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Diffstat (limited to 'lib/ansible/plugins/inventory/constructed.py')
-rw-r--r-- | lib/ansible/plugins/inventory/constructed.py | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/lib/ansible/plugins/inventory/constructed.py b/lib/ansible/plugins/inventory/constructed.py new file mode 100644 index 0000000..dd630c6 --- /dev/null +++ b/lib/ansible/plugins/inventory/constructed.py @@ -0,0 +1,177 @@ +# Copyright (c) 2017 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: constructed + version_added: "2.4" + short_description: Uses Jinja2 to construct vars and groups based on existing inventory. + description: + - Uses a YAML configuration file with a valid YAML or C(.config) extension to define var expressions and group conditionals + - The Jinja2 conditionals that qualify a host for membership. + - The Jinja2 expressions are calculated and assigned to the variables + - Only variables already available from previous inventories or the fact cache can be used for templating. + - When I(strict) is False, failed expressions will be ignored (assumes vars were missing). + options: + plugin: + description: token that ensures this is a source file for the 'constructed' plugin. + required: True + choices: ['ansible.builtin.constructed', 'constructed'] + use_vars_plugins: + description: + - Normally, for performance reasons, vars plugins get executed after the inventory sources complete the base inventory, + this option allows for getting vars related to hosts/groups from those plugins. + - The host_group_vars (enabled by default) 'vars plugin' is the one responsible for reading host_vars/ and group_vars/ directories. + - This will execute all vars plugins, even those that are not supposed to execute at the 'inventory' stage. + See vars plugins docs for details on 'stage'. + required: false + default: false + type: boolean + version_added: '2.11' + extends_documentation_fragment: + - constructed +''' + +EXAMPLES = r''' + # inventory.config file in YAML format + plugin: ansible.builtin.constructed + strict: False + compose: + var_sum: var1 + var2 + + # this variable will only be set if I have a persistent fact cache enabled (and have non expired facts) + # `strict: False` will skip this instead of producing an error if it is missing facts. + server_type: "ansible_hostname | regex_replace ('(.{6})(.{2}).*', '\\2')" + groups: + # simple name matching + webservers: inventory_hostname.startswith('web') + + # using ec2 'tags' (assumes aws inventory) + development: "'devel' in (ec2_tags|list)" + + # using other host properties populated in inventory + private_only: not (public_dns_name is defined or ip_address is defined) + + # complex group membership + multi_group: (group_names | intersect(['alpha', 'beta', 'omega'])) | length >= 2 + + keyed_groups: + # this creates a group per distro (distro_CentOS, distro_Debian) and assigns the hosts that have matching values to it, + # using the default separator "_" + - prefix: distro + key: ansible_distribution + + # the following examples assume the first inventory is from the `aws_ec2` plugin + # this creates a group per ec2 architecture and assign hosts to the matching ones (arch_x86_64, arch_sparc, etc) + - prefix: arch + key: architecture + + # this creates a group per ec2 region like "us_west_1" + - prefix: "" + separator: "" + key: placement.region + + # this creates a common parent group for all ec2 availability zones + - key: placement.availability_zone + parent_group: all_ec2_zones +''' + +import os + +from ansible import constants as C +from ansible.errors import AnsibleParserError, AnsibleOptionsError +from ansible.inventory.helpers import get_group_vars +from ansible.plugins.inventory import BaseInventoryPlugin, Constructable +from ansible.module_utils._text import to_native +from ansible.utils.vars import combine_vars +from ansible.vars.fact_cache import FactCache +from ansible.vars.plugins import get_vars_from_inventory_sources + + +class InventoryModule(BaseInventoryPlugin, Constructable): + """ constructs groups and vars using Jinja2 template expressions """ + + NAME = 'constructed' + + def __init__(self): + + super(InventoryModule, self).__init__() + + self._cache = FactCache() + + def verify_file(self, path): + + valid = False + if super(InventoryModule, self).verify_file(path): + file_name, ext = os.path.splitext(path) + + if not ext or ext in ['.config'] + C.YAML_FILENAME_EXTENSIONS: + valid = True + + return valid + + def get_all_host_vars(self, host, loader, sources): + ''' requires host object ''' + return combine_vars(self.host_groupvars(host, loader, sources), self.host_vars(host, loader, sources)) + + def host_groupvars(self, host, loader, sources): + ''' requires host object ''' + gvars = get_group_vars(host.get_groups()) + + if self.get_option('use_vars_plugins'): + gvars = combine_vars(gvars, get_vars_from_inventory_sources(loader, sources, host.get_groups(), 'all')) + + return gvars + + def host_vars(self, host, loader, sources): + ''' requires host object ''' + hvars = host.get_vars() + + if self.get_option('use_vars_plugins'): + hvars = combine_vars(hvars, get_vars_from_inventory_sources(loader, sources, [host], 'all')) + + return hvars + + def parse(self, inventory, loader, path, cache=False): + ''' parses the inventory file ''' + + super(InventoryModule, self).parse(inventory, loader, path, cache=cache) + + self._read_config_data(path) + + sources = [] + try: + sources = inventory.processed_sources + except AttributeError: + if self.get_option('use_vars_plugins'): + raise AnsibleOptionsError("The option use_vars_plugins requires ansible >= 2.11.") + + strict = self.get_option('strict') + fact_cache = FactCache() + try: + # Go over hosts (less var copies) + for host in inventory.hosts: + + # get available variables to templar + hostvars = self.get_all_host_vars(inventory.hosts[host], loader, sources) + if host in fact_cache: # adds facts if cache is active + hostvars = combine_vars(hostvars, fact_cache[host]) + + # create composite vars + self._set_composite_vars(self.get_option('compose'), hostvars, host, strict=strict) + + # refetch host vars in case new ones have been created above + hostvars = self.get_all_host_vars(inventory.hosts[host], loader, sources) + if host in self._cache: # adds facts if cache is active + hostvars = combine_vars(hostvars, self._cache[host]) + + # constructed groups based on conditionals + self._add_host_to_composed_groups(self.get_option('groups'), hostvars, host, strict=strict, fetch_hostvars=False) + + # constructed groups based variable values + self._add_host_to_keyed_groups(self.get_option('keyed_groups'), hostvars, host, strict=strict, fetch_hostvars=False) + + except Exception as e: + raise AnsibleParserError("failed to parse %s: %s " % (to_native(path), to_native(e)), orig_exc=e) |