chopsticks 0.3

Chopsticks is an orchestration library: it lets you manage and configure remote hosts over SSH.

Chopsticks is an orchestration library: it lets you manage and configure remote hosts over SSH.

Naturally this is agentless and nothing needs to be installed on the remote host.

It’s perhaps best compared to Ansible or Fabric, but has some clever transport magic which means it’s very easy to develop with: you just write Python functions that can be called from the orchestration host. No invoking bash commands (eg. Fabric) or writing self-contained scripts with constrained input and output formats (eg. Ansible).

One might also draw a comparison with Python’s built-in multiprocessing library, but instead of calling code in subprocesses on the same host, the code may be run on remote hosts.

Example

With chopsticks you can simply import functions and hand them to the remote host to be executed.

First stand up an SSH Tunnel:

from chopsticks.tunnel import Tunnel
tun = Tunnel('troy.example.com')

Then you can pass a function, to be called on the remote host:

import time
print('Time on %s:' % tun.host, tun.call(time.time))

The intention would be to build in some useful facts and config management capabilities; currently only chopsticks.facts.ip is a thing:

from chopsticks.facts import ip

print('%s ip:' % tun.host, tun.call(ip))

Tunnel provides support for executing on a single host; there is also a Group that can execute a callable on a number of hosts in parallel:

from chopsticks.group import Group

group = Group([
    'web1.example.com',
    'web2.example.com',
    'web3.example.com',
])
for host, addr in group.call(ip).iteritems():
    print('%s ip:' % host, addr)

Installation

Chopsticks can be used directly from a clone of the repo; or installed with pip:

$ pip install chopsticks

API

See full documentation on Read The Docs.

How it works

The SSH tunnel invokes the python binary on the remote host, and feeds it a bootstrap script via stdin.

Once bootstrapped, the remote “agent” sets up bi-directional communication over the stdin/stdout of the tunnel (stderr is currently not consumed and can therefore be used to feed debugging information back to the controlling terminal). This communication is used (currently) for two purposes:

• An RPC system to invoke arbitrary callables within the remote agent and pass the returned values back to the controller.

• A PEP-302 import hook system, allowing the remote agent to import pure-Python code from the controller (NB. the controller can only serve Python modules that live within the filesystem - import hooks such as zipimport/compressed eggs are not currently supported).

stdin/stdout on the agent are redirected to /dev/null.

License

Apache License 2.0