oslo.middleware/doc/source/reference/cors.rst

CORS Middleware

This middleware provides a comprehensive, configurable implementation of the CORS (Cross Origin Resource Sharing) specification as oslo-supported python wsgi middleware.

Note

While this middleware supports the use of the * wildcard origin in the specification, this feature is not recommended for security reasons. It is provided to simplify basic use of CORS, practically meaning "I don't care how this is used." In an intranet setting, this could lead to leakage of data beyond the intranet and therefore should be avoided.

Quickstart

First, include the middleware in your application:

from oslo_middleware import cors

app = cors.CORS(your_wsgi_application)

Secondly, add as many allowed origins as you would like:

app.add_origin(allowed_origin='https://website.example.com:443',
               allow_credentials=True,
               max_age=3600,
               allow_methods=['GET','PUT','POST','DELETE'],
               allow_headers=['X-Custom-Header'],
               expose_headers=['X-Custom-Header'])

# ... add more origins here.

Configuration for oslo_config

A factory method has been provided to simplify configuration of your CORS domain, using oslo_config:

from oslo_middleware import cors
from oslo_config import cfg

app = cors.CORS(your_wsgi_application, cfg.CONF)

In your application's config file, then include a configuration block something like this:

[cors]
allowed_origin=https://website.example.com:443,https://website2.example.com:443
max_age=3600
allow_methods=GET,POST,PUT,DELETE
allow_headers=X-Custom-Header
expose_headers=X-Custom-Header

Configuration for pastedeploy

If your application is using pastedeploy, the following configuration block will add CORS support.:

[filter:cors]
use = egg:oslo.middleware#cors
allowed_origin=https://website.example.com:443,https://website2.example.com:443
max_age=3600
allow_methods=GET,POST,PUT,DELETE
allow_headers=X-Custom-Header
expose_headers=X-Custom-Header

If your application is using pastedeploy, but would also like to use the existing configuration from oslo_config in order to simplify the points of configuration, this may be done as follows.:

[filter:cors]
use = egg:oslo.middleware#cors
oslo_config_project = oslo_project_name

# Optional field, in case the program name is different from the project:
oslo_config_program = oslo_project_name-api

Configuration Options

oslo.middleware.cors

Module Documentation

oslo_middleware.cors