Sample OS Patching Ansible Yaml Code

 Sample OS Patching Ansible Yaml Code:

=======================================

---
- name: OS patching of Webservers
  hosts: webservers
  serial: 2
  become: true
  tasks:
    - name : Stop Httpd Service
      service:
        name: httpd
        state: stopped
      when: ansible_distribution == 'CentOS'
    - name : Stop Apache2 Service
      service:
        name: apache2
        state: stopped
      when: ansible_distribution == 'Ubuntu'
    - name : Stop Tomcat Service
      service:
        name: tomcat
        state: stopped
    - name : Stop Keycloak Service
      service:
        name: keycloak
        state: stopped
    - name:  Verify  processes are not running
      shell: if ps -eaf | egrep 'apache|http|tomcat|keycloak'|grep -v grep > /dev/null ;then echo 'process_running';else echo 'process_not_running';fi
      ignore_errors: true
      register: result_process_check
    - name: Run Backup Script prior OS patch
      shell:  sh /opt/scripts/backup_prior_os_patch.sh
    - name: Centos OS paching
      yum:
        name: '*'
        state: latest
      when: result_process_check.stdout == "process_not_running" and ansible_os_family == "RedHat"
    - name: Update Ubuntu repositories cache
      apt:
        update_cache: yes
      when: result_process_check.stdout == "process_not_running" and ansible_os_family == "Debian"
    - name: Update all packages to their latest version
      apt:
        name: "*"
        state: latest
      when: ansible_os_family == "Debian"
    - name: Upgrade the OS (apt-get dist-upgrade)
      apt:
        upgrade: dist
      when: ansible_os_family == "Debian"
    - name: Rebooting the servers
      reboot:
        msg: "Rebooting  Servers After Kernel Patching"
        connect_timeout: 5
        reboot_timeout: 300
        pre_reboot_delay: 0
        post_reboot_delay: 30
        test_command: uptime
      ignore_errors: true

    - name: pause for 180 secs
      pause:
        minutes: 3

Some Usable Adhoc commands

 Some Usable Adhoc commands:

================================

Creating a file on all remote clients

# ansible all –m file –a “path=/home/vishnu/vishnu1 state=touch mode=700”

Deleting a file on all remote clients

# ansible all –m file –a “path=/home/vishnu/vishnu1 state=absent”

Copying a file to remote clients

# ansible all –m copy –a “src=/tmp/vishnu2 dest=/home/vishnu/vishnu2”

Installing package (telnet and httpd-manual)

# ansible all –m yum –a “name=telnet state=present”

# ansible all –m yum –a “name=httpd-manual state=present”. 

Starting httpd package service

# ansible all –m service –a “name=httpd state=started”

Start httpd and enable at boot time

# ansible all –m service –a “name=httpd state=started enabled=yes”

Checking httpd service status on remote client

# ansible all –m shell -a “systemctl status httpd”

Remove httpd package

# ansible all –m yum –a “name=httpd state=absent”

OR

# ansible all –m shell -a “yum remove httpd”.

Creating a user on remote clients

# ansible all –m user –a “name=appu home=/home/appu shell=/bin/bash state=present”

To add a user to a different group

# ansible all –m user –a “name=appu group=vishnu”

Deleting a user on remote clients

# ansible all –m user –a “name=appu home=/home/appu shell=/bin/bash state=absent”

OR

# ansible all –m shell –a “userdel appu”

Getting system information from remote clients

# ansible all –m setup

You can run commands on the remote host without a shell module e.g. reboot client1

# ansible client1 –a “/sbin/reboot”

Mysql server Installation

 

Mysql server Installation:

- name: Install Mysql server, Create database with remote login
  become: yes
  hosts: localhost
  vars:
    Mysql_DB: mysqldb
    Mysql_User: mysql_user
    Mysql_Pass: Password
  tasks:
    - name: Mysql Installation
      package:
        name: "{{item}}"
        state: present
        update_cache: yes
      loop:
        - mysql-server
        - mysql-client
        - python3-mysqldb
        - libmysqlclient-dev
      become: yes

    - name: start and enable mysql service
      service:
        name: mysql
        state: started
        enabled: yes

    - name: create  the user
      mysql_user:
        name: "{{ Mysql_User }}"
        password: "{{ Mysql_Pass }}"
        priv: '*.*:ALL'
        host: '%'
        state: present

    - name: creating the database
      mysql_db:
        name: "{{ Mysql_DB }}"
        state: present

    - name: Enable remote login to mysql
      lineinfile:
         path: /etc/mysql/mysql.conf.d/mysqld.cnf
         regexp: '^bind-address'
         line: 'bind-address = 0.0.0.0'
         backup: yes
      notify:
         - Restart mysql
  handlers:
    - name: Restart mysql
      service:
        name: mysql
        state: restarted

Some Examples of File Module

 Some Examples of File Module:

---
- name: Check if the file or Direcory exists
  hosts: localhost
  become: true
  any_errors_fatal: true
  vars:
    directory: "/tmp"

  tasks:
    - name: Check the status
      stat:
        path: "{{directory}}"
      register: result

    - name: Directory Status
      debug:
        msg: "Directory {{directory}} present"
      when: result.stat.isdir is defined and result.stat.isdir

====================================================================================

---
- name: Check if the file exists
  hosts: localhost
  vars:
    file_path: "/tmp/test"
  become: true
  tasks:
    - name:  Check the file status
      stat:
        path: "{{file_path}}"
      register: result
    - name:  File Exists
      debug:
        msg: "File Exists"
      when: result.stat.exists
    - name: File don't Exists
      debug:
        msg: "File don't exists"
      when: not result.stat.exists

====================================================================================

---
- name: File Ownership
  hosts: localhost
  vars:
    file_name: "/tmp/a"
  become: true
  tasks:
    - name: Change ownership of file
      file:
        path: "{{file_name}}"
        owner: vishnu
        group: vishnu
        mode: 0777


=================================================================================

---
- name: Create Symbolic link
  hosts: localhost
  become: true
  vars:
    sym_link: "/tmp/test1"
    source: "/tmp/test"
  tasks:
    - name: Symbolic link creation
      file:
        src: "{{source}}"
        dest: "{{sym_link}}"
        state: link

==================================================================================


---
- name: Hard Link
  hosts: localhost
  become: true
  vars:
    source: "/tmp/a"
    destin: "/tmp/b"
  tasks:
    - name: "Hard Link"
      file:
        src: "{{source}}"
        dest: "{{destin}}"
        state: hard

=================================================================================

Install Apache on Centos Servers:

 Install Apache on Centos Servers:

---
- name: Install httpd and start the service
  hosts: localhost
  become: true
  tasks:
    - name: install http
      yum:
        name: httpd
        state: latest
    - name: Copy the configuration file
      file:
        src: /tmp/httpd.conf
        dest: /etc/httpd/httpd.conf
      notify:
        Restart Apache
    - name: Start Apache service
      service:
        name: httpd
        state: started
        enabled: true
  handlers:
    - name: Restart Apache
      service:
        name: httpd
        state: restarted

Basic Postgresql Installtion as a Single Node

 Basic Postgresql Installtion as a Single Node:

---
- name: Install postgres
  hosts: localhost
  become: true
  tasks:
    - name: Install postgres
      yum:
        name:
          - postgresql
          - postgresql-server
          - postgresql-contrib
          - postgresql-libs
          - python3-psycopg2
        state: present

    - name: Postgresql initialized or not
      stat:
        path: /var/lib/pgsql/data/pg_hba.conf
      register: result

    - name: InitDB
      shell: postgresql-setup initdb
      when: not result.stat.exists


    - name: Open port for postgresql
      firewalld:
        service: postgresql
        permanent: true
        state: enabled
      notify:
        - Reload firewalld

    - name : Start service
      service: postgresql
      state: started
      enabled: true

  handlers:
    - name: Reload firewalld
      service: firewalld
      state: reloaded

Postgresql Database Dump and restore Using Ansible

 Postgresql Database Dump and restore Using Ansible

---
- name: Take the backup
  hosts: localhost
  tasks:
    - name: DB backup
      postgresql_db:
        name: postgres
        state: dump
        target: /backup/postgresql.sql.gz



================================================================
---
- name: Restore from Dump
  hosts: db1
  tasks:
    - name: Restore DB
      postgresl_db:
        name: db1
        state: restore
        target: /tmp/backup.sql.gz
      become: true
      become_user: postgres

Ansible code to update /etc/hosts on remote servers.

 Ansible code to update /etc/hosts on remote servers.

# Update host file
---
- name: Update host file
  hosts: localhost
  become: true
  tasks:
  - name: Generate /etc/hosts file
    blockinfile:
      state: present
      dest: /etc/hosts1
      content: |
        10.1.1.1 demo demo0.linuxgeeknotes.com
        10.0.0.0 demo1 demo1.linuxgeeknotes.com
        10.2.2.2 demo2 demo2.linuxgeeknotes.com

NFS Server Configuration in Ubuntu using Ansible

 Configure NFS Server
==================

---
- name : NFS Server Installation and  Configuration
  hosts: localhost
  become: yes
  vars:
    - share : "/linuxgeeknotes/share/"
    - fstab_entry: "10.5.0.0/24(rw,sync,root_squash)"
  tasks:
    - name: Install NFS Server
      apt:
        name: nfs-kernel-server
        state: present
    - name: Create Share Directory
      file:
        path: {{share}}
        state: directory
        mode: 0777
        user: linuxgeeknotes
        group: linuxgeeknotes
    - name: Updating the export file
      lineinfile:
        path: /etc/exports
        state: present
        line: "{{share}} {{fstab_entry}}"
      notify: Restart NFS Server

    - name: Run Exportfs
      command: "exportfs -a"

    - name: Open Firewall for NFS Service
      ufw:
        service: {{item}}
        state: enabled
        permanent: true
        immediate: true
      with_items:
        - nfs
        - mountd
  handlers:
    - name: Restart NFS Server
      service:
        name: nfs-kernel-server
        state: restarted
        enabled: true