ansible SSH

Checkout my blog of using automation of setting up an initial user https://devops4solutions.com/automate-ansible-playbook-deployment-on-aws-ec2/

In this blog we will Setup SSH Key and initial user using Ansible Playbook

To create new user on ubuntu system, you need the following things:

1. Username/Password
2. Public Key of the user
3. You will first create a user on one machine. Machine can be your local workstation also
4. Generate ssh-key for this
5. Put the public key of that user to the remote hosts.
6. Add that user to the sudoers.d file

Steps:

sudo -i
useradd -m -s /bin/bash devops
passwd devops
echo -e ‘devops\tALL=(ALL)\tNOPASSWD:\tALL’ > /etc/sudoers.d/devops_Encrypt your password
_sudo apt install whois -y__mkpasswd — method=SHA-512
TYPE THE PASSWORD ‘devops’

Generate a new SSH-key

1. Login as a devops user

ssh-keygen -t rsa

It will generate the public and private key file for the devops user.

Now we have to add this public key to all the remote hosts.

Create Ansible playbook “add-user-ssh.yml”

• Add a devops user
• Now we want to disable the Password Authentication on all the remote hosts.This means no user/root user can login to the system by using password. They have to use the SSH keys only.

---

• hosts: all
  vars:
  • devops_password: 'abcddefsfdfdfdfdfdfdfdfdfdfd'
    gather_facts: no
    remote_user: ubuntu
    become: truetasks:- name: Add a new user named devops
    user:
    name: devops
    shell: /bin/bash
    password: "{{ devops_password }}"- name: Add devops user to the sudoers
    copy:
    dest: "/etc/sudoers.d/devops"
    content: "devops ALL=(ALL) NOPASSWD: ALL"- name: Deploy SSH Key
    authorized_key: user=devops
    key="{{ lookup('file', '/home/devops/.ssh/id_rsa.pub') }}"
    state=present- name: Disable Password Authentication
    lineinfile:
    dest=/etc/ssh/sshd_config
    regexp='^PasswordAuthentication'
    line="PasswordAuthentication no"
    state=present
    backup=yes_- name: Disable Root Login
    lineinfile:
    dest=/etc/ssh/sshd_config
    regexp='^PermitRootLogin'
    line="PermitRootLogin no"
    state=present
    backup=yes
    notify:
  • restart ssh_handlers:
• name: restart ssh
  service:
  name=sshd
  state=restarted

Run the playbook

ansible-playbook add-user-ssh.yml -i hosts

Validate Disable Password Authentication

$ ssh servername -o PubkeyAuthentication=no

You will get the “Permission Denied(public key)