Tunnel RTSP streams from Balena devices

src/framegrab/cli/balena_rtsp_tunnel.py

@@ -0,0 +1,35 @@
+import os
+import subprocess
+from pathlib import Path
+
+import click
+
+COMMAND_NAME = "balena-rtsp-tunnel"
+
+
+@click.command(COMMAND_NAME)
+@click.argument("device_id")
+@click.argument("rtsp_ip")
+@click.argument("pem_file", required=False)
+@click.option("-l", "--local-port", default=8554, help="Local port for RTSP stream")
+@click.option("-r", "--remote-port", default=554, help="Remote RTSP port")
+def balena_rtsp_tunnel(
+    device_id: str, rtsp_ip: str, pem_file: str = None, local_port: int = 8554, remote_port: int = 554
+):
+    """Tunnel an RTSP stream from a Balena device via SSH tunneling
+
+    \b
+    DEVICE_ID: Balena device ID
+    RTSP_IP: IP address of RTSP camera (e.g. 192.168.2.219)
+    PEM_FILE: Optional path to PEM file for SSH authentication
+    """
+    if os.name == "nt":
+        raise RuntimeError(
+            f"{COMMAND_NAME} is not supported on Windows. Try running this command on a Unix-like system."
+        )
+
+    script_path = (
+        Path(__file__).parent / "balena_rtsp_tunnel.sh"
+    )  # Poetry packages .sh files alongside .py files, so this works
+    cmd = [str(script_path), device_id, rtsp_ip, pem_file or "", str(local_port), str(remote_port)]
+    subprocess.run(cmd)

src/framegrab/cli/balena_rtsp_tunnel.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+
+# Check arguments
+if [ $# -lt 2 ]; then
+    echo "Usage: $0 <device-id> <rtsp-ip> [pem-file]"
+    echo "Example: $0 abc123def456 192.168.2.219 ~/.ssh/id_ed25519_balena"
+    exit 1
+fi
+
+DEVICE_ID="$1"
+RTSP_IP="$2"
+PEM_FILE="$3"
+LOCAL_PORT="${4:-8554}"
+REMOTE_PORT="${5:-554}"
+
+# Check balena CLI
+if ! command -v balena &>/dev/null; then
+    echo "Error: Balena CLI not found"
+    exit 1
+fi
+
+# Check login and get username
+WHOAMI_OUTPUT=$(balena whoami 2>&1)
+if [ $? -ne 0 ]; then
+    echo "$WHOAMI_OUTPUT"
+    exit 1
+fi
+
+USERNAME=$(echo "$WHOAMI_OUTPUT" | grep "USERNAME:" | awk '{print $2}')
+
+# Cleanup function
+cleanup() {
+    echo "Shutting down..."
+    pkill -f "balena device tunnel.*$DEVICE_ID" 2>/dev/null || true
+    pkill -f "ssh.*$USERNAME@localhost.*4321" 2>/dev/null || true
+    exit 0
+}
+trap cleanup SIGINT SIGTERM EXIT
+
+# Start tunnels
+echo "Starting tunnel to $DEVICE_ID..."
+balena device tunnel "$DEVICE_ID" -p 22222:4321 &
+
+sleep 3
+
+# Build SSH command
+SSH_CMD="ssh -N -L $LOCAL_PORT:$RTSP_IP:$REMOTE_PORT $USERNAME@localhost -p 4321 -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
+if [ -n "$PEM_FILE" ]; then
+    SSH_CMD="$SSH_CMD -i $PEM_FILE"
+fi
+
+$SSH_CMD &
+
+echo "Tunnel established successfully from $RTSP_IP:$REMOTE_PORT!"
+echo "RTSP should now be available at localhost:$LOCAL_PORT"
+echo "Example: rtsp://username:password@localhost:$LOCAL_PORT/your-stream-path-here"
+echo "Press Ctrl+C to stop"
+
+# Wait
+wait

src/framegrab/cli/main.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 import click
 
-from . import autodiscover, preview
+from . import autodiscover, balena_rtsp_tunnel, preview
 
 
 @click.group()
@@ -11,6 +11,7 @@ def climain():
 
 
 climain.add_command(autodiscover.autodiscover)
+climain.add_command(balena_rtsp_tunnel.balena_rtsp_tunnel)
 climain.add_command(preview.preview)
 
 if __name__ == "__main__":