How to run only one Ansible role?

Question

Ansible

Good evening!
There is a project for Ansible which contains several roles. How to run a playbook so that only one role is executed, but understands the variables?
site.yml looks like this:

---
- hosts: demo
  remote_user: jenkins
  become: yes
  become_method: sudo

  roles:
    - role1
    - role3
    - role4
    - role5
    - role6
    - role7

I start now like this:
ansible-playbook -i hosts site.yml
And I just put the "#" symbol in front of those roles that do not need to be performed now. But I think there is another way.

Answer 1

If people before you did everything right, then in the role1 directory (let’s say it needs to be executed) there should be a tasks directory, and in it the main.yml file, so you need to pass it as an argument to the command
ansible-playbook -i hosts role1/tasks/main.yml

Answer 2

Maybe a little off topic. Interested in Ansible .
What is the meaning of roles? I have a strategy to solve the problem with one playbook. (circulation problem).
On Git, take a look at my train of thought. Messed up the project , maybe not?

Answer 3

Solved this question like this:
site.yml looks like this:

---
- hosts:  demo
  remote_user: jenkins
  become: yes

  roles:
  - '{{ ROLE }}'

I run it like this:
In order to run on another and on different groups of hosts, you need to bring site.yml to this form:

---
- hosts:  '{{ TARGETIP }}'
  remote_user: jenkins
  become: yes

  roles:
  - '{{ ROLE }}'

Run like this:

ansible-playbook -i hosts site.yml -e "ROLE=role1" -e "TARGETIP=demo"

Answer 4

Use tags.
Like this:
...
roles:
- { role: role1, tags: role1}
- { role: role2, tags: role2}
- { role: role3, tags: role3}
...
Execute
ansible-playbook -i hosts site. yml -t role1