Ansible ad hoc commands are one-liners designed to achieve a very specific task they are like quick snippets and your compact swiss army knife when you want to do a quick task across multiple machines.
To put simply, Ansible ad hoc commands are one-liner Linux shell commands and playbooks are like a shell script, a collective of many commands with logic.
Ansible ad hoc commands come handy when you want to perform a quick task.
Task-01
Write an ansible ad hoc ping command to ping 2 servers from inventory file
ansible server1:server2 -m ping
Write an ansible ad hoc command to check uptime
ansible -i /path/to/inventory/file all -m command -a uptime
If your inventory is in the default location (/etc/ansible/hosts or ~/.ansible.cfg) you can omit the -i option and the path altogether.
Ansible ad hoc command to check the amount of free memory or the amount of memory used by hosts.
ansible all -a "free -m"
Ansible ad hoc command to get physical memory allocated to the host
ansible all -m shell -a "cat /proc/meminfo|head -2"
Ansible command to check the disk space on all hosts in an inventory file
ansible all -m shell -a 'df -hT'
Ansible command to list all the running processes on a specific host in an inventory file
ansible all -m shell -a "ps aux"
Ansible command to run a shell command with sudo on all hosts in an inventory file
ansible all -m shell -a "sudo apt-get update"
Ansible command to show all 2 servers’ python versions.
ansible all -m shell -a "sudo python3 --version"
Ansible command to check the status of a specific service on all hosts in an inventory file
ansible all -m service -a "name=apache"
The following ad hoc command with copy module copies the file from Src location on the local control machine to the specified location on the remote server
ansible -i inventory_file all -m copy -a 'src=/local/path/to/file dest=/remote/path/to/file mode=0644'
First create a simple text file at any location, here create a text file at /home/ubuntu location with name file.txt.
Check if the file is successfully copied to all the servers with the ‘sudo ls command’
ansible all -m shell -a 'sudo ls /home/ubuntu'
Create a file with 755 permission using ansible ad hoc commands
ansible all -m file -a "path=/home/ubuntu/ansible state=directory mode=0755" -b
