SSH and tmux: Essential Tools for Remote Development

Introduction

Secure Shell (SSH) and tmux are essential tools for modern remote development and server management. SSH provides secure access to remote systems, while tmux enables persistent terminal sessions that survive network disconnections. Whether you’re managing servers, developing on remote machines, or collaborating with team members, mastering these tools will significantly boost your productivity.

SSH: Secure Remote Access

Choosing an SSH Client

The default SSH client for both macOS and Linux systems is the built-in terminal. For Windows users, several alternatives are available:

Terminal (Mac and Linux): Connect using ssh username@host in the terminal
Windows Options: PuTTY, Bitvise SSH Client, MobaXterm, or Windows Subsystem for Linux (WSL)
VS Code: Built-in terminal with Remote-SSH extension for seamless development

Essential SSH Tricks

1. Key-Based Authentication

# Generate SSH key pair
ssh-keygen -t ed25519 -C "your_email@example.com"

# Copy public key to remote server
ssh-copy-id user@remote-server

# Or manually copy the key
cat ~/.ssh/id_ed25519.pub | ssh user@remote-server "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

2. Execute Commands Remotely

# Run a single command
ssh user@remote-server "ls -la /home/user"

# Run multiple commands
ssh user@remote-server "cd /project && git pull && make build"

3. Port Forwarding and Tunneling

# Local port forwarding (forward local port to remote)
ssh -L 8888:localhost:8888 user@remote-server

# Remote port forwarding (forward remote port to local)
ssh -R 8888:localhost:8888 user@remote-server

# Dynamic SOCKS proxy
ssh -D 1080 user@remote-server

4. Jupyter Notebook Tunneling

# On remote server
jupyter notebook --no-browser --port=8888 --ip=0.0.0.0

# On local machine
ssh -L 8889:localhost:8888 user@remote-server

# Access via http://localhost:8889 in your browser

tmux: Terminal Multiplexer

What is tmux?

tmux is a terminal multiplexer that allows you to:

Create persistent terminal sessions that survive network disconnections
Split terminals into multiple panes
Create multiple windows within a session
Share sessions with other users
Detach and reattach to sessions

Installing tmux

# Ubuntu/Debian
sudo apt update && sudo apt install tmux

# CentOS/RHEL/Fedora
sudo yum install tmux  # or sudo dnf install tmux

# macOS
brew install tmux

# Arch Linux
sudo pacman -S tmux

Basic tmux Commands

Session Management

# Start new session
tmux

# Start named session
tmux new-session -s mysession

# List sessions
tmux list-sessions  # or tmux ls

# Attach to session
tmux attach-session -t mysession  # or tmux a -t mysession

# Detach from session
# Press Ctrl+b, then d

Window Management

# Create new window
Ctrl+b, c

# Switch between windows
Ctrl+b, n  # next window
Ctrl+b, p  # previous window
Ctrl+b, <number>  # switch to specific window

# Rename current window
Ctrl+b, ,

# List windows
Ctrl+b, w

Pane Management

# Split pane horizontally
Ctrl+b, "

# Split pane vertically
Ctrl+b, %

# Switch between panes
Ctrl+b, <arrow-keys>

# Resize panes
Ctrl+b, Ctrl+<arrow-keys>

# Close current pane
Ctrl+b, x

Advanced tmux Features

1. Copy Mode

# Enter copy mode
Ctrl+b, [

# Navigate with arrow keys or vim keys
# Press Space to start selection
# Press Enter to copy
# Paste with Ctrl+b, ]

2. tmux Configuration

Create ~/.tmux.conf for custom settings:

# Enable mouse support
set -g mouse on

# Set base index to 1
set -g base-index 1
setw -g pane-base-index 1

# Increase scrollback buffer
set -g history-limit 10000

# Enable vi keys
setw -g mode-keys vi

# Status bar customization
set -g status-bg black
set -g status-fg white
set -g status-left '#[fg=green]#S'

# Create shared session
tmux new-session -s shared -d

# Allow others to attach
tmux attach-session -t shared

# Other users can attach with
tmux attach-session -t shared

Practical tmux Workflows

1. Development Environment

# Start development session
tmux new-session -s dev -d

# Split into multiple panes
tmux split-window -h  # Split vertically
tmux split-window -v  # Split horizontally

# Arrange panes for development
# Left: Code editor
# Top-right: Terminal for running tests
# Bottom-right: Git status and logs

2. Server Monitoring

# Create monitoring session
tmux new-session -s monitor -d

# Split into monitoring panes
tmux split-window -h
tmux split-window -v

# In different panes:
# htop
# iotop
# netstat -tulpn
# tail -f /var/log/syslog

3. Collaborative Debugging

# Create shared debugging session
tmux new-session -s debug -d

# Share session with team member
tmux attach-session -t debug

# Both users can see the same terminal
# Useful for pair programming or debugging

Integration: SSH + tmux

Best Practices for Remote Development

Always use tmux for long-running processes

# Start tmux session on remote server
ssh user@server "tmux new-session -s work -d"
   
# Attach to session
ssh user@server -t "tmux attach-session -t work"

Use tmux for build processes

# Start build in tmux
tmux new-session -s build -d
tmux send-keys -t build "make build" Enter
   
# Detach and let it run
tmux detach-client -s build
   
# Check progress later
tmux attach-session -t build

Persistent development sessions

# Create development session
tmux new-session -s dev -d
   
# Set up your development environment
tmux send-keys -t dev "cd /project" Enter
tmux send-keys -t dev "vim src/main.py" Enter
   
# Detach and reconnect later
tmux detach-client -s dev

Troubleshooting Common Issues

SSH Connection Drops

# Add to ~/.ssh/config
Host *
    ServerAliveInterval 60
    ServerAliveCountMax 3
    TCPKeepAlive yes

tmux Session Recovery

# List all sessions
tmux list-sessions

# Attach to specific session
tmux attach-session -t session_name

# Kill broken session
tmux kill-session -t session_name

Conclusion

SSH and tmux form a powerful combination for remote development. SSH provides secure access to remote systems, while tmux ensures your work persists through network interruptions. By mastering these tools, you can:

Work efficiently on remote servers
Maintain persistent development sessions
Collaborate effectively with team members
Handle network interruptions gracefully
Build robust remote development workflows

Start with the basic commands and gradually incorporate more advanced features into your daily workflow. The investment in learning these tools will pay dividends in your productivity and development experience.