aio-alf

aiohttp OAuth 2 Client

aio-alf is a OAuth 2 Client base on the aiohttp's AsyncHTTPClient

Features

• Automatic token retrieving and renewing
• Token expiration control
• Automatic retry on status 401 (UNAUTHORIZED)

Usage

Initialize the client and use it as a AsyncHTTPClient object.

from aioalf.client import Client
from aioalf.httpclient import HTTPRequest

client = Client(
    token_endpoint='http://example.com/token',
    client_id='client-id',
    client_secret='secret')

resource_uri = 'http://example.com/resource'

response = await client.request(
    'POST',
    resource_uri,
    data='{"name": "alf"}',
    headers={'Content-Type': 'application/json'}
)

Alternatively one can pass directly a string to the fetch client

# ...
response = await client.request(
    'POST',
    'http://example.com/resource',
    data='{"name": "alf"}',
    headers={'Content-Type': 'application/json'}
)

Implicit Flow

Support for OAuth2 implict flow to enable it, call use_implicit_flow with a TokenStorage object and a port range, it defaults to the range (32000, 32009).

Example:

await use_implicit_flow(TokenStorage(), (30000, 30009))

async with Client(token_endpoint='https://token.endpoint',
                  client_id='glBQ3nYU/8/kaVi/bIgXGA==',
                  client_secret='') as client:
    response = await client.request('GET', 'http://example.com/resource')
    text = await response.text()
    print(response.status)

The library has a really simple in memory token storage, you should subclass and overwrite its methods if you need to persist the token for a longer period.

How it works?

Before any request the client tries to retrieve a token on the endpoint, expecting a JSON response with the access_token and expires_in keys.

The client keeps the token until it is expired, according to the expires_in value.

After getting the token, the request is issued with a Bearer authorization header:

GET /resource/1 HTTP/1.1
Host: example.com
Authorization: Bearer token

If the request fails with a 401 (UNAUTHORIZED) status, a new token is retrieved from the endpoint and the request is retried. This happens only once, if it fails again the error response is returned.

Troubleshooting

In case of an error retrieving a token, the error response will be returned, the real request won't happen.

Related projects

This project tries to be an adaptation to aiohttp of alf