sprockets.mixins.http

HTTP Client Mixin for Tornado RequestHandlers. Automatically retries on errors, sleep when rate limited, and handles content encoding and decoding using MsgPack and JSON.

Installation

sprockets.mixins.http is available on the Python Package Index and can be installed via pip:

pip install sprockets.mixins.http

If you would like to use tornado.curl_httpclient.CurlAsyncHTTPClient, you can install pycurl with:

pip install sprockets.mixins.http[curl]

Documentation

https://sprocketsmixinshttp.readthedocs.io

Requirements

• ietfparse >=1.5.1
• tornado >=5
• sprockets.mixins.mediatype[msgpack] >=3

Example

This examples demonstrates the most basic usage of sprockets.mixins.http

from tornado import ioloop, web
from sprockets.mixins import http


class RequestHandler(http.HTTPClientMixin, web.RequestHandler):

   async def get(self, *args, **kwargs):
       response = await self.http_fetch('https://api.github.com')
       if not response.ok:
           self.set_status(response.code)
       self.write(response.body)


if __name__ == "__main__":
   app = web.Application([(r'/', RequestHandler)])
   app.listen(8000)
   ioloop.IOLoop.current().start()

As with Tornado, to use the curl client which has numerous benefits:

from tornado import httpclient, ioloop, web
from sprockets.mixins import http

httpclient.AsyncHTTPClient.configure(
    'tornado.curl_httpclient.CurlAsyncHTTPClient')


class RequestHandler(http.HTTPClientMixin, web.RequestHandler):

   async def get(self, *args, **kwargs):
       response = await self.http_fetch('https://api.github.com')
       if not response.ok:
           self.set_status(response.code)
       self.write(response.body)


if __name__ == "__main__":
   app = web.Application([(r'/', RequestHandler)])
   app.listen(8000)
   ioloop.IOLoop.current().start()

Error Response Body

For errors, i.e. a response with HTTP status code in the 400 range...

The HTTPResponse object's body is reduced down to just the error message. That is this mixin's default behavior.

For a JSON response body with Problem Details (RFC 7807), you may want more than just the error message. To gain access to the complete, deserialized response body; a class that uses this mixin can set:

self.simplify_error_response = False

Environment Variables

HTTP_MAX_CLIENTS

An optional setting that specifies the maximum number of simultaneous asynchronous HTTP requests. If not specified, the default Tornado value of 10 will be used.

License

sprockets.mixins.http is released under the 3-Clause BSD license.