What is Ansible Playbooks part-7

 What is Ansible Playbooks.

We have preferred playbook where we need to perform any task on repeat basis means suppose we want to take backup of our all server, we can write a playbook for that. Playbooks are written in YAML language.

debug module
yum
shell
command
template
user:
stat - check if a file exists
apt
copy
service
file
lineinfile
archive/unarchive
git
package
ec2

##############################

debug module

vars:

    - tomcat_url: http://tomcat.com

  tasks:

  - name: install tomcat

    debug:

      msg: "{{ tomcat_url }}"

#################################

 yum/apt/package:

     name: httpd

     state: present

#################################

shell

- name: Change the working directory to somedir/ before executing the command.

  shell: somescript.sh >> somelog.txt

  args:

    chdir: somedir/

#################################

command

- name: Run the app installer

  command: "/app/install.sh"

or

- name: return motd to registered var

  command: cat /etc/motd

  register: mymotd

#################################

template

- name: Ensure MOTD file is in place

  template:

    src: templates/motd.j2

    dest: /etc/motd

#################################

user:

- name: Ensure user ricardo exists

  user:

    name: ricardo

    group: users

    groups: wheel

    uid: 2001

    password: "{{ 'mypassword' | password_hash('sha512') }}"

    state: present

##################################

stat:

- name: Check that the somefile.conf exists

stat

    path: /etc/file.txt

    register: stat_result

###################################

copy

  copy:

    src: files/motd

    dest: /etc/motd

####################################

service

service:

    name: sshd

    state: started

######################################

file (delete)

 file:

    path: /tmp/Shashi.txt

    state: absent

########################################

lineinfile

- name: Ensure root cannot login via ssh

  lineinfile:

    path: /etc/ssh/sshd_config

    regexp: '^PermitRootLogin'

    line: PermitRootLogin no

    state: present

#########################################

archive/unarchive

- name: Extract contents of app.tar.gz

  unarchive:

    src: /tmp/app.tar.gz

    dest: /app

    remote_src: yes

#########################################

git

- git:

    repo: 'https://foosball.example.org/path/to/repo.git'

    dest: /srv/checkout

    version: release-0.22

########################################

ec2:

 - name: create an ec2 instance

      ec2:

         key_name: "{{ keypair }}"

         group: "{{ security_group }}"  # security group name

         instance_type: "{{ instance_type}}"

         image: "{{ image }}"

         wait: true

         region: "{{ region }}"

         count: 1  # default

         count_tag:

            Name: Demo

         instance_tags:

            Name: Demo

         vpc_subnet_id: subnet-fb2bf1da

         assign_public_ip: yes

1)  -C option this cause ansible to report what changes would have occurred if the playbook were executed. but does not make any actual changes to managed hosts.  

# ansible-playbook  -C  webserver.yml

2) one by one task execute and showing Y or N Option. 

# ansible-playbook --step  webserver.yml

3) playbook syntax check. 

# ansible-playbook  webserver.yml  --syntax-check

Ansible playbook structure flow:-

---

- hosts: jenkins                      ===> Remote name/group name 

  gather_facts: True                ===> default Variable True /False

  become: yes                        ===> root user privilege

  # remote_user: ansadm      ===> remote user defined 

  vars:                                   ===> Variable defined

          my_content: "this file created using var concept"   ===> variable name "my_content"  

  tasks:                                                        ===> First Play 1

   - name: create a file var_file.txt..        ===>  First Task and  Task Name

     copy:                                                    ===>  Module name

            dest: /tmp/var_file.txt

            content: "{{ my_content }}"

   - name: install nginx service                ===> Second Task 

     yum:

         name: httpd

         state: present

   - name: httpd service start                    ===> third Task

     service:

          name: httpd

          state: started

- name: remove file                                ===> fourth Task

   file:

          path: /tmp/Shashi.txt

          state: absent

 1. How to check playbook content . 

# ansible-playbook httpd.yml --syntax-check

# ansible-playbook -i host httpd.yml

        OR

# ansible-playbook httpd.yml

2. Logs redirect to output.log file.

# ansible-playbook httpd.yml | tee -a output.log

yum state :- 

• latest.
•  present.
• installed.
• absent.
• removed.

Services : state :-

• reloaded
• restarted
• running
• started
• stopped

1.  Restarting a Network Interface eth0
---
- name: Restart network service for interface eth0
  service:
    name: network
    state: restarted
    args: eth0

2. Copy Module
Copying Files from Local to Remote Linux
 
---
- name: Copy file with owner and permissions
  copy:
    src: /etc/files/jk.conf
    dest: /srv/jk.conf
    owner: shashi
    group: shashi
    mode: '0644'
 
3. File Module.

i) Perform Linux File Permissions.
---
- name: Change file ownership, group, and permissions
  file:
    path: /etc/jk.conf
    owner: root
    group: root
    mode: '0644'
 
ii) Delete Linux File.
---
- name: Remove file (delete file)
   file
     path: /etc/shashi.conf
     state: absent
 
iii) Create a Directory.
---
- name: create a directory if it doesn’t exist
  file:
    path: /etc/mydirectory
    State: directory
    mode: '0777'
 
iv) Recursiverly Delete a Directory.
---
- name: Recursively deleting a  directory
  file:
    path: /etc/shashi.conf
    state: absent
 
4. Lineinfile Module.
 
i) Manipulate Files in Linux.
---
 - name: Ensure SELinux is set to enforcing mode
  lineinfile:
    path: /etc/selinux/config
    regexp: '^SELINUX='
    line: SELINUX=disabled
 
The play above sets SELINUX value to disabled.
SELINUX=disabled
 
ii) Alter Files in Linux.
---
- name: Add a line to a file if the file does not exist, without         passing regexp
  lineinfile:
    path: /etc/hosts
    line: 10.200.50.51 shashi.com
    create: yes
 
This adds the entry 10.200.50.51 shashi.com to the /etc/hosts file.
 
5. Archive Module.
 
i) Create a Archive File.
- name: Compress directory /path/to/shashi_dir/ into /path/to/shashi.tgz
  archive:
    path: /path/to/shashi_dir
    dest: /path/to/shashi.tgz
 
ii) Create a Archive File and Remove.
- name: Compress regular file /path/to/shashi into /path/to/foo.gz and remove it
  archive:
    path: /path/to/shashi
    dest: /path/to/shashi.tgz
    remove: yes
 
iii) Create a Archive File.
- name: Create a bz2 archive of /path/to/shashi
  archive:
    path: /path/to/shashi
    format: bz2
 
6. Git Module.
---
- hosts: localhost
gather_facts: no
vars:
username: decodingdevops
token: d6sdfshhghyjggj448t8tnt9h
repo_name: devops
 
tasks:
- name: Checkout The Code From Github Using Ansible.
git:
repo: 'https://{{ token }}@github.com/{{ username }}/{{ repo_name }}.git'
dest: /root/mycode
 
7. Command Module.

i) cat command.
- name: Executing a command using the command module
  command: cat helloworld.txt
 
ii) Check Uptime of Remote Linux.
---
 - name: Check the remote host uptime
    hosts: servers
    tasks:
      - name: Execute the Uptime command over Command module
        register: uptimeoutput
        command: "uptime"
 
- debug:
          var: uptimeoutput.stdout_lines
 
8.Variables to Retrieve the Results of Running Commands.

i) Check Disk Space
---
 - hosts: all
   become: yes
 
   tasks:
     - name: Execute /boot usage on Hosts
       command: 'df -Th /'
       register: df
     - debug: var=df.stdout