custom netnir commands

Creating custom netnir commands is simple. The first thing that you do is create an installable python package with a class that follows the following format:

class Plugin:
    def __init__(self, args):
        self.args = args

    @staticmethod
    def parser(parser):
        parser.add_argument('--some-arg')

    def run(self):
        return self.args.some-arg

An example of this is:

$ cat setup.py
#!/usr/bin/env python3

import setuptools

setuptools.setup(
    name="example netnir plugin",
    packages=['netnir_plugin']
)

$ cat netnir_plugin/__init__.py
from netnir.helpers.common.args import filter_host

class ExamplePlugin:

    def __init__(self, args):
        self.args = args

    @staticmethod
    def parser(parser):
        parser.add_argument("--print", help="print something to the screen")
        filter_host(parser)

    def run(self):
        if self.args.host:
            return self.args.host
        elif self.args.print:
            return self.args.print
        else:
            return "nothing to print"

$ python
Python 3.8.1 (v3.8.1:1b293b6006, Dec 18 2019, 14:08:53)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import netnir_plugin

Once that is done, you can modify the netnir.yaml to add the plugin in the plugins section.

$ cat netnir.yaml
</omitted>
plugins:
</omitted>
  example:
    class: netnir_plugin.ExamplePlugin
    description: example netnir plugin

Then execute netnir.

$ netnir -h
usage: netnir [-h] [--version] {cp,fetch,inventory,setup,ssh,example} ...

optional arguments:
  -h, --help            show this help message and exit
  --version             display version

netnir commands:
  {cp,fetch,inventory,setup,ssh,example}
    cp                  config plan commands
    fetch               fetch commands
    inventory           inventory search command
    setup               netnir setup commands
    ssh                 command and config execution over SSH
    example             example netnir plugin

$ netnir example -h
usage: netnir example [-h] [--print PRINT] [--host HOST]

example netnir plugin

optional arguments:
  -h, --help     show this help message and exit
  --print PRINT  print something to the screen
  --host HOST    specify a specific host

$ netnir example --host router.dc1
'router.dc1'
$ netnir example --print 'some message'
'some message'