can I embed inventory inside the playbook?

Question

I want to have build some minimal example for ansible playbook, thus I do not want to have multiple files and dirs for each playbook.

I would like to make the single file contain everything.

I knew I can use localhost like following, then I can just run the playbook without inventory.

- name: Example playbook
  hosts: localhost
  connections: local
  tasks:
    - ansible.builtin.debug: "hello!"

I wonder how can I do similar thing but also define a simple inventory inside the playbook:

all:
  hosts:
    localhost:
      ansible_connection: local
    host1:
      http_port: 80
      maxRequestsPerChild: 808
      ansible_host: 127.0.0.2

the hosts keyword in the playbook seems only accept list of strings

Answer 1

You cannot "embed" an inventory in the playbook, but you could dynamically build an inventory using the add_host module.

E.g:

- hosts: localhost
  gather_facts: false
  tasks:
  - add_host:
      name: newhost1
      groups:
      - webservers
      http_port: 80
      maxRequestsPerChild: 808
      ansible_host: 127.0.0.2

- hosts: webservers
  gather_facts: false
  tasks:
  - ping:

Running this produces:

PLAY [localhost] ***************************************************************

TASK [add_host] ****************************************************************
changed: [localhost]

PLAY [webservers] **************************************************************

TASK [ping] ********************************************************************
ok: [newhost1]

PLAY RECAP *********************************************************************
localhost                  : ok=1    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   
newhost1                   : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0