Added Ansible Tower inventory plugin. (#41816)

Signed-off-by: Yunfan Zhang <yz322@duke.edu>

lib/ansible/plugins/inventory/tower.py

@@ -0,0 +1,187 @@
+# Copyright (c) 2018 Ansible Project
+# 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: tower
+    plugin_type: inventory
+    authors:
+      - Matthew Jones (@matburt)
+      - Yunfan Zhang (@YunfanZhang42)
+    short_description: Ansible dynamic inventory plugin for Ansible Tower.
+    version_added: "2.7"
+    description:
+        - Reads inventories from Ansible Tower.
+        - Supports reading configuration from both YAML config file and environment variables.
+        - If reading from the YAML file, the file name must end with tower_inventory.(yml|yaml),
+          the path in the command would be /path/to/tower_inventory.(yml|yaml). If some arguments in the config file
+          are missing, this plugin will try to fill in missing arguments by reading from environment variables.
+        - If reading configurations from environment variables, the path in the command must be @tower_inventory.
+    options:
+        plugin:
+            description: the name of this plugin, it should always be set to 'tower'
+                for this plugin to recognize it as it's own.
+            env:
+                - name: ANSIBLE_INVENTORY_ENABLED
+            required: True
+            choices: ['tower']
+        host:
+            description: The network address of your Ansible Tower host.
+            type: string
+            env:
+                - name: TOWER_HOST
+            required: True
+        username:
+            description: The user that you plan to use to access inventories on Ansible Tower.
+            type: string
+            env:
+                - name: TOWER_USERNAME
+            required: True
+        password:
+            description: The password for your Ansible Tower user.
+            type: string
+            env:
+                - name: TOWER_PASSWORD
+            required: True
+        inventory_id:
+            description: The ID of the Ansible Tower inventory that you wish to import.
+            type: string
+            env:
+                - name: TOWER_INVENTORY
+            required: True
+        verify_ssl:
+            description: Specify whether Ansible should verify the SSL certificate of Ansible Tower host.
+            type: bool
+            default: True
+            env:
+                - name: TOWER_VERIFY_SSL
+            required: False
+'''
+
+EXAMPLES = '''
+# Before you execute the following commands, you should make sure this file is in your plugin path,
+# and you enabled this plugin.
+
+# Example for using tower_inventory.yml file
+
+plugin: tower
+host: your_ansible_tower_server_network_address
+username: your_ansible_tower_username
+password: your_ansible_tower_password
+inventory_id: the_ID_of_targeted_ansible_tower_inventory
+# Then you can run the following command.
+# If some of the arguments are missing, Ansible will attempt to read them from environment variables.
+# ansible-inventory -i /path/to/tower_inventory.yml --list
+
+# Example for reading from environment variables:
+
+# Set environment variables:
+# export TOWER_HOST=YOUR_TOWER_HOST_ADDRESS
+# export TOWER_USERNAME=YOUR_TOWER_USERNAME
+# export TOWER_PASSWORD=YOUR_TOWER_PASSWORD
+# export TOWER_INVENTORY=THE_ID_OF_TARGETED_INVENTORY
+# Read the inventory specified in TOWER_INVENTORY from Ansible Tower, and list them.
+# The inventory path must always be @tower_inventory if you are reading all settings from environment variables.
+# ansible-inventory -i @tower_inventory --list
+'''
+
+import re
+import os
+import json
+from ansible.module_utils import six
+from ansible.module_utils.urls import Request, urllib_error, ConnectionError, socket, httplib
+from ansible.module_utils._text import to_native
+from ansible.errors import AnsibleParserError
+from ansible.plugins.inventory import BaseInventoryPlugin
+
+# Python 2/3 Compatibility
+try:
+    from urlparse import urljoin
+except ImportError:
+    from urllib.parse import urljoin
+
+
+class InventoryModule(BaseInventoryPlugin):
+    NAME = 'tower'
+    # Stays backward compatible with tower inventory script.
+    # If the user supplies '@tower_inventory' as path, the plugin will read from environment variables.
+    no_config_file_supplied = False
+
+    def read_tower_inventory(self, tower_host, tower_user, tower_pass, inventory, verify_ssl=True):
+        if not re.match('(?:http|https)://', tower_host):
+            tower_host = 'https://{tower_host}'.format(tower_host=tower_host)
+        inventory_id = inventory.replace('/', '')
+        inventory_url = '/api/v2/inventories/{inv_id}/script/?hostvars=1&towervars=1&all=1'.format(inv_id=inventory_id)
+        inventory_url = urljoin(tower_host, inventory_url)
+
+        request_handler = Request(url_username=tower_user,
+                                  url_password=tower_pass,
+                                  force_basic_auth=True,
+                                  validate_certs=verify_ssl)
+
+        try:
+            response = request_handler.get(inventory_url)
+        except (ConnectionError, urllib_error.URLError, socket.error, httplib.HTTPException) as e:
+            error_msg = 'Connection to remote host failed: {err}'.format(err=e)
+            # If Tower gives a readable error message, display that message to the user.
+            if callable(getattr(e, 'read', None)):
+                error_msg += ' with message: {err_msg}'.format(err_msg=e.read())
+            raise AnsibleParserError(to_native(error_msg))
+
+        # Attempt to parse JSON.
+        try:
+            return json.loads(response.read())
+        except (ValueError, TypeError) as e:
+            # If the JSON parse fails, print the ValueError
+            raise AnsibleParserError(to_native('Failed to parse json from host: {err}'.format(err=e)))
+
+    def verify_file(self, path):
+        if path.endswith('@tower_inventory'):
+            self.no_config_file_supplied = True
+            return True
+        elif super(InventoryModule, self).verify_file(path):
+            return path.endswith('tower_inventory.yml') or path.endswith('tower_inventory.yaml')
+        else:
+            return False
+
+    def parse(self, inventory, loader, path, cache=True):
+        super(InventoryModule, self).parse(inventory, loader, path)
+        if not self.no_config_file_supplied and os.path.isfile(path):
+            self._read_config_data(path)
+        # Read inventory from tower server.
+        # Note the environment variables will be handled automatically by InventoryManager.
+        inventory = self.read_tower_inventory(self.get_option('host'),
+                                              self.get_option('username'),
+                                              self.get_option('password'),
+                                              self.get_option('inventory_id'),
+                                              verify_ssl=self.get_option('verify_ssl'))
+        # To start with, create all the groups.
+        for group_name in inventory:
+            if group_name != '_meta':
+                self.inventory.add_group(group_name)
+
+        # Then, create all hosts and add the host vars.
+        all_hosts = inventory['_meta']['hostvars']
+        for host_name, host_vars in six.iteritems(all_hosts):
+            self.inventory.add_host(host_name)
+            for var_name, var_value in six.iteritems(host_vars):
+                self.inventory.set_variable(host_name, var_name, var_value)
+
+        # Lastly, create to group-host and group-group relationships, and set group vars.
+        for group_name, group_content in six.iteritems(inventory):
+            if group_name != 'all' and group_name != '_meta':
+                # First add hosts to groups
+                for host_name in group_content.get('hosts', []):
+                    self.inventory.add_host(host_name, group_name)
+                # Then add the parent-children group relationships.
+                for child_group_name in group_content.get('children', []):
+                    self.inventory.add_child(group_name, child_group_name)
+            # Set the group vars. Note we should set group var for 'all', but not '_meta'.
+            if group_name != '_meta':
+                for var_name, var_value in six.iteritems(group_content.get('vars', {})):
+                    self.inventory.set_variable(group_name, var_name, var_value)
+        # Clean up the inventory.
+        self.inventory.reconcile_inventory()