---
-name: webserver
 host:web
 vars_files:
   - var-file.yml

 tasks:
 -name: Install latest httpd
  yum:
     name: "{{packname}}"
     state: latest
 - name: Start service httpd, if not started
   ansible.builtin.service:
      name: "{{packname}}"
      state: started

Assigment 2 – Create a playbook and setup a webserver(httpd) and use httpd as a variable declared using prompt.

---
-name: webserver
 host: web
 vars_prompt:
   - name: "webserver"
      prompt: "Which webserver do you want to install?"
      private: false
 tasks:
 - yum:
    name: "{{ webserver }}"
    state: latest
 - name: Start service httpd, if not started
    ansible.builtin.service:
      name: "{{ webserver }}"
      state: started

Assigment 3 – Create a playbook and setup a webserver(httpd) and find a list of .txt file in some directory and output using register variables

---
-name: webserver
 host:web
 vars:
   webserver: httpd

 tasks:
 -name: Install latest httpd
  yum:
    name: "{{ webserver }}"
    state: latest
 - name: Start service httpd, if not started
    ansible.builtin.service:
      name: "{{ webserver }}"
      state: started
 -name: Listing .txt files
    shell: "find *.txt"
    args:
      chdir: "/home/centos/ansible/sanchita"
    register: find_output
 - name: Print the vars
   ansible.builtin.debug:
     var: find_output.stdout_lines
    

Assigment 4 – Create a playbook and setup a webserver(httpd), copy a index.html and interpolate variables in template file decalared in playbook.

---
-name: webserver
 host:web
 vars:
   webserver: httpd
 
 tasks:
 -name: Install latest httpd
  yum:
    name: "{{ webserver }}"
    state: latest
 - name: copy index.html
   ansible.builtin.template:
     src: index.html.j2
     dest: /var/www/html/
 - name: Start service httpd, if not started
   ansible.builtin.service:
     name: "{{ webserver }}"
     state: started

---
- name: Assignment 2
  hosts: localhost
  vars:
    webserver: httpd

  tasks:
  - name: Install the latest version of webserver
    yum:
      name={{ webserver}}
      state=latest
    when: ansible_os_family == "RedHat"
  - name: Install the latest version of webserver
    apt:
      name={{ webserver}}
      state=latest
    when: ansible_os_family == "Ubuntu"
  - name: Install the latest version of webserver
    apt:
      name={{ webserver}}
      state=latest
    when: ansible_os_family == "Ubuntu"
  - name: Return motd to registered var
    ansible.builtin.command: ls /etc
    register: find_output
  - debug:
      msg: "The list in directory /etc is" {{ find_output.stdout_lines }}

There are 2 environment DEV and QA. Both has their own group_vars. Using it, in Dev and QA environment(RHEL/CENTOS) install apache and Dev should run with 80 port and QA should run with 8080 port. Whereas config file locaton for apache conf is /etc/httpd.conf/conf/httpd.conf and line for port is “Listen 80”. This should be done using template module and zinja2 lib.

#group_vars/dev
port: 80

#group_vars/qa
port: 8080

---
- name: Template module and zinza2 module
  hosts: dev,qa

  tasks:
  - name: Install latest httpd
    yum:
      name: httpd
      state: latest
  - name: Template a file to /etc/file.conf
    ansible.builtin.template:
      src: httpd.conf.j2
      dest: /etc/httpd/conf/httpd.conf
    notify:
      - Start service httpd, if not started
  - name: Start service httpd, if not started
    ansible.builtin.service:
      name=httpd
      state=started

  - debug: 
      msg: Port {{ port }}
  handlers:
  - name: Start service httpd, if not started
    ansible.builtin.service:
      name=httpd
      state=restarted

Write a 3 yaml playbook i.e main.yaml, second.yaml and third.yaml with some demo debug tasks and call second.yaml and third.yaml from main.yaml using include.

# second.yaml
- name: Debug
  debug:
    msg: In second.yaml

# third.yaml
- name: Debug
  debug:
    msg: In third.yaml

#main.yaml
- hosts: all
  tasks:
    - debug:
        msg: task1

- include: second.yaml
- include: third.yaml

# inventory
[web]
13.232.181.124
35.154.128.2

[web:vars]
ansible_user=centos
ansible_ssh_private_key_file=node.pem
ansible_become=yes

#assignment.yaml
- name: Playbook Assignment
  hosts: web

  tasks:
  - name: Create group called deploy
    group:
      name: Deploy
      state: present
  - name: Create user in group with bin bash shell
    user:
      name: deploy-user
      shell=/bin/bash
      state: present
  - name: Install the latest version of Apache
    yum:
      name: httpd
      state: latest
  - name: Create file second in var/www/html
    file:
      path: /var/www/html/second.html
      state: file
  - name: Copy file with owner and permissions
    ansible.builtin.copy:
      src: index.html
      dest: /var/www/html/index.html
  - name: Start service httpd, if not started
    ansible.builtin.service:
      name: httpd
      state: started
  - name: Install the latest version of git and wget
    yum:
      name: git
      state: latest
    yum:
      name: wget
      state: latest

- name: Playbook Assignment
  hosts: localhost

  tasks:
  - name: Clone repository
    git:
      repo: 'https://github.com/scmgalaxy/ansible-role-template
      dest = /home/centos/ansible/sanchita
      clone: yes
  - name: Start service httpd, if not started
    reboot:

To run the playbook:

$ ansible-playbook -i inventory assignment.yaml

Playbook Variables

# playbook-variables.yaml
---
- name: Variable precedence
  hosts: localhost
  vars:
    myname: Sanchita
  vars_prompt:
    - name: "myname"
      prompt: "What is your name?"
      private: false
  vars_files:
    - ext-vars.yaml

  tasks:
  - name: Print the vars
    ansible.builtin.debug:
      msg: My name {{ myname }}
  - name: include default step variables
    include_vars: var-include.yaml
  - name: Print the vars
    ansible.builtin.debug:
      msg: My name {{ myname }}
  - name: Ansible register variable basic example
    shell: "find *.yaml"
    args:
      chdir: "/home/centos/ansible/sanchita"
    register: find_output
  - debug:
      var: find_output.stdout_lines[0]
  - name: Print the vars
    ansible.builtin.debug:
      msg: My name is  {{ myname }}

Precedence of Variables

• Command Line variable takes precedence over all other.
• Variables using task include takes precedence over all, except command line variable.
• External variables take precedence over variable prompt.
• Variable using prompt takes precedence over embedded variables.

$ ansible localhost -m group -a”name=deploy state=present” -b

Write a Ansible Adhoc Commands to create a user called “deploy-user” which is part of group called “deploy” and with /bin/bash shell.

$ ansible localhost -m user -a “name=deploy-user group=deploy shell=/bin/bash state=present” -b

 Write a Ansible Adhoc commands install package named “httpd” in RHEL/centos.

ansible localhost -m yum -a”state=present name=httpd” -b

Write a Ansible Adhoc commands to start and enable the service named “httpd”

$ ansible localhost -m service -a”name=httpd state=started” -b

Write a Ansible commands to copy a file called “second.html” in /var/www/html/second.html with some dummy html contents.

$ ansible localhost -m copy -a”dest=/var/www/html src=second.html” -b

Ansible is a cross-platform Configuration Management Tool for Server(s), which is primarily written using python.

Benefits of Ansible

The benefits are as follows:

• It is easy to learn, understand and use which makes it the choice for server config management
• It is Idempotent, that is, there are no additional effect if it is called more than once with the same input parameters.
• It is Platform Independent.
• Ansible-Command prompt is free.

Architecture of Ansible