pseud 1.0.0a1

Bidirectionnal RPC Api on top of pyzmq

Pythonic bidirectional-rpc API built on top of ØMQ with pluggable encryption, authentication and heartbeating support.

Features

1. ØMQ transport layer.

2. All native python types supported (msgpack).

3. First citizen exceptions.

4. Bi-bidirectional (server can initiate calls to connected clients).

5. Encryption based on CURVE.

6. Pluggable Authentication.

7. Pluggable Heartbeating.

8. Pluggable Remote Call Routing.

9. Built-in proxy support. A server can delegate the work to another one.

10. SyncClient (using zmq.REQ) to use within non event based processes. (Heartbeating, Authentication and job execution are not supported with the SyncClient.)

Installation

$ pip install pseud

Execution

The Server

from pseud import Server


server = Server('service')
server.bind('tcp://127.0.0.1:5555')

@server.register_rpc
def hello(name):
    return 'Hello {0}'.format(name)

await server.start()  # this will block forever

The Client

from pseud import Client


client = Client('service', io_loop=loop)
client.connect('tcp://127.0.0.1:5555')

# Assume we are inside a coroutine
async with client:
    response = await client.hello('Charly')
    assert response == 'Hello Charly'

The SyncClient

# to use within a non-asynchronous process or in a command interpreter
from pseud import SyncClient


client = SyncClient()
client.connect('tcp://127.0.0.1:5555')

async with client:
    assert client.hello('Charly') == 'Hello Charly'

The Server send a command to the client

It is important to note that the server needs to know which peers are connected to it. This is why the security_plugin trusted_peer comes handy. It will register all peer id and be able to route messages to each of them.

from pseud import Server


server = Server('service', security_plugin='trusted_peer')
server.bind('tcp://127.0.0.1:5555')

@server.register_rpc
def hello(name):
    return 'Hello {0}'.format(name)

await server.start()  # this will block forever

The client needs to send its identity to the server. This is why plain security plugin is used. The server will not check the password, he will just take into consideration the user_id to perform the routing.

from pseud import Client


client = Client('service',
                security_plugin='plain',
                user_id='alice',
                password='')
client.connect('tcp://127.0.0.1:5555')

# Action that the client will perform when
# requested by the server.
@client.register_rpc(name='draw.me.a.sheep')
def sheep():
    return 'beeeh'

# The client needs to perform a first call
# to the server in order to register itself.
# on production this will be handle automatically
# by the heartbeat backend. The first heartbeat will
# trigger the authentication. Then until the client
# disconnect the server will not ask the client
# to reconnect.

# assume we are inside a coroutine
async with client:
     result = await client.hello('alice')
     assert result == 'Hello alice'

Back on server side, now the client as registered itself, we can send to it any commands the client is able to do.

# assume we are inside a coroutine
sheep = await server.send_to('alice').draw.me.a.sheep()
assert sheep == 'beeeh'

Documentation

Pseud on Readthedocs