constructed – Uses Jinja2 to construct vars and groups based on existing inventory¶
New in version 2.4.
Synopsis¶
- Uses a YAML configuration file with a valid YAML or .configextension 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 strict is False, failed expressions will be ignored (assumes vars were missing).
Parameters¶
Examples¶
# inventory.config file in YAML format
plugin: 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 contrib/inventory/ec2.py
    # this creates a group per ec2 architecture and assign hosts to the matching ones (arch_x86_64, arch_sparc, etc)
    - prefix: arch
      key: ec2_architecture
    # this creates a group per ec2 region like "us_west_1"
    - prefix: ""
      separator: ""
      key: ec2_region
    # this creates a common parent group for all ec2 availability zones
    - key: ec2_placement
      parent_group: all_ec2_zones
Status¶
- This inventory is not guaranteed to have a backwards compatible interface. [preview]
- This inventory is maintained by the Ansible Community. [community]
Authors¶
- UNKNOWN
Hint
If you notice any issues in this documentation, you can edit this document to improve it.
Hint
Configuration entries for each entry type have a low to high priority order. For example, a variable that is lower in the list will override a variable that is higher up.
