Variables in Ansible

in case we need to install bulk of packages , we will need a variable with the packages names

root@dcex1510ctrl001:~# cat ansible/playbooks/variables.yaml

- name: Ansible playbook to study variables

  hosts: localhost

  vars:

    courses:

      - ansible

      - terraform

      - docker

  tasks:

  - name: Display Value

    debug:

      msg: "{{ courses[0] }}"

root@dcex1510ctrl001:~# ansible-playbook ansible/playbooks/variables.yaml

[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

PLAY [Ansible playbook to study variables] ***************************************************************************************

TASK [Gathering Facts] ***********************************************************************************************************

ok: [localhost]

TASK [Display Value] *************************************************************************************************************

ok: [localhost] => {

    "msg": "ansible"

}

PLAY RECAP ***********************************************************************************************************************

localhost                  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

We will create a variable with kind array and a loop to install some packages

root@dcex1510ctrl001:~/ansible/playbooks/variablesPlaybooks# cat installPackagesLoop.yaml             

- name: Ansible playbook to install 2 packages and remove them through variables and loops

  hosts: client01

  vars:

    packages:

      - apache2

      - mysql-client

  tasks:

  - name: Install the packages

    apt:

      name: "{{ item }}"

      state: present

    loop: "{{ packages }}"

  - name: Remove the packages

    apt:

      name: "{{ item }}"

      state: absent

    loop: "{{ packages }}"

root@dcex1510ctrl001:~/ansible/playbooks/variablesPlaybooks# ansible-playbook -i /root/ansible/hosts/hosts.ini installPackagesLoop.yaml

PLAY [Ansible playbook to install 2 packages and remove them through variables and loops] ****************************************

TASK [Gathering Facts] ***********************************************************************************************************

ok: [10.11.25.67]

TASK [Install the packages] ******************************************************************************************************

ok: [10.11.25.67] => (item=apache2)

changed: [10.11.25.67] => (item=mysql-client)

TASK [Remove the packages] *******************************************************************************************************

changed: [10.11.25.67] => (item=apache2)

changed: [10.11.25.67] => (item=mysql-client)

PLAY RECAP ***********************************************************************************************************************

10.11.25.67                : ok=3    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

We can create variable file for ansible like terraform, let's do it here 

root@dcex1510ctrl001:~/ansible/playbooks/variablesPlaybooks# cat vars.yaml

server_name: Test_VM1

server_port: 443

root@dcex1510ctrl001:~/ansible/playbooks/variablesPlaybooks# cat variables.yaml

- name: Ansible playbook to study variables

  hosts: localhost

  tasks:

  - name: Display Server Name

    debug:

      msg: "{{ server_name }}"

  - name: Display Server Name

    debug:

      msg: "{{ server_port }}"

root@dcex1510ctrl001:~/ansible/playbooks/variablesPlaybooks# ansible-playbook -e "@vars.yaml" variables.yaml

[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

PLAY [Ansible playbook to study variables] ***************************************************************************************

TASK [Gathering Facts] ***********************************************************************************************************

ok: [localhost]

TASK [Display Server Name] *******************************************************************************************************

ok: [localhost] => {

    "msg": "Test_VM1"

}

TASK [Display Server Name] *******************************************************************************************************

ok: [localhost] => {

    "msg": 443

}

PLAY RECAP ***********************************************************************************************************************

localhost                  : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

We can add the variable file in our playbook and the playbook will read the variables from it

root@dcex1510ctrl001:~/ansible/playbooks/variablesPlaybooks# cat variables.yaml

- name: Ansible playbook to study variables

  hosts: localhost

  vars_files:

    vars.yaml

  tasks:

  - name: Display Server Name

    debug:

      msg: "{{ server_name }}"

  - name: Display Server Name

    debug:

      msg: "{{ server_port }}"

root@dcex1510ctrl001:~/ansible/playbooks/variablesPlaybooks# ansible-playbook variables.yaml

[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

PLAY [Ansible playbook to study variables] ***************************************************************************************

TASK [Gathering Facts] ***********************************************************************************************************

ok: [localhost]

TASK [Display Server Name] *******************************************************************************************************

ok: [localhost] => {

    "msg": "Test_VM1"

}

TASK [Display Server Name] *******************************************************************************************************

ok: [localhost] => {

    "msg": 443

}

PLAY RECAP ***********************************************************************************************************************

localhost                  : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0