Created
July 16, 2020 14:14
-
-
Save timfoster/d4303cdc6221bd9523b5a71c665930b6 to your computer and use it in GitHub Desktop.
An Ansible plugin that builds an inventory from the output of 'getent hosts' on a remote machine
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/usr/bin/python | |
# -*- coding: utf-8 -*- | |
import socket | |
import subprocess | |
from ansible.plugins.inventory import BaseInventoryPlugin | |
DOCUMENTATION = r''' | |
name: remote_hosts | |
plugin_type: inventory | |
short_description: Returns an Ansible inventory from 'getent hosts' | |
description: | |
- Generate an inventory by connecting to a remote machine using ssh | |
- and running 'getent hosts'. | |
- The returned inventory is grouped into a 'xxx_hosts' group, where xxx | |
- is the remote_hostname. We assume that 'ssh' is on the path, and | |
- the system is able to connect using passwordless auth. | |
options: | |
plugin: | |
description: getent hosts inventory | |
required: true | |
remote_hostname: | |
description: The remote machine on which to run 'getent hosts'. | |
required: true | |
remote_user: | |
description: | |
- The user to connect to the remote machine as. | |
- If left empty, we connect as the current user. | |
required: false | |
author: Tim Foster @timfoster | |
''' | |
# | |
# For example: | |
# $ /bin/ls ~/.ansible/plugins/inventory/remote_hosts.py | |
# /Users/timf/.ansible/plugins/inventory/remote_hosts.py | |
# | |
# $ cat remote_inv.yml | |
# plugin: remote_hosts | |
# remote_hostname: puroto | |
# | |
# $ ansible-inventory -i remote_inv.yml --graph | |
# @all: | |
# |--@puroto_hosts: | |
# | |--LB2120.mhs | |
# | |--aeris | |
# | |--amiorangi | |
# | |--ampache | |
# | |--aratuku | |
# etc. | |
# | |
class InventoryModule(BaseInventoryPlugin): | |
NAME = 'remote_hosts' | |
def verify_file(self, path): | |
# This is really basic | |
if path.endswith(".yaml") or path.endswith(".yml"): | |
return True | |
return False | |
def parse(self, inventory, loader, path, cache=True): | |
super(InventoryModule, self).parse(inventory, loader, path, cache) | |
self.inventory = inventory | |
self.loader = loader | |
self.path = path | |
self.cache = cache | |
config = self._read_config_data(path) | |
remote_host = config.get("remote_hostname") | |
remote_user = config.get("remote_user") | |
if not remote_host: | |
raise Exception("Missing 'remote_hostname' configuration") | |
try: | |
socket.gethostbyname(remote_host) | |
except Exception as e: | |
raise Exception("Unable to reach %s: %s" % (s, e)) | |
group = "%s_hosts" % remote_host | |
self.inventory.add_group(group) | |
if remote_user: | |
ssh_cmd = "ssh -l %s %s getent hosts" % (remote_user, remote_host) | |
else: | |
ssh_cmd = "ssh %s getent hosts" % remote_host | |
completed = subprocess.run(ssh_cmd.split(), capture_output=True) | |
if completed.returncode != 0: | |
raise Exception("Unable to run command: %s" % ssh_cmd) | |
for line in completed.stdout.decode().split('\n'): | |
if not line: | |
continue | |
address, hosts = line.split(maxsplit=1) | |
for host in hosts.split(): | |
self.inventory.add_host(host.strip(), group) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment