)

wsgicors

This is a WSGI middleware that answers CORS preflight requests and adds the needed header to the response. For CORS see: http://www.w3.org/TR/cors/

Usage

Either plug it in programmatically as in this pyramid example:

def app(global_config, **settings):
    """ This function returns a WSGI application.
    
    It is usually called by the PasteDeploy framework during 
    ``paster serve``.
    """

    def get_root(request):
        return {}

    config = Configurator(root_factory=get_root, settings=settings)
    config.begin()
    # whatever it takes to config your app goes here
    config.end()

    from wsgicors import CORS
    return CORS(config.make_wsgi_app(), headers="*", methods="*", maxage="180", origin="*")

or plug it into your wsgi pipeline via paste ini to let it serve by waitress for instance:

[app:myapp]
use = egg:mysuperapp#app

###
# wsgi server configuration
###

[server:main]
use = egg:waitress#main
host = 0.0.0.0
port = 6543

[pipeline:main]
pipeline =
    cors
    myapp

[filter:cors]
use = egg:wsgicors#middleware
policy=free
free_origin=copy
free_headers=*
free_methods=*
free_maxage=180

Keywords are:

• origin
• headers
• methods
• credentials
• maxage

for origin:

• use copy which will copy whatever origin the request comes from
• any other literal will be be copied verbatim (like * for instance to allow every source)

for headers:

• use * which will allow whatever header is asked for
• any other literal will be be copied verbatim (like * for instance to allow every source)

for methods:

• use * which will allow whatever method is asked for
• any other literal will be be copied verbatim (like POST, PATCH, PUT, DELETE for instance)

for credentials:

• use true
• anything else will be ignored (that is no response header for Access-Control-Allow-Credentials is sent)

for maxage:

• give the number of seconds the answer can be used by a client, anything nonempty will be copied verbatim

As can be seen in the example above, a policy needs to be created with the policy keyword. The options need then be prefixed with the policy name and a _.