Ansible closer look task control

Simple loops :-

this will iterate from a list of items for a task.

backend concept:-

It uses  with_items as loop starter and data is stored in  item  


Demo 1:  


-bash-4.3$ cat loops/simple.yml
--- - hosts: localhost
   become: true
   tasks:
    - name: starting service
      service:
       name: "{{ item }}"
       state: restarted
       enabled: yes
      with_items:
       - httpd
       - sshd


Using internal variables :


 Demo 2: 


-bash-4.3$ cat  loops/simple1.yml ---
 - hosts: localhost
   become: true
   vars:
    x:
     - httpd
     - sshd
   tasks:
    - name: starting service
      service:
       name: "{{ item }}"
       state: restarted
       enabled: yes
      with_items: "{{ x }}"
 


Using  external variables : 


demo 3: 


-bash-4.3$ cat loops/simple2.yml ---
 - hosts: localhost
   become: true
   tasks:
    - name: including variable
      include_vars: vars/var.yml
    - name: starting service
      service:
       name: "{{ item }}"
       state: restarted
       enabled: yes
      with_items: "{{ x }}"
 

-bash-4.3$ cat  loops/vars/var.yml x:
 - httpd
 - sshd


Hash oriented or Key value based simple loop:


Demo :

-bash-4.3$ cat  loops/keyval.yml
---
 - hosts: localhost
   become: true
   tasks:
    - name: adding users and assigining them in a group
      user:
       name: "{{ item.name }}"
       state: present
       groups:  "{{ item.groups }}"
      with_items:
       - {name: 'raj', groups: 'root'}
       - {name: 'roahn', groups: 'wheel'}
       - {name: 'rajesh', groups: 'bin'}
 


Time for nested loops 

-bash-4.3$ cat  loops/nested.yml ---
 - hosts: localhost
   become: true
   vars:
    x:
     - key1
     - key2
     - key3

   tasks:
    - name: adding in line
      lineinfile: dest=/tmp/{{ item[0] }}/a.txt line={{ item[1] }} state=present
      with_nested:
       - ['user1','user2','user3']
       - "{{ x }}"
 


Here : 
 all 3 keys are added to each user file 


Demo 2:

-bash-4.3$ cat loops/nestedbug.yml ---
- name: Demo of with_nested
  hosts: localhost
  become: true

  vars:
    list1: [1, 2, 3]
    list2: [a, b, c, d]

  tasks:
    - name: Printing message
      debug: msg="Values are {{item[0]}} and {{item[1]}}"
      with_nested:
        - list1
        - list2
 

ANSIble tasks with condition :

 As in normal programming language we are using we are using when it comes to project with ansible it also check the same thing :

Demo: 

-bash-4.3$ cat condition/when1.yml ---
 - hosts: localhost
   become: true
   vars:
    x: true

   tasks:
    - name: pring message
      debug: msg="hello world this is ansible"
      when: x