Control Node:
A system on which Ansible is installed. You run Ansible commands such as ansible or ansible-inventory on a control node.
Inventory
A list of managed nodes that are logically organized. You create an inventory on the control node to describe host deployments to Ansible.
Managed node
A remote system, or host, that Ansible controls.
What is Ansible and why this is so important?
Ansible is used for the multi-tier deployments and it models all of IT infrastructure into one deployment instead of handling each one separately. There are no agents and no custom security architecture is required to be used in the Ansible architecture. The deployment is simple plain English like language that is used in Ansible called YAML which stands for “YAML Ain’t Markup Language.”
To work with Ansible is very easy; it pushes out small programs called “Ansible Modules” to your nodes to connect. It can deploy and connect using the SSH agent to execute the modules and then removes it when finished.
There are no servers, daemons or databases required these modules can reside anywhere in the machines. You need to work with any text editor or terminal programs and along with a version control system to manage the changes in the content.
What is main Components of Ansible Architecture?
Ansible is a radically simple IT automation engine that automates cloud provisioning, configuration management, application deployment, intra-service orchestration, and many other IT needs. Being designed for multi-tier deployments since day one, Ansible models your IT infrastructure by describing how all of your systems inter-relate, rather than just managing one system at a time. It uses no agents and no additional custom security infrastructure, so it is easy to deploy - and most importantly, it uses a very simple language (YAML, in the form of Ansible Playbooks) that allows you to describe your automation jobs in a way that approaches plain English.
Web-Server Configuration ansible-playbook
ansible@cn ~$ vim web-server.yml
---
- name: Configuring web server
hosts: all
tasks:
- name: "Yum repository configuration on node1 machine"
ansible.builtin.yum_repository:
name: "{{ item.name }}"
description: YUM repo
file: external
baseurl: "{{ item.baseurl }}"
gpgcheck: 0
enabled: 1
loop:
- { name: online_one, baseurl: "https://mirror.stream.centos.org/9-stream/AppStream/x86_64/os/" }
- { name: online_two, baseurl: "https://mirror.stream.centos.org/9-stream/BaseOS/x86_64/os/" }
when: ansible_facts.distribution in ['RedHat','Fedora'] and ansible_facts.distribution_major_version | int >= 9
- name: Install yum package
yum:
name: httpd
state: latest
notify: restart service
- name: create index.html
file:
path: /var/www/html/index.html
state: touch
- name: 'add 80 port in firewall'
firewalld:
port: 80/tcp
state: enabled
immediate: true
permanent: true
- name: add some lines
lineinfile:
line: "This is web-server successful deployment"
path: /var/www/html/index.html
handlers:
- name: restart service
service:
name: httpd
state: restarted
enabled: yes
$ ansible-playbook web-server.yml
User configuration Setup for Password-less SSH and sudo Permissions using Ansible playbook.
localhost@ansible ~$ vim webserver.yml
---
- name: Configuring task1
hosts: all
vars:
username: shyam
userpass: password
tasks:
- name: Create a new user "{{ username }}"
user:
name: "{{ username }}"
password: "{{ userpass | password_hash('sha512') }}"
state: present
- name: Configure ssh to make password-less connection between managed-hosts machines
ansible.posix.authorized_key:
user: '{{ username }}'
state: present
key: "{{ lookup('file', '/home/ansible/.ssh/id_rsa.pub') }}"
- name: Provide sudoers permission to user '{{ username }}'
ansible.builtin.file:
path: /etc/sudoers.d/{{ username }}
state: touch
- name: sudoers entry in /etc/sudoers.d/{{ username }}
ansible.builtin.lineinfile:
path: /etc/sudoers.d/{{ username }}
line: "'{{ username }}' ALL=(ALL) NOPASSWD:ALL"
- name: restart sshd service
ansible.builtin.service:
name: sshd
state: restarted
$ ansible-playbook basic-task1.yml
Normal Linux Admin Tasks Automation By Ansible
$ vim basic.yml
---
- name: Solve RHCSA practice dump paper question
hosts: stage
gather_facts: true
vars:
- userpass: aternoth
tasks:
- name: "Yum repository configuration on node1 machine"
ansible.builtin.yum_repository:
name: "{{ item.name }}"
description: YUM repo
file: external
baseurl: "{{ item.baseurl }}"
gpgcheck: 0
enabled: 1
loop:
- { name: online_one, baseurl: "https://mirror.stream.centos.org/9-stream/AppStream/x86_64/os/" }
- { name: online_two, baseurl: "https://mirror.stream.centos.org/9-stream/BaseOS/x86_64/os/" }
when: ansible_facts.distribution == "RedHat" or ansible_facts.distribution == "Fedora"
- name: "Install httpd package"
yum:
name: "{{ item }}"
state: latest
loop:
- firewalld
- httpd
- selinux-policy
- name: "Start the services"
service:
name: "{{ item }}"
state: started
enabled: true
loop:
- httpd
- firewalld
- name: "add 82 port on selinux"
community.general.seport:
ports: 82
proto: tcp
setype: http_port_t
state: present
- name: add port 82 on firewall
ansible.posix.firewalld:
port: 82/tcp
permanent: true
state: enabled
immediate: yes
- name: Ensure the default Apache port is 82
ansible.builtin.lineinfile:
path: /etc/httpd/conf/httpd.conf
regexp: '^Listen '
line: Listen 82
- name: Check if user natasha exists
ansible.builtin.command: getent passwd natasha
register: natasha_user_check
ignore_errors: true
- name: create a user natasha is not exists
user:
name: natasha
state: present
when: natasha_user_check.rc != 0
- name: cronjob
ansible.builtin.cron:
name: "check dirs"
minute: "30"
hour: "13"
user: natasha
job: "/bin/echo hiya"
- name: restart crond service
service:
name: crond
state: restarted
enabled: true
- name: create group sysadmin
group:
name: sysadmin
state: present
- name: "Create the following users, groups, and group memberships"
user:
name: "{{ item.name }}"
state: present
groups: "{{ item.group }}"
password: "{{ userpass | password_hash('sha512') }}"
shell: "{{ item.shell }}"
loop:
- { name: natasha, group: sysadmin, shell: /bin/bash }
- { name: sarah, group: sysadmin, shell: /bin/bash }
- name: "Create user harry with no login shell"
user:
name: harry
password: "{{ userpass | password_hash('sha512') }}"
shell: /sbin/nologin
- name: "Create a collaborative directory “/common/admin” and do following conf"
file:
path: /common/admin #--------- /common directory should be created on managed host
group: sysadmin
state: directory
mode: 02770
ansible-playbook basic.yml
How to create disk Logical Volume partition, and mount
[ansible@cn ~]$ vim partition.yml
- name: playbook for simple 1 GB partition
hosts: stage
become: true
tasks:
- name: create partition
parted:
device: /dev/sdc
number: 1
flags: [ lvm ]
state: present
part_end: 4GB
register: opt
- name: Show details
debug:
var: opt
- name: Install lvm2 dependency
package:
name: lvm2
state: present
- name: task for creating volume group
lvg:
vg: sample-vg2
pvs: /dev/sdc
pesize: 16
- name: task for creating logical volume
lvol:
vg: sample-vg2
lv: sample-lv2
size: 1g
force: yes
- name: Create directory data1 if does not exist
file:
path: /data3
state: directory
mode: '0755'
- name: format the xfs filesystem
filesystem:
fstype: xfs
dev: /dev/sample-vg2/sample-lv2
- name: mount the lv on /data3
mount:
path: /data3
src: /dev/sample-vg2/sample-lv2
fstype: xfs
state: mounted
$ ansible-playbook partition.yml
