Okonf

Asynchronous configuration management system based on Python Asyncio.

Okonf manages the state and configuration of POSIX compatible systems. You can use it to configure your personal computers, servers, routers, ...

Okonf promotes a declarative syntax, where the goal is to ensure a given state of the target host instead of running commands on it.

Okonf emphasizes on being easy to use as a library in your own applications, and easy to extend with reusable components.

Okonf also focuses on excellent performance by running asynchronously.

Inspired by: pyinfra, Ansible, SaltStack.

Status

Okonf is still in early development, and it's API is subject to changes.

Suggestions and contributions are welcome.

Usage as a library

from okonf.connectors import LocalHost
from okonf.facts.files import FileContent
from okonf.utils import run_coroutine

host = LocalHost()

run_coroutine(
    FileContent('/tmp/some_file', b'Some Content').apply(host),
)

More advanced usage:

import asyncio
from okonf.connectors.ssh import SSHHost
from okonf import Collection
from okonf.facts.files import FileContent
from okonf.facts.git import GitClone

host = SSHHost(host='127.0.0.1', username='myuser')

facts = Collection([
    FileContent('/tmp/some_file', b'Some Content'),
    GitClone('git@github.com:okeso/Okonf.git', '/opt/Okonf'),
])

asyncio.run(Collection.apply(host))

Usage as a tool

Declare your infrastructure in a Python file (here named infra.py) with your two dictionnaries named hosts and configs. For example, we like to have vim, tree and htop installed on our systems:

from okonf import Sequence
from okonf.connectors import LocalHost
from okonf.facts.files import FileContent

hosts = {
    'laptop': LocalHost(),
}

configs = {
    'laptop': Sequence((
        FileContent(
            remote_path=f'/tmp/hello-{i}.txt',
            content=f"Hello number {i}.".encode(),
        ) for i in range(3)),
    ),
}

If you installed Okonf via pip, you should then be able to check the current state with:

okonf check infra.py laptop

And to apply your configuration using:

okonf apply infra.py laptop

Now that you got the basics, you can replace the connector with an SSHHost, and look at other facts you want to use.

Collections

Okonf provides two types of collections to group tasks into new higher level tasks: Collection and Sequence.

A Collection of facts will apply each of them in parallel, asynchronously.

A Sequence of facts will apply each fact after the previous one, in a sequential manner.

In the example below, the two facts help prividing a common functionnality, but they do not depend on each other and can be applied in parallel:

from okonf import Collection
from okonf.facts.apt import AptPresent
from okonf.facts.files import FileCopy


vim_configured = Collection([
    AptPresent('vim'),
    FileCopy('~/.vimrc', 'vimrc'),
])

In this other example however, each fact depends on the previous one, so they are applied sequentially:

from okonf import Sequence
from okonf.facts.apt import AptPresent
from okonf.facts.files import DirectoryPresent
from okonf.facts.python import Virtualenv, PipInstalled


ipython_virtualenv = Sequence([
    AptPresent('virtualenv'),
    DirectoryPresent('~/.virtualenvs/'),
    Virtualenv('~/.virtualenvs/venv-ipython'),
    PipInstalled(['itpython'], '~/.virtualenvs/venv-ipython'),
])

Creating facts

The example below shows the definition of the fact to ensure that a file is present on disk. The enquire method returns whether the file is present, and the enforce method is called if the file is absent to create it by running shell commands on the host.

from okonf.facts.abstract import Fact


class FilePresent(Fact):
    """Ensure that a file is present"""

    def __init__(self, remote_path: str) -> None:
        self.remote_path = remote_path

    async def enquire(self, host):
        command = "ls -d {}".format(self.remote_path)
        return await host.check_output(command, check=False) != ''

    async def enforce(self, host):
        await host.check_output("touch {}".format(self.remote_path))
        return True

License

Okonf is licensed under the Apache License 2.0.