scm-setup/jump-host.md

Jump Host Setup

• Install Ubuntu 22.04 Server
• Install tailscale

$ curl -fsSL https://pkgs.tailscale.com/stable/ubuntu/jammy.noarmor.gpg | sudo tee /usr/share/keyrings/tailscale-archive-keyring.gpg >/dev/null
$ curl -fsSL https://pkgs.tailscale.com/stable/ubuntu/jammy.tailscale-keyring.list | sudo tee /etc/apt/sources.list.d/tailscale.list

# Install Tailscale:

$ sudo apt-get update
$ sudo apt-get install tailscale

# Connect your machine to your Tailscale network and authenticate in your browser using `mitech5004ext@gmail.com` account

$ sudo tailscale up
# You’re connected! You can find your Tailscale IPv4 address by running:

$ tailscale ip -4

• Setup User

$ sudo useradd mitechextusers

• Disable user interactive Shell by updating sshd_config

$ sudo nano /etc/ssh/sshd_config

# Load the new configuration
$ sudo systemctl restart ssh

• /etc/ssh/sshd_config

...
Match User mitechextusers
  PermitTTY no

• Upload user ssh key to sftp server under mitech user

• Login to sftp server under mitech user

• Copy uploaded ssh key from sftp server to jump-host-ext

$ cat ./id_rsa.pub | ssh mitechextusers@10.0.0.149 "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

• Establish Tailscale on client machine using mitech5004ext@gmail account
• On client machine, test the SSH Reverse Tunnel connection

$ ssh -L 3000:172.30.30.21:3000 -L 29419:172.30.30.21:29419 mitechextusers@jump-host-ext

• Update Client machine host file

127.0.0.1 dev.mitech.com.sg

• Browse the site Gitea
• Git clone a repo to test cloning

User credential

• jump-host-ext
  • mitech: root
  • mitechextusers: tailscale client ssh tunnel access