Troubleshooting and FAQ

Troubleshooting & FAQ

This page addresses common environment issues, kernel configurations, and networking errors encountered while using Damru.

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🕸️ Network & DNS Resolution Failures

Symptom: net::ERR_NAME_NOT_RESOLVED or No Internet Inside Containers

• Cause: On some hosts (especially WSL2 and VPS servers), Docker's NAT or forwarding rules are blocked by custom firewall chains.
• Fix: Run the automated network repair command:

  python -m damru fix-internet

  This command installs correct MASQUERADE and FORWARD rules on the docker0 bridge.
• Manual Verification: Run a quick connectivity check:

  docker run --rm alpine ping -c 3 google.com

  If this fails, ensure the host DNS resolver /etc/resolv.conf is accessible by Docker.

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🐧 Kernel Module & Binderfs Errors

Symptom: Failed to open /dev/binder or /dev/binderfs/binder-control: No such file

• Cause: The host kernel lacks the binder/binderfs modules required for Redroid container inter-process communication.
• Fix (WSL2): Switch to Damru's pre-compiled WSL2 kernel:
  1. Download our kernel and place it at C:\Users\<User>\vmlinux.
  2. Add the path to .wslconfig and run wsl --shutdown.
• Fix (Native Linux): Load the kernel modules manually:

  sudo modprobe ashmem_linux
  sudo modprobe binder_linux devices="binder,vndbinder,hwbinder"

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⚖️ Port Bindings & Docker Conflicts

Symptom: Address already in use or Port Conflicts during Pool allocation

• Cause: Multiple worker pools or other processes are running on the default ADB ports (5600+).
• Fix: remap the default starting port using the environment variable:

  export DAMRU_REDROID_BASE_PORT=5700

  This offsets all running workers to ports 5700, 5701, etc., avoiding port collision.

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❓ Frequently Asked Questions

Q: Can I run Damru on a headless VPS?
A: Yes. Damru is optimized for headless VPS deployments (e.g. Ubuntu 24.04). All render pipelines run virtualized.

Q: How do I visually inspect what Chrome is doing in the container?
A: Ensure you have scrcpy installed, then run the live-view CLI command:

python -m damru view --serial <adb_serial>

This mirrors the Android screen onto your local machine in real-time.