SSH Access Guide

Complete guide for accessing NazDocker Lab via SSH.

🔑 Local SSH Access

Basic Connection 

# Connect to admin user
ssh admin@localhost -p 2222

# Connect to other users
ssh user1@localhost -p 2222
ssh user2@localhost -p 2222
# ... etc

# Connect as root
ssh root@localhost -p 2222

Default Credentials

Username Default Password Sudo Access
admin admin123 ✅ Yes
user1 user123 ❌ No
user2 user123 ❌ No
user3 user123 ❌ No
user4 user123 ❌ No
user5 user123 ❌ No
root root123 ✅ Yes

🌐 Public SSH Access

Via Playit.gg Tunneling

  1. Configure tunnel in .env file: 
    PLAYIT_SECRET_KEY=your_secret_key_here
  2. Check tunnel status: 
    docker-compose -f docker-compose.ubuntu.yml logs lab-environment-ubuntu | grep -i "playit"
  3. Connect via public URL: 
    ssh admin@your-tunnel-url.playit.gg -p 12345

Tunnel Management 

# Check tunnel logs
docker-compose -f docker-compose.ubuntu.yml logs lab-environment-ubuntu | grep -i "playit\|tunnel\|url"

# Follow logs in real-time
docker-compose -f docker-compose.ubuntu.yml logs -f lab-environment-ubuntu

# Check playit.gg process
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu ps aux | grep playit

🔧 SSH Configuration

SSH Service Management 

# Check SSH service status
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu service ssh status

# Restart SSH service
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu service ssh restart

# Check SSH configuration
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu cat /etc/ssh/sshd_config

# Test SSH locally
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu ssh localhost

SSH Configuration Options 

# View current SSH configuration
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu cat /etc/ssh/sshd_config

# Key configuration options:
# PasswordAuthentication yes
# PermitRootLogin yes
# PubkeyAuthentication yes
# Port 22

🔐 SSH Key Authentication

Generate SSH Keys 

# Generate SSH key pair
ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

# Generate Ed25519 key (recommended)
ssh-keygen -t ed25519 -C "your_email@example.com"

Add SSH Keys to Container

Method 1: Mount SSH Keys 

# In docker-compose.ubuntu.yml
volumes:
  - ~/.ssh/id_rsa.pub:/home/admin/.ssh/authorized_keys:ro
  - ~/.ssh/id_rsa.pub:/home/user1/.ssh/authorized_keys:ro

Method 2: Container Shell 

# Access container
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu bash

# Add SSH key for admin
mkdir -p /home/admin/.ssh
echo "your_public_key_here" >> /home/admin/.ssh/authorized_keys
chown -R admin:admin /home/admin/.ssh
chmod 700 /home/admin/.ssh
chmod 600 /home/admin/.ssh/authorized_keys

Method 3: Dockerfile 

# In Dockerfile.ubuntu
RUN mkdir -p /home/admin/.ssh && \
    echo "your_public_key_here" >> /home/admin/.ssh/authorized_keys && \
    chown -R admin:admin /home/admin/.ssh && \
    chmod 700 /home/admin/.ssh && \
    chmod 600 /home/admin/.ssh/authorized_keys

Connect with SSH Key 

# Connect using SSH key
ssh -i ~/.ssh/id_rsa admin@localhost -p 2222

# Connect with specific key
ssh -i ~/.ssh/my_key admin@localhost -p 2222

# Connect with verbose output
ssh -v admin@localhost -p 2222

🔧 SSH Client Configuration

SSH Config File

Create ~/.ssh/config for easier connections:

# NazDocker Lab configuration
Host nazdocker-lab
    HostName localhost
    Port 2222
    User admin
    IdentityFile ~/.ssh/id_rsa
    ServerAliveInterval 60
    ServerAliveCountMax 3

Host nazdocker-lab-user1
    HostName localhost
    Port 2222
    User user1
    IdentityFile ~/.ssh/id_rsa
    ServerAliveInterval 60
    ServerAliveCountMax 3

Using SSH Config 

# Connect using config
ssh nazdocker-lab

# Connect to specific user
ssh nazdocker-lab-user1

🛡️ Security Best Practices

Password Security 

# Change default passwords immediately
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu bash

# Change passwords interactively
passwd admin
passwd user1
# ... etc

SSH Key Security 

# Set proper permissions
chmod 700 ~/.ssh
chmod 600 ~/.ssh/id_rsa
chmod 644 ~/.ssh/id_rsa.pub

# Use strong key types
ssh-keygen -t ed25519 -C "your_email@example.com"

SSH Configuration Security 

# Disable password authentication (if using keys)
# In /etc/ssh/sshd_config
PasswordAuthentication no

# Disable root login (recommended)
PermitRootLogin no

# Restrict users (optional)
AllowUsers admin user1 user2 user3 user4 user5

🔍 Troubleshooting SSH

Connection Issues 

# Check if container is running
docker-compose -f docker-compose.ubuntu.yml ps

# Check SSH service
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu service ssh status

# Check port mapping
docker port student-lab-ubuntu

# Test SSH locally
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu ssh localhost

Authentication Issues 

# Check user accounts
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu bash -c "
cat /etc/passwd | grep -E ':(/bin/bash|/bin/sh)$'
"

# Reset password
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu bash -c "
echo 'admin:admin123' | chpasswd
"

# Check SSH logs
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu tail -f /var/log/auth.log

Key Authentication Issues 

# Check key permissions
ls -la ~/.ssh/

# Check authorized_keys
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu cat /home/admin/.ssh/authorized_keys

# Test key authentication
ssh -v -i ~/.ssh/id_rsa admin@localhost -p 2222

📊 SSH Monitoring

Connection Monitoring 

# Check active SSH connections
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu who

# Check SSH process
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu ps aux | grep sshd

# Monitor SSH logs
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu tail -f /var/log/auth.log

Security Auditing 

# Check failed login attempts
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu bash -c "
grep 'Failed password' /var/log/auth.log
"

# Check successful logins
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu bash -c "
grep 'Accepted password' /var/log/auth.log
"

# Check SSH configuration
docker-compose -f docker-compose.ubuntu.yml exec lab-environment-ubuntu bash -c "
cat /etc/ssh/sshd_config | grep -E '(PasswordAuthentication|PermitRootLogin|PubkeyAuthentication)'
"

🔧 Advanced SSH Features

Port Forwarding 

# Local port forwarding
ssh -L 8080:localhost:80 admin@localhost -p 2222

# Remote port forwarding
ssh -R 8080:localhost:80 admin@localhost -p 2222

# Dynamic port forwarding (SOCKS proxy)
ssh -D 1080 admin@localhost -p 2222

File Transfer 

# Copy file to container
scp -P 2222 file.txt admin@localhost:/home/admin/

# Copy file from container
scp -P 2222 admin@localhost:/home/admin/file.txt ./

# Copy directory
scp -P 2222 -r directory/ admin@localhost:/home/admin/

X11 Forwarding 

# Enable X11 forwarding
ssh -X admin@localhost -p 2222

# Trusted X11 forwarding
ssh -Y admin@localhost -p 2222

🔗 Related Topics