Ansible: trying to put conditionals on a vars file

Question

I'm working on a project that will use a number of devices that will need to be configured with the same plays, but separate variables. I have a vars file which includes a number of libraries, one for each device. The name of the library matches the name of the device, for example:

(Device1)

- {xxx: "AAA", yyy: "BBB", zzz: "CCC"}
- {xxx: "AAA", yyy: "BBB", zzz: "CCC"}

(Device2)

- {xxx: "AAA", yyy: "BBB", zzz: "CCC"}
- {xxx: "AAA", yyy: "BBB", zzz: "CCC"}

The play itself is supposed to figure out which library matches the device, use that library's variables and none of the other ones. My current attempt is done like this:

- name: do this
  command: "do some of item.xxx with some item.zzz
- include_vars: device-library.yaml
  when: "{{item}} == {{ansible_hostname}}"

But I always get:

fatal: [xxx.xxx.xxx.xxx]: FAILED! => {"failed": true, "msg": "ERROR! 'item' is undefined"}

When this project was just one device, we used with_items: stuff.yaml all the time and it worked just fine.

My question is this: what do I have to put in place of {{item}}, or is there a better way?

Answer 1

From this statement:

The play itself is supposed to figure out which library matches the device, use that library's variables and none of the other ones.

I conclude you are trying to replicate one of the most fundamental features of Ansible.

What you should do:

1. create a subdirectory host_vars in your Ansible project directory;
2. move the files containing variable definitions to the host_vars directory;
3. make sure the above file names match exactly the host names used by Ansible to refer to the target machines (no .yaml extension);
4. delete all manual include directives from your playbook;
5. run the playbook.

Alternatively to cover several servers you can do the same using group_vars subdirectory and name the files according to the group names defined in the inventory file.

Refer to the documentation for more information.