Ansible/Splitting Hosts File

Main article: Ansible/Hosts

Strategy: create separate variable file for each host and each group

These variable files should be in YAML format

If your playbooks are in playbooks/, and your hosts file is in playbooks/hosts, then you would organize the directory as follows:

• put variables for the host california.example.com into the file playbooks/host_vars/california.example.com
• put variables for the production group in the file playbooks/group_vars/production

Examples

Example of flat group variables file

Here is an example of how group variables could be used for a production environment, and all defined in a single file:

group_vars/production:

db_primary_host: rhodeisland.example.com
db_primary_port=5432
db_replica_host: virginia.example.com
db_name: widget_production
db_user: widgetuser
db_password: pFmMxcyD;Fc6)6
rabbitmq_host:pennsylvania.example.com
rabbitmq_port=5672

Variables are accessed using the Jinja template variable notation:

{{ db_primary_host }}

Example of YAML group variables file

The group variables file can also be represented with YAML:

group_vars/production:

db:
    user: widgetuser
    password: pFmMxcyD;Fc6)6
    name: widget_production
    primary:
        host: rhodeisland.example.com
        port: 5432
    replica:
        host: virginia.example.com
        port: 5432

rabbitmq:
    host: pennsylvania.example.com
    port: 5672

Variables are accessed using nested variable notation:

{{ db.primary.host }}

Further breakdown

You can break it down even further by making production a directory, and then further group variables into separate files (e.g., one per service).

Rule of thumb: keep it simple. Only use this approach if you really need to.