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community.general/plugins/inventory/docker_machine.py
Ansible Core Team aebc1b03fd Initial commit
2020-03-09 09:11:07 +00:00

256 lines
11 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (c) 2019, Ximon Eighteen <ximon.eighteen@gmail.com>
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
DOCUMENTATION = '''
name: docker_machine
plugin_type: inventory
author: Ximon Eighteen (@ximon18)
short_description: Docker Machine inventory source
requirements:
- L(Docker Machine,https://docs.docker.com/machine/)
extends_documentation_fragment:
- constructed
description:
- Get inventory hosts from Docker Machine.
- Uses a YAML configuration file that ends with docker_machine.(yml|yaml).
- The plugin sets standard host variables C(ansible_host), C(ansible_port), C(ansible_user) and C(ansible_ssh_private_key).
- The plugin stores the Docker Machine 'env' output variables in I(dm_) prefixed host variables.
options:
plugin:
description: token that ensures this is a source file for the C(docker_machine) plugin.
required: yes
choices: ['docker_machine']
daemon_env:
description:
- Whether docker daemon connection environment variables should be fetched, and how to behave if they cannot be fetched.
- With C(require) and C(require-silently), fetch them and skip any host for which they cannot be fetched.
A warning will be issued for any skipped host if the choice is C(require).
- With C(optional) and C(optional-silently), fetch them and not skip hosts for which they cannot be fetched.
A warning will be issued for hosts where they cannot be fetched if the choice is C(optional).
- With C(skip), do not attempt to fetch the docker daemon connection environment variables.
- If fetched successfully, the variables will be prefixed with I(dm_) and stored as host variables.
type: str
choices:
- require
- require-silently
- optional
- optional-silently
- skip
default: require
running_required:
description: when true, hosts which Docker Machine indicates are in a state other than C(running) will be skipped.
type: bool
default: yes
verbose_output:
description: when true, include all available nodes metadata (e.g. Image, Region, Size) as a JSON object named C(docker_machine_node_attributes).
type: bool
default: yes
'''
EXAMPLES = '''
# Minimal example
plugin: docker_machine
# Example using constructed features to create a group per Docker Machine driver
# (https://docs.docker.com/machine/drivers/), e.g.:
# $ docker-machine create --driver digitalocean ... mymachine
# $ ansible-inventory -i ./path/to/docker-machine.yml --host=mymachine
# {
# ...
# "digitalocean": {
# "hosts": [
# "mymachine"
# ]
# ...
# }
strict: no
keyed_groups:
- separator: ''
key: docker_machine_node_attributes.DriverName
# Example grouping hosts by Digital Machine tag
strict: no
keyed_groups:
- prefix: tag
key: 'dm_tags'
# Example using compose to override the default SSH behaviour of asking the user to accept the remote host key
compose:
ansible_ssh_common_args: '"-o StrictHostKeyChecking=accept-new"'
'''
from ansible.errors import AnsibleError
from ansible.module_utils._text import to_native
from ansible.module_utils._text import to_text
from ansible.module_utils.common.process import get_bin_path
from ansible.plugins.inventory import BaseInventoryPlugin, Constructable, Cacheable
from ansible.utils.display import Display
import json
import re
import subprocess
display = Display()
class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
''' Host inventory parser for ansible using Docker machine as source. '''
NAME = 'community.general.docker_machine'
DOCKER_MACHINE_PATH = None
def _run_command(self, args):
if not self.DOCKER_MACHINE_PATH:
try:
self.DOCKER_MACHINE_PATH = get_bin_path('docker-machine')
except ValueError as e:
raise AnsibleError(to_native(e))
command = [self.DOCKER_MACHINE_PATH]
command.extend(args)
display.debug('Executing command {0}'.format(command))
try:
result = subprocess.check_output(command)
except subprocess.CalledProcessError as e:
display.warning('Exception {0} caught while executing command {1}, this was the original exception: {2}'.format(type(e).__name__, command, e))
raise e
return to_text(result).strip()
def _get_docker_daemon_variables(self, machine_name):
'''
Capture settings from Docker Machine that would be needed to connect to the remote Docker daemon installed on
the Docker Machine remote host. Note: passing '--shell=sh' is a workaround for 'Error: Unknown shell'.
'''
try:
env_lines = self._run_command(['env', '--shell=sh', machine_name]).splitlines()
except subprocess.CalledProcessError:
# This can happen when the machine is created but provisioning is incomplete
return []
# example output of docker-machine env --shell=sh:
# export DOCKER_TLS_VERIFY="1"
# export DOCKER_HOST="tcp://134.209.204.160:2376"
# export DOCKER_CERT_PATH="/root/.docker/machine/machines/routinator"
# export DOCKER_MACHINE_NAME="routinator"
# # Run this command to configure your shell:
# # eval $(docker-machine env --shell=bash routinator)
# capture any of the DOCKER_xxx variables that were output and create Ansible host vars
# with the same name and value but with a dm_ name prefix.
vars = []
for line in env_lines:
match = re.search('(DOCKER_[^=]+)="([^"]+)"', line)
if match:
env_var_name = match.group(1)
env_var_value = match.group(2)
vars.append((env_var_name, env_var_value))
return vars
def _get_machine_names(self):
# Filter out machines that are not in the Running state as we probably can't do anything useful actions
# with them.
ls_command = ['ls', '-q']
if self.get_option('running_required'):
ls_command.extend(['--filter', 'state=Running'])
try:
ls_lines = self._run_command(ls_command)
except subprocess.CalledProcessError:
return []
return ls_lines.splitlines()
def _inspect_docker_machine_host(self, node):
try:
inspect_lines = self._run_command(['inspect', self.node])
except subprocess.CalledProcessError:
return None
return json.loads(inspect_lines)
def _should_skip_host(self, machine_name, env_var_tuples, daemon_env):
if not env_var_tuples:
warning_prefix = 'Unable to fetch Docker daemon env vars from Docker Machine for host {0}'.format(machine_name)
if daemon_env in ('require', 'require-silently'):
if daemon_env == 'require':
display.warning('{0}: host will be skipped'.format(warning_prefix))
return True
else: # 'optional', 'optional-silently'
if daemon_env == 'optional':
display.warning('{0}: host will lack dm_DOCKER_xxx variables'.format(warning_prefix))
return False
def _populate(self):
daemon_env = self.get_option('daemon_env')
try:
for self.node in self._get_machine_names():
self.node_attrs = self._inspect_docker_machine_host(self.node)
if not self.node_attrs:
continue
machine_name = self.node_attrs['Driver']['MachineName']
# query `docker-machine env` to obtain remote Docker daemon connection settings in the form of commands
# that could be used to set environment variables to influence a local Docker client:
if daemon_env == 'skip':
env_var_tuples = []
else:
env_var_tuples = self._get_docker_daemon_variables(machine_name)
if self._should_skip_host(machine_name, env_var_tuples, daemon_env):
continue
# add an entry in the inventory for this host
self.inventory.add_host(machine_name)
# set standard Ansible remote host connection settings to details captured from `docker-machine`
# see: https://docs.ansible.com/ansible/latest/user_guide/intro_inventory.html
self.inventory.set_variable(machine_name, 'ansible_host', self.node_attrs['Driver']['IPAddress'])
self.inventory.set_variable(machine_name, 'ansible_port', self.node_attrs['Driver']['SSHPort'])
self.inventory.set_variable(machine_name, 'ansible_user', self.node_attrs['Driver']['SSHUser'])
self.inventory.set_variable(machine_name, 'ansible_ssh_private_key_file', self.node_attrs['Driver']['SSHKeyPath'])
# set variables based on Docker Machine tags
tags = self.node_attrs['Driver'].get('Tags') or ''
self.inventory.set_variable(machine_name, 'dm_tags', tags)
# set variables based on Docker Machine env variables
for kv in env_var_tuples:
self.inventory.set_variable(machine_name, 'dm_{0}'.format(kv[0]), kv[1])
if self.get_option('verbose_output'):
self.inventory.set_variable(machine_name, 'docker_machine_node_attributes', self.node_attrs)
# Use constructed if applicable
strict = self.get_option('strict')
# Composed variables
self._set_composite_vars(self.get_option('compose'), self.node_attrs, machine_name, strict=strict)
# Complex groups based on jinja2 conditionals, hosts that meet the conditional are added to group
self._add_host_to_composed_groups(self.get_option('groups'), self.node_attrs, machine_name, strict=strict)
# Create groups based on variable values and add the corresponding hosts to it
self._add_host_to_keyed_groups(self.get_option('keyed_groups'), self.node_attrs, machine_name, strict=strict)
except Exception as e:
raise AnsibleError('Unable to fetch hosts from Docker Machine, this was the original exception: %s' %
to_native(e), orig_exc=e)
def verify_file(self, path):
"""Return the possibility of a file being consumable by this plugin."""
return (
super(InventoryModule, self).verify_file(path) and
path.endswith((self.NAME + '.yaml', self.NAME + '.yml')))
def parse(self, inventory, loader, path, cache=True):
super(InventoryModule, self).parse(inventory, loader, path, cache)
self._read_config_data(path)
self._populate()