Ansible Playbook learning the Agentless DevOps tooL

This section for those who already have idea about Ansible .

Important :    I just want to start  about Ansible  Playbook

like in  :

Puppet  :    Module

Chef       :   CookBook

Same  ansible  has ===>>

Ansible   :  Playbook 

Ansible  Playbook  Divided  into 3  section : 

1.   Target  section  :

Note:    This is similar  to  nodes.pp in  puppet  and run-list in chef

target section  generally means on which  target system this playbook is going  to execute all the stuff.

2.   Variable Section  

This is not manodatory but which you can use in playbook as general placeholder

3.   Task Section 

List  of modules in order to run 

Note:  playbooks are written in YAML language  that is  Yet Another markup Language

Here is  sample of  Ansible playbook

root@ashulinux:/etc/ansible# cat  test1.yml 
---
 - hosts: all
   user: root
   vars:
    motd_warning: 'knowledge is power !!i n\'
   tasks:
   - name: sample motd
     copy:
      dest: /etc/motd
      content: "{{ motd_warning }}"

Note :  To Run ansible playbook

root@ashulinux:/etc/ansible# ansible-playbook  test1.yml 
 ____________
< PLAY [all] >
 ------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


 _________________
< GATHERING FACTS >
 -----------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


ok: [192.168.0.46]
ok: [192.168.0.41]
ok: [192.168.0.80]
ok: [192.168.0.167]
 ___________________
< TASK: sample motd >
 -------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


ok: [192.168.0.80]
ok: [192.168.0.167]
ok: [192.168.0.41]
ok: [192.168.0.46]
 ____________
< PLAY RECAP >
 ------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


192.168.0.167              : ok=2    changed=0    unreachable=0    failed=0
192.168.0.41               : ok=2    changed=0    unreachable=0    failed=0
192.168.0.46               : ok=2    changed=0    unreachable=0    failed=0
192.168.0.80               : ok=2    changed=0    unreachable=0    failed=0

Run Ansible Playbook in verbose mode


root@ashulinux:/etc/ansible# ansible-playbook  test1.yml -v 
 ___________
< PLAY [lw] >
 -----------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


 _________________
< GATHERING FACTS >
 -----------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


ok: [192.168.0.80]
ok: [192.168.0.167]
 ___________________
< TASK: sample motd >
 -------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


ok: [192.168.0.80] => {"changed": false, "dest": "/etc/motd", "gid": 0, "group": "root", "md5sum": "21984c82bbf4ebb7e6dad67d0fc652f7", "mode": "0644", "owner": "root", "path": "/etc/motd", "secontext": "system_u:object_r:etc_runtime_t:s0", "size": 21, "state": "file", "uid": 0}
ok: [192.168.0.167] => {"changed": false, "dest": "/etc/motd", "gid": 0, "group": "root", "md5sum": "21984c82bbf4ebb7e6dad67d0fc652f7", "mode": "0644", "owner": "root", "path": "/etc/motd", "secontext": "system_u:object_r:etc_runtime_t:s0", "size": 21, "state": "file", "uid": 0}
 ____________
< PLAY RECAP >
 ------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||


192.168.0.167              : ok=2    changed=0    unreachable=0    failed=0
192.168.0.80               : ok=2    changed=0    unreachable=0    failed=0

root@ashulinux:/etc/ansible# 

Run Ansible playbook in  step mode

root@ashulinux:/etc/ansible# ansible-playbook  test1.yml --step 

Note:  ansible playbook for  apache  web server configuration  management 

root@ashulinux:/etc/ansible# cat  install_apache.yml 

# installing  apache

--- 

- hosts: adhoc

  user: root

  tasks:

  - name: installing package

    action: yum name=httpd state=installed

  - name: start service 

    service: 

     name: httpd 

     state: restarted

  - name: check yum repo

    copy: src=/info.txt dest=/var/www/html/index.html

Important:

Here  hosts == pointing to  all  hosts inside   /etc/ansible/hosts

Note:  One more sample file:

- name: install and configure webservers
hosts: apache
remote_user: ec2-user
sudo: yes
roles:
   - apache
-------------------------------------------
-------------------------------------------
If we want to log into our host machines using a different username and with sudo privileges, we need to use the “remote_user” and “sudo: yes” parameter in our site.yml file. There can be additional parameters too, but they’re not needed right now. Here, we have also defined roles granted to hosts in the [webservers] group.
------------------------------------------
------------------------------------------


Method for error free playbook methods according to YAML syntax:

i) creating  apache web server yml file

[root@be04c6686478 ansible]# cat  apache_final.yml 
---
- hosts: webserver
  vars:
    http_port: 80
    max_client: 300
  remote_user: root
  tasks:
  - name: installing  httpd and check
    yum:
      name: httpd
      state: latest
  - name: start the apache service
    service:
      name: httpd
      state: started
      enabled: yes


ii)  Run yml file

[root@be04c6686478 ansible]# ansible-playbook  apache_final.yml

PLAY [webserver] **************************************************************

GATHERING FACTS ***************************************************************
ok: [192.168.0.183]

TASK: [installing  httpd and check] *******************************************
ok: [192.168.0.183]

TASK: [start the apache service] **********************************************
changed: [192.168.0.183]

PLAY RECAP ********************************************************************
192.168.0.183              : ok=3    changed=1    unreachable=0    failed=0




iii)   managing  containers using ansible  

1.  launching  containers 

---

 - hosts: test

   remote_user: root

   tasks:

    - name: creating   container 

      docker_container:

       name: ashutoshhtest1

       image: centos6shh

       detach: true 

  

       2.   Launching  multiple containers      

---

 - hosts: test

   remote_user: root

   tasks:

    - name: creating   container 

      docker_container:

       name: "container{{ item }}"

       image: centos6shh

       detach: true 

       

    

      with_sequence: count=6

   3.   removing containers 

---

 - hosts: test

   remote_user: root

   tasks:

    - name: removing container

      docker_container:

       name: ashutoshh

       state: absent       

   4.   starting containers 

---

 - hosts: test

   remote_user: root

   tasks:

    - name: starting   container 

      docker_container:

       name: ashutoshhne

       image: centos6shh

       state: started

5.   stoping containers 

---

 - hosts: test

   remote_user: root

   tasks:

    - name: stop a running container

      docker_container:

       name: ashutoshhne

       state: stopped

6.  container with volume 

---

 - hosts: test

   remote_user: root

   tasks:

    - name: creating   container with volume

      docker_container:

       name: ashutoshhtest2

       image: centos6shh

       command: ping localhost

       detach: true 

       volumes:

        - /data