使用 Ansible 从服务列表中仅启动特定的 systemd 服务

Question

I have list of systemd services defined as

vars:
  systemd_scripts: ['a.service', 'b.service', 'c.service']

Now I want to stop only a.service from above list. How this can be achieved using systemd _module?

Answer 1

What are you trying to achieve? As written, you could just do:

- name: Stop service A
  systemd:
    name: a.service
    state: stopped

If instead you mean "the first service", use the first filter or an index:

- name: Stop first service
  systemd:
    name: "{{ systemd_scripts | first }}"
    state: stopped

OR

- name: Stop first service
  systemd:
    name: "{{ systemd_scripts[0] }}"
    state: stopped

Answer 2

Your question is very vague and unspecific. However, parts of your question could be answered with the following approach

- name: Loop over service list and stop one service
  systemd:
    name: "{{ item }}"
    state: stopped
  when:
    - systemd_scripts[item] == 'a.service'
  with_items: "{{ systemd_scripts }}"

You may need to extend and change it for your needs and required functionality.

Regarding discovering, starting and stopping services via Ansible facts ( service_facts ) and systemd you may have a look into

Further readings

• Ansible: How to get disabled but running services?
• How to declare a variable for service_facts ?
• How to check service exists and is not installed in the server using service_facts module in an Ansible playbook?