Linux · Cheatsheet

Ansible Cheatsheet

Inventory, ad-hoc, playbooks, roles, vault, check mode, and the magic vars (hostvars, groups) every playbook author needs.

Updated 2026-05-21 8 min

Inventory & ad-hoc

ansible-inventory -i hosts.ini --list	Render inventory as JSON
ansible-inventory --graph	Tree view of groups + hosts
ansible all -m ping	Connectivity test (uses python on target)
ansible web -m setup	Gather all facts from group 'web'
ansible db -m shell -a 'systemctl status postgresql'	Run a shell command
ansible web -m copy -a 'src=./nginx.conf dest=/etc/nginx/nginx.conf' --become	Copy + sudo

ansible-playbook site.yml -i hosts.ini	Run a playbook
ansible-playbook site.yml --check --diff	Dry-run + show diffs (best practice)
ansible-playbook site.yml --limit web1	Limit to one host
ansible-playbook site.yml --tags 'deploy,restart'	Run only tagged tasks
ansible-playbook site.yml --skip-tags 'slow'	Skip tagged tasks
ansible-playbook site.yml --start-at-task 'Install nginx'	Resume from a task
ansible-playbook site.yml -vvv	Verbose (4 levels: v, vv, vvv, vvvv)

ansible-playbook site.yml -e 'env=prod version=1.2'	Extra vars (highest precedence)
ansible-playbook site.yml -e @prod.json	Extra vars from file
{{ ansible_hostname }} / {{ ansible_default_ipv4.address }}	Common facts
{{ hostvars['web1'].ansible_distribution }}	Access another host's facts
{{ groups['db'] }}	List of hosts in group 'db'
{{ lookup('env', 'HOME') }}	Read env var on controller

ansible-galaxy init roles/nginx	Scaffold a role
ansible-galaxy collection install community.kubernetes	Install collection
ansible-galaxy install -r requirements.yml	Install role/collection deps
roles/<name>/{tasks,handlers,defaults,vars,files,templates,meta}	Standard role layout

ansible-vault create secrets.yml	Create encrypted file
ansible-vault edit secrets.yml	Edit
ansible-vault view secrets.yml	View
ansible-vault encrypt_string 'mysecret' --name 'db_pass'	Inline-encrypted value
ansible-playbook site.yml --ask-vault-pass	Prompt for password
ansible-playbook site.yml --vault-password-file ~/.vault_pass	Read from file

become: true become_user: postgres	Privilege escalation
when: ansible_os_family == 'Debian'	Conditional execution
loop: "{{ packages }}"	Iterate over a list
register: result / debug: var=result	Capture + print task output
notify: 'restart nginx'	Trigger handler on change
block / rescue / always	Try/catch for tasks
delegate_to: localhost	Run task on controller, not target

ansible.builtin.apt / yum / dnf	Package management
ansible.builtin.service / systemd	Manage services
ansible.builtin.template	Jinja2 template → file
ansible.builtin.lineinfile / blockinfile	Idempotent file edits
ansible.builtin.cron	Manage crontab entries
community.general.timezone	Set system timezone
kubernetes.core.k8s	Apply Kubernetes manifests

forks = 50 (ansible.cfg)	Parallelism — default is 5
strategy: free	Hosts proceed independently (vs default linear)
pipelining = True	Fewer SSH calls per task (2-4x faster)
fact_caching = jsonfile	Cache facts across runs

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