Cursor SSH:Setup

This guide explains how to configure Cursor IDE to connect to a Raspberry Pi through the VPS SSH port forward.

Overview

Cursor IDE (like VS Code) supports remote development via SSH. To connect to your Raspberry Pi through the VPS:

Your Computer → Cursor IDE → SSH → VPS:22223 → VPN Tunnel → Raspberry Pi (10.8.0.3:22)

Prerequisites

✅ SSH Port Forward Configured (Already done)

  * Port forward: 22223 → 10.8.0.3:22

  * Verify: sudo ssh-forward list

✅ IONOS Firewall Rule (Required)

  * Port 22223 must be allowed in IONOS Cloud Panel

  * See: [SSH Port Forwarding Guide](Ssh-Port-Forwarding.md)

Raspberry Pi Requirements:

  * SSH server enabled

  * Root SSH access enabled (see step 1)

  * Network connectivity via VPN

Step-by-Step Configuration

1. Enable SSH and Root Access on Raspberry Pi

Enable SSH server (on Raspberry Pi):

sudo systemctl enable ssh
sudo systemctl start ssh

Or via raspi-config:

sudo raspi-config
== Navigate to: Interfacing Options → SSH → Enable ==

Enable root SSH access (on Raspberry Pi):

== Set root password (if not already set) ==
r

== Enable root login via SSH ==
sudo sed -i 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config
== Or if using password auth: ==
sudo sed -i 's/#PermitRootLogin yes/PermitRootLogin yes/' /etc/ssh/sshd_config

== Restart SSH service ==
sudo systemctl restart ssh

Verify SSH is running:

sudo systemctl status ssh
== Should show: active (running) ==

Test root SSH access:

ssh root@localhost
== Should connect as root ==

2. Configure SSH on Your Local Machine

Create or edit ~/.ssh/config on your local machine (where Cursor is installed):

==== On your local machine (not the VPS) ====
nano ~/.ssh/config

Add the following configuration:

Host raspberrypi
    HostName 87.106.61.62
    Port 22223
    User root
    IdentityFile ~/.ssh/id_rsa
    ServerAliveInterval 60
    ServerAliveCountMax 3
    StrictHostKeyChecking no
    UserKnownHostsFile ~/.ssh/known_hosts

Configuration Options:

Host raspberrypi: Alias name (use any name you prefer)

HostName 87.106.61.62: Your VPS public IP

Port 22223: External port for Raspberry Pi forward

User root: Username on Raspberry Pi (using root for Cursor)

IdentityFile ~/.ssh/id_rsa: Path to your SSH private key

ServerAliveInterval 60: Keep connection alive (prevents timeouts)

3. Set Up SSH Key Authentication (Recommended)

On your local machine:

Generate SSH key pair (if you don't have one):

   ssh-keygen -t ed25519 -C "cursor-raspberrypi"
=== Or use RSA: ssh-keygen -t rsa -b 4096 ===

Copy public key to Raspberry Pi (as root):

   ssh-copy-id -p 22223 root@87.106.61.62
=== Or manually: ===
   cat ~/.ssh/id_ed25519.pub | ssh -p 22223 root@87.106.61.62 "mkdir -p ~/.ssh && chmod 700 ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

Test passwordless connection:

   ssh -p 22223 root@87.106.61.62
=== Should connect without password prompt ===

4. Configure Cursor IDE

Install Remote SSH Extension (if not already installed):

  * Open Cursor

  * Go to Extensions (Ctrl+Shift+X / Cmd+Shift+X)

  * Search for "Remote - SSH" or "Anysphere Remote SSH"

  * Install the extension

Connect to Raspberry Pi:

  * Press F1 or Ctrl+Shift+P (Cmd+Shift+P on Mac)

  * Type: Remote-SSH: Connect to Host...

  * Select: raspberrypi (or the Host name from your SSH config)

  * Or enter directly: root@87.106.61.62:22223

First Connection Setup:

  * Cursor will install the Cursor server on the Raspberry Pi

  * This may take a few minutes on first connection

  * You'll see a notification: "Installing Cursor Server..."

Select Platform (if prompted):

  * Choose: Linux → arm64 or armv7l (depending on your Pi model)

5. Troubleshooting Connection Issues

Issue: Connection Timeout

Check IONOS Firewall:

Verify port 22223 is allowed in IONOS Cloud Panel

Check rule priority (lower numbers = higher priority)

Test SSH connection manually:

ssh -v -p 22223 root@87.106.61.62

Check port forward on VPS:

== On VPS ==
sudo ssh-forward list
iptables -t nat -L PREROUTING -n | grep 22223

Issue: "Permission Denied"

Verify SSH key is authorized:

===== On Raspberry Pi =====
cat ~/.ssh/authorized_keys
== Should contain your public key ==

Check SSH server logs:

== On Raspberry Pi ==
sudo tail -f /var/log/auth.log
== Attempt connection and watch for errors ==

Verify user permissions:

== On Raspberry Pi ==
ls -la ~/.ssh/
== Should be: drwx------ (700) for .ssh directory ==
== Should be: -rw------- (600) for authorized_keys ==

Issue: Cursor Server Installation Fails

Clear Cursor server cache:

===== On Raspberry Pi =====
rm -rf ~/.cursor-server

Check disk space:

== On Raspberry Pi ==
df -h

Check Python/Node.js availability:

== On Raspberry Pi ==
python3 --version
node --version  # If available

Issue: Slow Connection

Optimize SSH config: Add to ~/.ssh/config:

Host raspberrypi
    Compression yes
    IPQoS throughput

Use SSH multiplexing:

Host raspberrypi
    ControlMaster auto
    ControlPath ~/.ssh/control-%h-%p-%r
    ControlPersist 10m

6. Verify Complete Setup

Test checklist:

[ ] SSH port forward is active: sudo ssh-forward list

[ ] IONOS firewall allows port 22223

[ ] Can SSH manually: ssh -p 22223 root@87.106.61.62

[ ] SSH key authentication works (no password prompt)

[ ] Cursor can connect via Remote SSH

[ ] Cursor server installed on Raspberry Pi

[ ] Can open files and use terminal in Cursor

7. Multiple Devices Configuration

If you have multiple devices, add separate entries in ~/.ssh/config:

Host synology
    HostName 87.106.61.62
    Port 22222
    User admin
    IdentityFile ~/.ssh/id_rsa

Host raspberrypi
    HostName 87.106.61.62
    Port 22223
    User root
    IdentityFile ~/.ssh/id_rsa

Host device-03
    HostName 87.106.61.62
    Port 22223
    User user
    IdentityFile ~/.ssh/id_rsa

Security Best Practices

Note: This guide uses root user for Cursor connections to avoid permission issues. While convenient for development, be aware of security implications.

Use SSH Keys: Always use key-based authentication instead of passwords

Disable Password Auth for Root: On Raspberry Pi, edit `/etc/ssh/sshd_config`:

   PermitRootLogin prohibit-password
   PasswordAuthentication no
   PubkeyAuthentication yes

  This allows root login only with SSH keys, not passwords.
  Then restart: sudo systemctl restart ssh

Use Strong Keys: Use ED25519 or RSA 4096-bit keys

Limit Access: Consider restricting SSH access to specific IPs if possible

Keep Updated: Regularly update Raspberry Pi OS and SSH server

Root Access Consideration: Using root avoids permission issues in Cursor but increases security risk. Consider using a dedicated user with sudo if security is a concern.

Advanced Configuration

SSH Config with Jump Host (Alternative)

If you want to connect through the VPS as a jump host:

Host vps
    HostName 87.106.61.62
    User root
    IdentityFile ~/.ssh/id_rsa

Host raspberrypi
    HostName 10.8.0.3
    User root
    ProxyJump vps
    IdentityFile ~/.ssh/id_rsa

Port Forwarding in SSH Config

You can also create local port forwards in your SSH config:

Host raspberrypi
    HostName 87.106.61.62
    Port 22223
    User root
    LocalForward 8080 localhost:8080  # Forward local port 8080 to Pi's 8080

Quick Reference

Component	Value
VPS Public IP	87.106.61.62
Raspberry Pi External Port	22223
Raspberry Pi VPN IP	10.8.0.3
Raspberry Pi SSH Port	22
Default User	root

SSH Command:

ssh -p 22223 root@87.106.61.62

Cursor Connection:

Host: raspberrypi (from SSH config)

Or: root@87.106.61.62:22223