AD‑HOC COMMANDS

Introduction

An Ansible ad‑hoc command is a one‑line command used to perform quick tasks on one or more remote servers without writing a playbook.

It is mainly used for:

• Quick checks
• Small changes
• Troubleshooting
• Immediate actions

Why Use Ad‑hoc Commands?

• You don’t want to create a YAML playbook
• The task is temporary or one‑time
• You need fast execution
• You want to test connectivity or configuration

Ad‑hoc Command Examples

1. Ping all servers

   ansible -m ping all

   • -m = module
   • all = all servers
2. Ping a specific group

   ansible -m ping node

   • node = group name
   • Hosts are added under this group
3. Check disk space

   ansible -m command -a "df -h" all

   • -a = pass the command
   • command = command module
   • df = check disk space
4. Use shell with pipeline

   ansible -m shell -a "df -h | ls" all

   • shell = command module
   • Pipelines can be used
5. Install Apache using apt

   ansible node -m apt -a "name=apache2 state=present update_cache=yes" -b

   • apt = module to install Apache
   • name = package name
   • state = package state
   • update_cache = updates apt cache
   • -b = run with elevated privileges
6. Restart a service

   ansible -m service -a "name=apache2 state=restarted" all

   • service module = restart Apache
7. Copy a file

   ansible -m copy -a "src=config dest=/tmp" all

   • copy module = copy files
   • src = source file
   • dest = destination path
8. Create a directory

   ansible -m file -a "dest=/tmp/ak mode=644 state=directory" all

   • file module = create directories
   • dest = directory path
   • mode = permissions
   • state = directory state
9. Create a template

   ansible -m template -a "src=template dest=/tmp/ak" all

   • template module = create template file
   • src = source template
   • dest = destination path
10. List all hosts

    ansible --list-hosts all

    • Shows all hosts in the hosts file
11. Create a user

    ansible -m user -a "name=devops state=present groups=sudo append=yes" all

    • user module = create a user
    • name = username
    • state = user state
    • groups=sudo = add to sudo group
    • append=yes = keep existing groups
12. Install multiple packages

    ansible -m apt -a "name='vim,git,curl' state=present update_cache=yes" -b all

    • Installs multiple packages
    • -b = root privileges
13. Delete a file or directory

    ansible -m file -a "path=/tmp/oldfile state=absent" all

    • state=absent = delete file or directory
    • path = file or directory path
14. Fetch files from remote hosts

    ansible -m fetch -a "src=/etc/hosts dest=~/hosts_backup/ flat=yes" all

    • fetch module = copy remote files to local
    • flat=yes = avoids creating directories
15. Synchronize directories

    ansible -m synchronize -a "src=/local/dir dest=/remote/dir" all

    • synchronize module = sync directories
    • src = source directory
    • dest = destination directory
    • Uses rsync