Ansible Tutorial - How To Define a Ansible Register Variable in Playbook

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Ansible registers module used to capture / store the output of a task/command.it is similar to variable declarations we can define the value in different scenarios like a conditional, logging etc.

for example we echo uptime and hostname, Following Syntax :

register: uptime

Here uptime is value of register variable, we can define any suitable value. At the last we use debug module with variable name.  

To create a playbook with suitable name, we create a register.yml file under ansible configuration directory

cd /etc/ansiblevi register.yml

---

- hosts: all

  tasks:

  - name: System Uptime

    command: uptime

    register: uptime

  - debug: var=uptime

-name: System Uptime  is a task name, 

command: uptime  , command is module name and uptime is linux system command

register: uptime , uptime is register variable value, we can use any suitable value 

To run playbook using ansible-playbook command, for help of ansible-playbook you can use -h option

ansible-playbook  -h

To run ansible playbook

ansible-playbook registe.yml

To run ansible playbook on single hosts of inventory using  -l option,

172.17.20.98 is hosts IP of our Ansible Inventery

ansible-playbook -l 172.17.20.98 register.yml

We can add stderr, stderr_lines, stdout, stdout_lines for filter

We will use stdout for filter the result, something like this example

Video Tutorial : 

---

- hosts: all

  tasks:

  - name: System Uptime

    command: uptime

    register: uptime

  - debug: var=uptime.stdout

Multiple register variable :

---

- hosts: 127.0.0.1

  tasks:

  - name: System Uptime

    command: uptime

    register: uptime

  - name: System Hostname

    command: hostname

    register: host

  - debug: var={{ item }}

    loop:

      - uptime.stdout

      - host.stdout

ansible-playbook registe.yml

Thanks

End of this ansible register variables tutorial,  we need your support so i request you to please comment if something missed by me, and share and like this post aslo 

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