Installation of Ansible on CentOS 7 | RHEL | OpenSuse | Ubuntu

 Hello Guys!! 

In this post let's explore the installation options for Ansible Core. We can get the detailed Documentation provided by Ansible in the Installation Guide. I've also gone through the Amazing Book : Ansible for DevOps  Here he explained that beginners can start with playing in Laptop by setting up the Virtual Boxes for Ansible learnings. 

Today I have started experimenting with Ansible installation on the CentOS 7 Vagrant box, As you know Ansible is from the RedHat.

Ansible having 3300+ modules freely available. At the end of the installation, we can test the connectivity with the 'ping' and 'shell' module which will be referred to the inventory hosts which is present in the "/etc/ansible/hosts" location.

Prerequisites for Ansible installation

• Create Vagrant Boxes where Ansible engine runs on the master node and SSH-Agents will run on two different nodes.
• PasswordAuthentication enable for sshd_config
• SSH Connectivity with ssh-keygen

Ansible ready to use on Vagrant boxes

My understanding review about Ansible Architecture

Ansible Architecture 

Steps for Installing and Configuration of Ansible on CentOS 7

Step 1. Installation of yum repo and Ansible

To install the Ansible using yum package manager we must get update the repo

Alternative Vagrant optons as

Vagrant.configure(2) do |config|
    #config.vm.box = "centos/8"
    config.vm.boot_timeout=600
    config.landrush.enabled = true
  
    config.vm.define "mstr" do |mstr|
      mstr.vm.host_name = "mstr.devopshunter.com"
      mstr.vm.box= "ansible/tower"
      mstr.vm.network "private_network", ip: "192.168.33.100"
      mstr.vm.provider "virtualbox" do |vb|
        vb.cpus = "2"
        vb.memory = "2048"
      end
    end
    config.vm.box = "centos/8"  
    config.vm.define "node1" do |node1|
      node1.vm.network "private_network", ip: "192.168.33.110"
      node1.vm.hostname = "node1.devopshunter.com"
      node1.vm.provider "virtualbox" do |vb|
        vb.cpus = "2"
        vb.memory = "1024"
      end
    end
   
    config.vm.define "node2" do |node2|
      node2.vm.network "private_network", ip: "192.168.33.120"
      node2.vm.hostname = "node2.devopshunter.com"
      node2.vm.provider "virtualbox" do |vb|
        vb.cpus = "2"
        vb.memory = "1024"
      end
    end  
  end
  

You can run `vagrant up' to bring up the 3 boxes as defined in the

sudo yum install -y epel-release
sudo yum install -y ansible

# To get the latest version of ansible use the following 

# Remove ansible older version
sudo yum remove -y ansible

# Install python3 includes pip3
sudo yum install -y python3

wget https://bootstrap.pypa.io/get-pip.py
python3 get-pip.py
python3 -m pip install --upgrade pip
pip3 install ansible==4.6.0 --user
ansible --version # this will show warning older version 
python3 -c 'from ansible_collections.ansible_release import ansible_version; print(ansible_version)'

Step 2: Change sshd_config file on Vagrant based CentOS box

Better to edit with root user the /etc/ssh/sshd_config cotaining PasswordAuthentication no to PasswordAuthentication yes and restart the sshd services.

vi /etc/ssh/sshd_config
# Search and comment 
#PasswordAuthentication no
# Search uncomment for yes value
PasswordAuthentication yes

Save the file and restart the sshd services on all the CentOS boxes.

systemctl restart sshd # Restart sshd service
systemctl status  sshd #Check the status

Confirmation on the sshd_config changes as shown below:

ssh_config modified and restart service in CentOS 7

same step 2 ssh_config changes can be repeated on the all target boxes as well.

ssh service restart on remote nodes

Step 3: Ansible inventory creation on Controller

Update the hostname and IP address correctly mapped on VMs. There are many ways to add the machines on your Ansible Engine running VM. Same IP or VM can be part of multiple groups also allowed. Example host2 is member in appservers and also dbserver due to its capabilities we can assign.

[nodes]
192.168.33.210
192.168.33.220

Step 4: SSH Key Generation with RSA algorithm.

We can use any algorithm

ssh-keygen -t rsa -b 4096 -C "ansible-engine"
 ls -rlta ~/.ssh 
 ssh-copy-id -i ~/.ssh/id_rsa.pub vagrant@192.168.33.210
 # Say 'yes' to add to known_hosts
 # Enter the password to connect remote host 
 # Validate
 ssh vagrant@192.168.33.210
 exit # exit from remote host
 # Repeat above steps for remaining hosts
 ssh-copy-id -i ~/.ssh/id_rsa.pub vagrant@192.168.33.220
 ssh vagrant@192.168.33.220
 exit 

ssh-keygen for ansible 

Observe that two rsa files created in the ~/.ssh folder one is key and other one with .pub extentiona is public key

Step 5: Adding SSH Key to Authorized keys of remote hosts

ssh-copy-id -i ~/.ssh/id_rsa.pub vagrant@192.168.33.210
ssh-copy-id -i ~/.ssh/id_rsa.pub vagrant@192.168.33.220

SSH copy id

Regular test-case after Ansible installation we have multiple options test with the ping module:

ansible -m ping all
ansible -m ping nodes

Ansible installation on Ubuntu

As we have multiple ways to install the Ansible Core on any Linux platform, Here we will see the option to install it on Ubuntu 20.04.  Specialty of this is we will be getting the latest installation because the repository will be update on your Ubuntu System. 

You can see the video session for Ansible installation on Ubuntu with latest repository updated : 

 sudo apt update
 sudo apt install software-properties-common
 sudo add-apt-repository --yes --update ppa:ansible/ansible
 sudo apt install ansible

 

Please write your feedback on this post, and also your experiment problems if in case you followed my steps.