Ansible

• Cgroups and callbacks

sudo cgcreate -a user:user -t user:user > -g cpuacct,memory,pids:ansible_profile

# on ansible.cfg
callback_whitelist=cgroup_perf_recap[callback_cgroup_perf_recap]control_group=ansible_profile

cgexec -g cpuacct,memory,pids:ansible_profile > ansible-playbook deploy_webservers.yml

• Listen on handlers

# Listening to the "My handlers" event
- name: Listening to a notification
  debug:
    msg: First handler was notified
  listen: My handlers

• Add callback to ansible.cfg

callback_whitelist=timer, profile_tasks

• Concatenate 2 Arrays:

"{{ apache_base_packages | union(apache_optional_packages) }}"

• Avoid to fail by a lookup error

{{ lookup('file', 'my.file', errors='warn') | default("Default file content") }}

• Execute commands from Lookup on control node

{{ query('pipe', 'ls files') }}

• from yaml

my_yaml: "{{ lookup('file', '/path/to/my.yaml') | from_yaml }}"

• Loop over file lines

- name: Prints the first line of some files
  debug:
    msg: "{{ item[0] }}"
  loop:
    - "{{ query('lines', 'cat files/my.file') }}"

• dig over a host

# It needs python3-dns rpm

- name: Determinte if host's ip address is private
  debug:
    msg: "{{ lookup('dig', ansible_facts['hostname'] ) | ipaddr('private') }}"

"{{ lookup('dig', 'example.com', '@4.4.8.8,4.4.4.4) }}"

• Fail all if 1 steps fails

max_fail_percentage: 0

• Interacting with Tower API

- name: Delete an existing Ansible Tower Job Template using the uri module
  uri:
    url: "https://{{ tower_fqdn }}/api/v2/job_templates/{{ copy_template_name | urlencode }}/"
    validate_certs: no
    method: DELETE
    return_content: yes
    force_basic_auth: yes
    user: "{{ tower_user }}"
    password: "{{ tower_password }}"
    status_code: 204

• Sample of SmartHostFilter

ansible_facts.ansible_distribution:RedHat

• Change TLS cert for tower

semanage fcontext -a -t cert_t "/etc/tower(/.*)?"
restorecon -FvvR /etc/tower/
rm /etc/tower/tower.*
ipa-getcert request -f /etc/tower/tower.cert \> -k /etc/tower/tower.key
ansible-tower-service restart

• Grant role admin on Team

tower-cli role grant --user 'daniel' \> --target-team 'Developers' --type 'admin'