Ansible snippets

Systemd

Randomize timer

Create /var/ansible/files/systemd/fstrim.conf

[Timer]
RandomizedDelaySec=3h

Playbook:

  tasks: 

     - name: check if /etc/systemd/system/fstrim.timer.d/ exists
       stat:
         path: /etc/systemd/system/fstrim.timer.d/
       register: override_dir

     - name: create /etc/systemd/system/fstrim.timer.d/
       file:
         path: /etc/systemd/system/fstrim.timer.d/
         state: directory
       when: override_dir.stat.exists == False

     - name: add fstrim.timer override
       copy:
         src: /var/ansible/files/systemd/fstrim.conf
         dest: /etc/systemd/system/fstrim.timer.d/override.conf
       notify: daemon-reload

   handlers:

     - name: daemon-reload
       systemd:
         daemon_reload: yes

Lineinfile

• Lineinfile documentation

Quoting fun with lineinfile regex

- name: fix the needrestart config
  lineinfile:
    dest: /etc/needrestart/needrestart.conf
    state: present
    regexp: '^#\$nrconf{restart}'
    line: '$nrconf{restart} =  ''a'''
   when: ansible_distribution == 'Ubuntu' and ansible_distribution_major_version == '22'

Comment out a line

- name: comment out a line
  lineinfile:
    dest: /etc/needrestart/needrestart.conf
    state: present
    backrefs: true
    regexp: '^(foo.*)'
    line: '# \1'

Check for string in file

   - name: Check for rotate setting
     lineinfile:
       path: "Template:Rotatepath"
       regex: '^ *rotate 180$'
       state: absent
     register: result

   - debug: msg="Template:Inventory hostname Template:Result.found"

Remove part of string

use replace instead

Files

Check if a file exists

 - name: check for a file
   stat:
     path: /etc/fstab
   register: fstab

- name: print message if exists
  ansible.builtin.debug:
    msg: "File /etc/fstab exists"
  when: fstab.stat.exists

Check if copy updated a file

 - name: copy file
  copy:
    src: foo
    dest: /tmp/bar
  register: newfile

  - name: quit play for this host if file was up to date
    meta: end_host
    when: not newfile.changed

Modify permissions on files in a directory

ansible.builtin.file: 
mode: gw=rwX

or

- name: fix rights
  file:
    path: "Template:Item.path"
    mode: u=rw,g=rw,o=r
  loop: "Template:Query('filetree', '/tmp/foo')"
  loop_control:
    label: "/Template:Item.path"

Check if a command exists

   - name: check if mysqld is installed
     shell: which mysqld > /dev/null 2>&1 
     ignore_errors: true
     changed_when: false
     register: mysqld
     failed_when: mysqld.rc == 2

Systemd

Check if systemd service exists

- name: check for service
    name: foo
  register: servicestate

1. not-found or loaded

- name: show status
  debug:
    var: servicestate.status.LoadState

Check if systemd service is enabled

- name: check for service
    name: foo
  register: servicestate
  when: servicestate.status.LoadState == 'loaded'

- name: show status
  debug:
    var: servicestate.status.UnitFileState