Introduction

I will explain the ansible roles directory structure. The confusing using roles are understanding the file hierarch. Ansible provides a feature called Ansible galaxy that helps you play roles.

For example, Ansible roles directory will look like as below:

[vagrant@ansible_controller demo]$ tree nodejs
nodejs
├── 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

You can be using ansible galaxy it creates a role.

$ sudo ansible-galaxy init <role-name>
# Example init nodejs role
$ sudo ansible-galaxy init nodejs

Explain Ansible directories

• Tasks: The main list of tasks to be exectued by role. it contains the main.yml file.
• Files: Contains files that can be deployed by this role
• Handlers: Contains handlers which may be used by this role or even anywhere outside this role.
• Defaults: Contains the default variables used by this role.
• Vars: This directory consists of other variables that used by the roles. These variables can be defined in ansible playbook.
• Meta: Defines metadata for this role. it contains file role dependencies.

Demo Using Ansible install nodejs

I use ansible-galaxy to download template nodejs role as command below:

[vagrant@ansible_controller demo]$ ansible-galaxy init nodejs

My Ansible structure folder and file as below:

[vagrant@ansible_controller ~]$ tree demo
demo
├── ansible.cfg
├── install-nodejs.yml
├── inventory
│   └── hosts
└── roles
    └── nodejs
        ├── defaults
        │   └── main.yml
        ├── files
        ├── handlers
        │   └── main.yml
        ├── meta
        │   └── main.yml
        ├── README.md
        ├── tasks
        │   └── main.yml
        ├── templates
        └── vars
            └── main.yml

10 directories, 9 files

Write roles/nodejs/tasks/main.yml for nodejs role as below:

---
# Example, tasks file for nodejs
- name: Node.js - Get script
  get_url:
    url: "https://rpm.nodesource.com/setup_10.x"
    dest: "{{ var_node }}/nodejs.sh"

- name: Node.js - Set execution permission to script
  file:
    path: "{{ var_node }}/nodejs.sh"
    mode: "u+x"

- name: Node.js - Execute installation script
  shell: "{{ var_node }}/nodejs.sh"

- name: Node.js - Remove installation script
  file:
    path: "{{ var_node}}/nodejs.sh"
    state: absent

- name: Node.js - Install Node.js
  yum: name={{ item }} state=present update_cache=yes
  with_items:
    - epel-release
    - nodejs

- name: Node.js - Install bower and gulp globally
  npm: name={{ item }} state=present global=yes
  with_items:
    - bower
    - gulp

# check version
- name: "Check if nodejs is installed"
  package_facts:
    manager: "auto"
- name: "nodejs result"
  debug:
     msg: "nodejs found"
  when: "'nodejs' in ansible_facts.packages"
- name: "nodejs result"
  debug:
     msg: "nodejs NOT found"
  when: "'nodejs' not in ansible_facts.packages"

Write your main playbook. Example, install-nodejs.yml file.

---
- hosts: web-server
  become: yes
  vars:
    # variable needed during node installation
    var_node: /tmp
  roles:
       - nodejs

Ansible run command

[vagrant@ansible_controller demo]$ ansible-playbook -i inventory/hosts install-nodejs.yml

The result, install nodejs on the target server as below:

Conclusion

I hope will this your helpful. Thank you for reading the DevopsRoles page!

#Introduction

How to copy the template file to the remote server using Ansible. I use vagrant to create VMs. My example Ansible creates multiple servers here. In Ansible I use with_fileblob:

Ansible file and folder

[vagrant@ansible_controller ansible]$ tree .
.
├── ansible.cfg
├── copy-template.yml
├── hosts
└── roles
    └── copyfiles
        ├── tasks
        │   └── main.yml
        └── templates
            ├── devopsroles.conf.tmp
            ├── file1.conf.tmp
            └── file2.conf.tmp

4 directories, 7 files

Ansible copy template file to remote server script

copy-template.yml file.

---
- hosts: web-server
  become: yes
  roles:
       - copyfiles

Example: roles/copyfiles/tasks/main.yml file

---
- name: "Copy files template to remote server"
  template:
    src: "{{ item }}"
    dest: "/home/vagrant/dest/{{ item | basename | regex_replace('.tmp','') }}"
    owner: "root"
    group: "root"
    mode: 0644
  with_fileglob:
    - templates/*.tmp

Ansible run command 

[vagrant@ansible_controller ansible]$ ansible-playbook -i hosts copy-template.yml

The output terminal on the ansible controller

[vagrant@ansible_controller ansible]$ ansible-playbook -i hosts copy-template.yml
[WARNING]: Invalid characters were found in group names but not replaced, use -vvvv to see details

PLAY [web-server] ***************************************************************************************************

TASK [Gathering Facts] **********************************************************************************************
ok: [server1]

TASK [copyfiles : Copy files template to remote server] *************************************************************
changed: [server1] => (item=/home/vagrant/ansible/roles/copyfiles/templates/devopsroles.conf.tmp)
changed: [server1] => (item=/home/vagrant/ansible/roles/copyfiles/templates/file1.conf.tmp)
changed: [server1] => (item=/home/vagrant/ansible/roles/copyfiles/templates/file2.conf.tmp)

PLAY RECAP **********************************************************************************************************
server1                  : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

The result on remote server1.

[vagrant@server1 dest]$ pwd
/home/vagrant/dest
[vagrant@server1 dest]$ ll
total 12
-rw-r--r--. 1 root root 3 Jan 17 08:53 devopsroles.conf
-rw-r--r--. 1 root root 2 Jan 17 08:53 file1.conf
-rw-r--r--. 1 root root 2 Jan 17 08:53 file2.conf

Conclusion

You have to use Ansible copy template file to remote server. I hope will this your helpful. Thank you for reading the DevopsRoles page!

# Introduction

How to check for a package in the system using Ansible. I use vagrant to create VMs. My example Ansible creates multiple servers here. I will check the Apache package installed in Centos. Now, let’s go Ansible check package installed in Linux.

Ansible check package installed

Ansible file and folder

[vagrant@ansible_controller ~]$ tree .
.
├── ansible
│   ├── ansible.cfg
│   └── hosts
└── check-package.yml

We use the ansible module package_facts

Ansible script

---
- hosts: apache-server
  become: yes
  tasks:
    - name: "Check if APACHE is installed"
      package_facts:
        manager: "auto"
    - name: "Apache result"
      debug:
         msg: "Apache found"
      when: "'httpd' in ansible_facts.packages"
    - name: "Apache result"
      debug:
         msg: "Apache NOT found"
      when: "'httpd' not in ansible_facts.packages"

Ansible run command to check

[vagrant@ansible_controller ~]$ ansible-playbook -i ansible/hosts check-package.yml

The output terminal

[vagrant@ansible_controller ~]$ ansible-playbook -i ansible/hosts check-package.yml
[WARNING]: Invalid characters were found in group names but not replaced, use -vvvv to see details

PLAY [apache-server] ***************************************************************************************************************************************************************************************************************************

TASK [Gathering Facts] **********************************************************************************************************************************************************************************************************************
ok: [server1]

TASK [Check if APACHE is installed] *********************************************************************************************************************************************************************************************************
ok: [server1]

TASK [Apache result] ************************************************************************************************************************************************************************************************************************
ok: [server1] => {
    "msg": "Apache found"
}

TASK [Apache result] ************************************************************************************************************************************************************************************************************************
skipping: [server1]

PLAY RECAP **********************************************************************************************************************************************************************************************************************************
server1                  : ok=3    changed=0    unreachable=0    failed=0    skipped=1    rescued=0    ignored=0

I will remove the apache package on server1 apache.

[vagrant@server1 ~]$ sudo yum remove httpd -y

Ansible runs the command to check again:

[vagrant@ansible_controller ~]$ ansible-playbook -i ansible/hosts check-package.yml

The output terminal

[vagrant@ansible_controller ~]$ ansible-playbook -i ansible/hosts check-package.yml
[WARNING]: Invalid characters were found in group names but not replaced, use -vvvv to see details

PLAY [apache-server] ***************************************************************************************************************************************************************************************************************************

TASK [Gathering Facts] **********************************************************************************************************************************************************************************************************************
ok: [server1]

TASK [Check if APACHE is installed] *********************************************************************************************************************************************************************************************************
ok: [server1]

TASK [Apache result] ************************************************************************************************************************************************************************************************************************
skipping: [server1]

TASK [Apache result] ************************************************************************************************************************************************************************************************************************
ok: [server1] => {
    "msg": "Apache NOT found"
}

PLAY RECAP **********************************************************************************************************************************************************************************************************************************
server1                  : ok=3    changed=0    unreachable=0    failed=0    skipped=1    rescued=0    ignored=0

Conclusion

You have to use the Ansible check package installed in Linux. I hope will this your helpful. Thank you for reading the DevopsRoles page!

#Introduction

In this tutorial, How to set up an NFS server and client using Ansible. I use Vagrant. In my example, Ansible creates multiple servers here. Now, let’s go to the Ansible Setup NFS server and client.

Ansible file and folder

[vagrant@ansible_controller ~]$ tree .
.
├── ansible
│   ├── ansible.cfg
│   ├── exports.j2
│   └── hosts
├── nfs-client.yml
└── nfs-server.yml

1 directory, 5 files

Ansible script

nfs-server.yml file for NFS Server as below

---
- hosts: nfs-server
  become: yes
  tasks:
    - name: install nfs-utils
      yum: name=nfs-utils state=latest

    - name: Create a mountable directory if it does not exist
      file:
        path: /home/vagrant/nfs_test
        state: directory
        owner: vagrant
        group: vagrant
        mode: '0775'
    - name: enable rpcbind nfslock nfs
      service:
        name: "{{ item }}"
        enabled: yes
      with_items:
        - rpcbind
        - nfslock
        - nfs
    - name: Copy exports file.
      template:
        src: ./ansible/exports.j2
        dest: /etc/exports
        owner: root
        group: root
        mode: 0644
    - name: NFS apply change configrue
      shell: systemctl reload nfs;exportfs -a

nfs-client.yml file for nfs clients as below

---
- hosts: nfs-clients
  become: yes
  tasks:
    - name: install nfs-utils
      yum: name=nfs-utils state=latest

    - name: Create a mountable directory if it does not exist
      file:
        path: /mnt/web_storage
        state: directory
        owner: vagrant
        group: vagrant
        mode: '0775'
    - name: Mount volumn
      shell: sudo mount 192.168.3.9:/home/vagrant/nfs_test /mnt/web_storage

exports.j2 file with content as below

# /etc/exports: the access control list for filesystems which may be exported
#   to NFS clients.  See exports(5).
/mnt/nfs_test            *(rw,sync,no_root_squash,no_subtree_check)

My example hosts file as below

[nfs-server]
servernfs

[nfs-clients]
server1

File ansible/ansible.cfg example as below

[defaults]
inventory = ./hosts
forks = 15
log_path=$HOME/ansible/ansible.log
host_key_chcking = False
gathering = smart

Ansible run command for NFS server

[vagrant@ansible_controller ~]$ ansible-playbook -i ansible/hosts nfs-server.yml

The output terminal as picture below

Ansible run command for NFS client

[vagrant@ansible_controller ~]$ ansible-playbook -i ansible/hosts nfs-client.yml

The output terminal as picture below

Conclusion

You have to use ansible setup NFS server and NFS client. I hope will this your helpful. Thank you for reading the DevopsRoles page!

#Introduction

In this tutorial, How to use Ansible get IP address remote server. There are many methods to obtain the IP address the current of remote hosts. so let us learn how to use Ansible to get an IP address to remote hosts’ servers.

Structure file and folder Ansible get IP address remote server

[vagrant@ansible_controller ~]$ pwd
/home/vagrant
[vagrant@ansible_controller ~]$ tree .
.
├── ansible
│   ├── ansible.cfg
│   └── hosts
└── getIP.yml

1 directory, 3 files

Option 1: use hostvars

To retrieve the IP address of a remote server using Ansible, you can use the ansible_default_ipv4 variable. This variable provides information about the default IPv4 address of the target host.

For example the content file getIP.yml as below

[vagrant@ansible_controller ~]$ cat getIP.yml
---
- hosts: servers
  tasks:
  - name: Test hosts list
    debug:
      msg: "{{ hostvars[inventory_hostname]['ansible_default_ipv4']['address'] }}"

The output on terminal

[vagrant@ansible_controller ~]$ ansible-playbook getIP.yml -i .ansible/hosts

PLAY [servers] *********************************************************************************************************

TASK [Gathering Facts] *************************************************************************************************
ok: [server1]

TASK [Test hosts list] *************************************************************************************************
ok: [server1] => {
    "msg": "10.0.2.15"
}

PLAY RECAP *************************************************************************************************************
server1                    : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Here’s an example of how you can access the IP address:

Option 2: Other

For example the content file getIP.yml as below

[vagrant@ansible_controller ~]$ cat getIP.yml
---
- hosts: servers
  gather_facts: yes
  tasks:
  - name: Get IP address remote server
    debug:
      msg: "{{ hostvars[inventory_hostname]['ansible_env'].SSH_CONNECTION.split(' ')[2] }}"

The output on terminal

[vagrant@ansible_controller ~]$ ansible-playbook getIP.yml -i .ansible/hosts

PLAY [servers] *************************************************************************************************************

TASK [Gathering Facts] *************************************************************************************************
ok: [server1]

TASK [Get IP address remote server] ************************************************************************************
ok: [server1] => {
    "msg": "192.168.3.11"
}

PLAY RECAP *************************************************************************************************************
server1                    : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Option 3: lookup and dig

For example the content file getIP.yml as below

[vagrant@ansible_controller ~]$ cat getIP.yml
---
- hosts: servers
  tasks:
  - name: Test hosts list
    debug:
      msg: "{{ lookup('dig', ansible_host) }}"

Make sure you have proper SSH access to the remote server and the necessary permissions to gather facts from it.

Conclusion

You have to use Ansible get IP address remote server. I hope will this your helpful. Thank you for reading the DevopsRoles page!