MCAP Data Recovery System

Web application for recovering MCAP files from the car and using a shell script that invokes the MCAP CLI to recover the mcap.

Docker Deployment (Linux/Raspberry Pi)

Optimized for Raspberry Pi with 2GB RAM

1. Set the host path to your unrecovered .mcap files in docker-compose.yml:

   volumes:
     - /home/youruser/mcap_logs:/recordings:ro
     - ./mcap_recover:/recordings/mcap_recover.sh:ro

   • Replace /home/youruser/mcap_logs with the folder on your Linux host containing unrecovered .mcap files.
   • Inside the container the app reads from /recordings and runs the script at /recordings/mcap_recover.sh.

2. Build and run:

   docker compose up -d --build

3. Open the app:

   http://localhost:3000
   # Or on Pi: http://<pi-ip>:3000
   

Prerequisites:

• MCAP CLI must be installed on the host system (e.g., /usr/local/bin/mcap)
• Docker will mount the host's mcap binary into the container

Pi Memory Optimization:

• Node.js memory limit set to 1GB (suitable for 2GB Pi)
• Streaming ZIP creation (memory efficient)
• Optimized garbage collection settings

Usage

1. Connect to the car's Wi‑Fi access point.
2. Open a browser to the car's IP on port 3000 (e.g., http://<car-ip>:3000).
3. Select the Files you need to download from car.

How It Works

• The API reads file listings from BASE_DIR (set to /recordings).
• Selected files are copied into a temporary workspace inside the container.
• The recovery script is invoked via sh /recordings/mcap_recover.sh <temp_dir>.
• Recovered files are zipped and returned for download.
• The temporary workspace is removed after completion.

Configuration

Environment variables (already set in docker-compose.yml):

• BASE_DIR=/recordings (do not change unless you also change the volume target)
• SCRIPT_PATH=/recordings/mcap_recover.sh

To change the in-container path, update both the environment values and the volumes target so they match.

Troubleshooting

• No files visible: verify your host path on the left side of the volume mapping contains .mcap files and is readable.
• Script errors: ensure ./mcap_recover exists in the project. The API runs it via sh, so it does not require the executable bit on the host.
• Memory errors on Pi: the app uses streaming ZIP creation and 1GB Node.js memory limit optimized for 2GB Pi RAM.
• Different host path: update the left side of the volume mapping to your desired folder, for example /data/logs:/recordings:ro.
• Pi performance: for better performance, consider using a Pi 4 with 4GB+ RAM or limit file selection to smaller batches.