📍ANSIBLE day-03

ANSIBLE ADHOC-COMMANDS

some basic commands are:

📌It will ping all the servers which you have mentioned in inventory file(/etc/ansible/hosts)

ansible all -m ping

📌It will display the output in single line

ansible all -m ping -o

ansible all -m shell -a 'date'

📌To check the Date

📌To check the OS version

ansible all -m shell -a ' cat /etc/*release* '

📌 To check the service sshd status

ansible all -m shell -a ' service sshd status'

📌 To check the git version

ansible all -m shell -a 'git --version'

git not installed.

📌To install git in slave machine

ansible all -m shell -a 'sudo yum install -y git-all'

📌To install the httpd package in latest version

ansible all -m yum -a 'sudo yum install httpd -y'

📌Q: Irrespective of underlying os which module we can use to manage packages(softwares) using package manager in ansible?

A: Ansible introduced “package manager “ to work with underlying package manager

📌WHAT IS YAML?

✅The full form of yaml is yet another markup language.

✅This yaml file is both human readable and machine-readable format.

✅The extension of yaml is in .yml

✅The official website is — https://yaml.org/

✅ Let us see how to write yml file –

✅The yml file starts with — — and ends with — -

✅Between these — — we can write our requirements and the requirements should be entered in key value pair

📌WHAT IS PLAYBOOK:

✅Playbook are single yaml file that contains one or more plays in the list.

✅Here the plays represent set of tasks to be performed when the playbook executed.

✅ The task can be –

🚀Executing a command

🚀Executing a script

🚀Install the package

🚀Remove the package

🚀Updating the existing package.

✅The playbook contains the following sections:

✅Starting and ending section ( — -) and ( — -)

✅Second the host section [ on which host or slave we need to run this task]

✅ Third variable section [ we can define the set of variables to define in yml file]

✅Task section — this section lists out the all the task to be executed on the target host machine. It specifies the list of modules.

📌Sample yml file to ping all host servers:

📌demo.yml

---
- hosts: all
  tasks:
    - name: Ping All Host Nodes
      ping:
      remote_user: ansible

how can we know that our written syntax is correct? There is one way we can let ansible to check by using the command — ansible-playbook <filename> — syntax-check

📌Then we can execute the command by using — ansible-playbook <filename>

ansible-playbook ping.yml

📌We can able to ping the slave server. If we want to know more details we can do one more command — ansible-playbook ping.yml -vv

ansible-playbook ping.yml -vv

📌Again, if we want to full details, we need to increase one more command — ansible-playbook ping.yml -vvv

ansible-playbook ping.yml -vvv

📌It will provide help on ansible-playbook command

ansible-playbook --help

📌It will check the syntax of a playbook

ansible-playbook ping.yml --syntax-check

📌It will do in dry run

ansible-playbook ping.yml --check

📌It will display the which hosts would be effected by a playbook before run

ansible-playbook ping.yml --list-hosts

📌It execute one step-at-a-time, confirm each task before running with (N)o/(Y)es/(c)ontinue

ansible-playbook ping.yml --step

📌Create a playbook called create file.yml

- hosts: all
  tasks:
    - name: Create file in all host nodes
      file:
        path: /home/ec2-user/hello.txt
        state: touch

📌created file in ‘slave machine’

📌copy the content into the created file

- hosts: all
  tasks:
    - name: Copy the content into the file
      copy: content="welcome swetha!"dest="/home/ec2-user/hello.txt"

vi httpd.yml

📌To install httpd package in all host nodes

# write a playbook to install httpd package in all host nodes
- hosts: all
  become: true
  tasks:
    - name: install httpd package
      yum:
        name: httpd
        state: latest

vi httpdstart.yml

📌To start the httpd server in all host nodes

# write a playbook to start httpd server in all host nodes
- hosts: all
  become: true
  tasks:
    - name: install httpd package
      yum:
        name: httpd
        state: latest
    - name: start httpd server
      service:
        name: httpd
        state: started

📌To copy the public ip address and paste the browser

📌write a playbook to install httpd, copy index.html and start the httpd server

- hosts: all
  become: true
  tasks:
    - name: install httpd package
      yum:
        name: httpd
        state: latest
    - name: copy index.html file
      copy:
        src: index.html
        dest: /var/www/html/index.html
    - name: start httpd service
      service: 
        name: httpd
        state: started

📌create one file called index.html in master machine

<h1>Heyyyyyyy swetha!</h1>

📌To copy the public ip address and paste the browser