Ansible Role: SSH

This role sets the environment on ansible hosts (machines managed by ansible) by creating a common user and setting needed keys.

Creates a user to all the hosts groups (master_node and nodes)
Adds him in sudoer group
Configures sudo without password
Creates ed25519 ssh key on master node
Defines the authorized_keys file
Add all nodes to the known_hosts file (in the master node)
Defines a custom name for the ssh keys

Requirements

Root Access

This role requires root access, so either run it in a playbook with a global become: yes, or invoke the role in your playbook like:

- hosts: master_node:nodes
  roles:
    - role: ansible-role-ssh
      become: yes

Note that you can also set the become: yes value in the ansible.cfg file, but use a local file located in the same directory as your playbook.

Prompt

We use interactive input (prompt) for the user password. The benefit is that the password is automatically encrypted in SHA-512 by default (see the example playbook).

Other values are available :

bcrypt
md5_crypt
sha256_crypt
sha512_crypt

More information here.

Modules

Nodes Groups

Master node

Although this node is used as a simple control node to connect to the clients, It is unique and used to create the ssh keys. Then, the public key is sent to the client nodes.

If the ansible playbook is launched again (by adding some new client nodes), the keys are not generated again.

Nodes

These nodes are the clients nodes. The master node can connect to them (by using the user account created by this role) without being prompted for a user and a password.

Role Variables

Default values (`defaults/main.yml`)

User configuration, the user can be set as a sudo user :

# User configuration.
usr_name: "user"
usr_dir: "/home/{{ usr_name }}"
is_usr_sudo: false

SSH configuration (with custom key names) :

ssh_dir: "{{ usr_dir }}/.ssh"
ssh_priv_key: "{{ ssh_dir }}/{{ usr_name }}"
ssh_pub_key: "{{ ssh_priv_key }}.pub"

Role Tasks

The role is divided into different tasks, the tasks/main.yml file include these tasks :

---
# User configuration.
- include_tasks: user.yml

# Setup/install tasks.
- include_tasks: create_key.yml
- include_tasks: setup_key.yml

# SSH configuration.
- include_tasks: ssh.yml

Example Playbook

- hosts: master_node:nodes
  become: yes
  roles:
    - ansible-role-ssh

  vars_prompt:
    - name: usr_passwd
      prompt: Enter user password
      unsafe: yes
      private: yes
      encrypt: sha512_crypt
      confirm: yes

Example Inventory

[master_node]
node1

[nodes]
node2
node3
node4
node5

Ph4ntom01/ansible-role-ssh