Ansible Roles
Ansible roles are helpful in defining framework for vars_files, handlers and tasks with support of best-known file structure. Roles are grouped to allow easy sharing of roles with other users.This simplifies writing complex playbooks, and it makes them easier to reuse. A playbook can be splitted into reusable components.
Creating a New Role
ANSIBLE GALAXY
A Galaxy website is referred by ansible galaxy (community) for sharing roles and roles can be shared to command-line tool for installation, creation and management of roles. We can use Galaxy’s Search page to find Roles and Collections for your project, then follow the instructions to download them onto your Ansible host.The Ansible Galaxy program line tool comes full of Ansible, and it will be accustomed install roles from Galaxy or directly from a supply management Management system like Git”.
Role Structure
Roles have a quite structured layout on the file system. We can change the default structure but for learning purposes let’s go with the default one for better understanding.
The role name is the directory name within yours /roles directory.
$ ansible-galaxy -h
Usage
ansible-galaxy [delete|import|info|init|install|list|login|remove|search|setup] [--help] [options] ...
Options
-h, --help − Show this help message and exit.
-v, --verbose − Verbose mode (-vvv for more, -vvvv to enable connection debugging)
--version − Show program's version number and exit.
Creating a Role Directory
The below command has created the role directories.
$ ansible-galaxy init salesforcedrillers
ERROR! The API server (https://galaxy.ansible.com/api/) is not responding, please try again later.
$ ansible-galaxy init --force --offline salesforcedrillers
- salesforcedrillers was created successfully
$ tree salesforcedrillers/
salesforcedrillers/
├── defaults
│ └── main.yml
├── files ├── handlers
│ └── main.yml
├── meta
│ └── main.yml
├── README.md ├── tasks
│ └── main.yml
├── templates ├── tests │ ├── inventory
│ └── test.yml
└── vars
└── main.yml
8 directories, 8 files
Utilizing Roles in Playbook
This is the code of the playbook we have written for this demo purpose. This code is of the playbook salesforcedrillers_orchestrate.yml. We have defined the hosts: jenkins and called the role – install-jenkins
The problem statement is that we have a war file which we need to deploy on a machine via Ansible.
---
- hosts: jenkins
roles:
- {role: install-jenkins}
Install Jenkins Using Ansible
1.Create PlayBook
# cat site.yml
---
- name: Install Jenkins
hosts: jenkins
gather_facts: false
become: true
tasks:
- import_role:
name: jenkins
2. Create a role
# cat roles/jenkins/tasks/main.yml
---
- name: install wget
yum:
name: wget
state: present
- name: install openjdk
yum:
name: java-1.8.0-openjdk
state: present
- name: download jenkins.repo
get_url:
url: http://pkg.jenkins-ci.org/redhat-stable/jenkins.repo
dest: /etc/yum.repos.d/jenkins.repo
- name: import jenkins key
rpm_key:
state: present
key: https://jenkins-ci.org/redhat/jenkins-ci.org.key
- name: install jenkins
yum:
name: jenkins
state: present
- name: start jenkins
systemd:
name: jenkins
state: started
- name: enable jenkins
systemd:
name: jenkins
enabled: true
- name: sleep for 30 seconds and continue with play
wait_for: timeout=30
delegate_to: localhost
- name: init password jenkin
shell: cat /var/lib/jenkins/secrets/initialAdminPassword
changed_when: false
register: result
- name: print init password jenkins
debug:
var: result.stdout
BUILDING JENKINS
1. Build Jenkins from Ansible server
# ansible-playbook -i inventory/hosts site.yml
PLAY [Install Jenkins] *********************************************
changed: [172.31.40.119]
TASK [jenkins : install openjdk] ******************************************
changed: [172.31.40.119]
TASK [jenkins : download jenkins.repo] ************************************
changed: [172.31.40.119]
TASK [jenkins : import jenkins key] ***************************************
changed: [172.31.40.119]
TASK [jenkins : install jenkins] ******************************************
changed: [172.31.40.119]
TASK [jenkins : start jenkins] ********************************************
changed: [172.31.40.119]
TASK [jenkins : enable jenkins] *******************************************
ok: [172.31.40.119]
TASK [jenkins : sleep for 30 seconds and continue with play] **************
ok: [172.31.40.119 -> localhost]
TASK [jenkins : init password jenkin] *************************************
ok: [172.31.40.119]
TASK [jenkins : print init password jenkins] ******************************
ok: [172.31.40.119] => {
"result.stdout": "145a4427b9b94afdacbe724d7db6bd2c"
}
PLAY RECAP ****************************************************************
172.31.40.119 : ok=10 changed=6 unreachable=0 failed=0
2. Please confirm the connection of Jenkins on the Web (specify the password of result.stdout)
Now proceed with the installation steps mentioned in jenkins installation tutorial in the Devops Section (https://salesforcedrillers.com/learn-devops/what-is-jenkins/ )