DevOps Classroom Series – 17/Dec/2020

Configuring Ansible

• Create a user or use an existing with admin privileges
• In this scenario lets create a user called as devops with admin permissions on both ansible control server and node
  • Ensure Password based authentication is enabled. Modify PasswordAuthentication to yes in the file /etc/ssh/sshd_config
  • Create a user called as devops

  sudo adduser devops
  

  
  • Now lets give sudo permissions which donot ask password for user devops

  sudo visudo
  # add entry as shown below and use Ctrl+x
  

  
  • Lets restart sshd service

  sudo service sshd restart
  

  • Login as devops user in to the system
  • Execute any sudo command and it should not ask for password
• Lets repeat the above steps for the node-1
• Ensure you are able to login from ansible control server to node-1
• Now execute the command

ansible -i inventory -k -m ping all

• But when we are automating, is it possible to give password every time.
• Now lets configure further so that ansible doesnot require password while communicating with nodes. For this we use classical linux approach of key based authentication
• Login into ansible control server and create a key pair

ssh-keygen

• As a result of this command a public and private key will be create in ~/.ssh
• Now lets try to copy the public key on ansible control server into node-1 so that node-1 doesnt ask password when ansible control server is trying to login as devops user.

ssh-copy-id devops@<node-1-ipaddress>

• Now try logging in from ansible control server to node-1 using ipadress
• Now lets run the ansible command again

ansible -m ping -i inventory all

• Overall Summary
• Exercise: Try to configure centos node to ansible control server