requirements.md

VMs OS and Workstation requirements

Requirements for all Docker Swarm cluster servers and administrator workstation.

TOC:

• 1. On VMs
  • 1.1 Firewall
  • 1.2 OS user
  • 1.3 Sudoers file
• 2. On ansible workstation (admin node)
  • 2.1 Generate SSH keys
  • 2.2 SSH folder and file permissions
  • 2.3 Setup passwordless SSH

1. On VMs

1.1 Firewall

❗ It is recommended to disable the firewall on your VMs, to avoid various unwanted problems during installation!

Debian/Ubuntu

sudo ufw disable

RedHat/Rocky

sudo systemctl disable --now firewalld

1.2 OS user

Create new OS user for a ansible tasks on all cluster VMs:

Debian/Ubuntu

sudo adduser hladmin

RedHat/Rocky

sudo useradd hladmin

sudo passwd hladmin

1.3 Sudoers file

Add newly created user to sudoers file (for passwordless sudo):

sudo su -

echo -e "\n# Allow without a password\nhladmin        ALL=(ALL)       NOPASSWD: ALL" >> /etc/sudoers

exit

2. On ansible workstation (admin node)

2.1 Generate SSH keys

Create required directory

mkdir -p ~/.ssh/

Generate new SSH key:

ssh-keygen -f ~/.ssh/id_rsa -N ""

2.2 SSH folder and file permissions

chmod 700 ~/.ssh

chmod 644 ~/.ssh/id_rsa.pub

chmod 600 ~/.ssh/id_rsa

chmod 600 ~/.ssh/authorized_keys

2.3 Setup passwordless SSH

Distribute the SSH public key to all servers:

• use newly created user for ansible tasks:

ssh-copy-id hladmin@127.0.0.11

SSH without password

ssh hladmin@127.0.0.11