Docker Deployment

This guide covers running Dalang with Docker Compose for local operations and repeatable team setups.

Quick Start

git clone https://github.com/sangkan-dev/dalang.git
cd dalang

cat > .env << 'EOF'
LLM_PROVIDER=openai
LLM_API_KEY=your-api-key-here
# Optional:
# LLM_BASE_URL=https://your-endpoint.example.com/v1
EOF

docker compose up --build

Dalang web UI is available at http://localhost:4000.

Service Overview

The default docker-compose.yml runs one service:

• dalang container built from the repository Dockerfile
• startup command: dalang web --port 4000
• host networking enabled (network_mode: host)
• persistent data volume: dalang_data:/root/.dalang

Environment Variables

Set values in .env or your shell before startup:

• LLM_PROVIDER (default: openai)
• LLM_API_KEY (required)
• LLM_BASE_URL (optional, for OpenAI-compatible endpoints)

Example:

LLM_PROVIDER=openai
LLM_API_KEY=sk-...
LLM_BASE_URL=

Lifecycle Commands

# Build and start in foreground
docker compose up --build

# Start in background
docker compose up -d --build

# Stream logs
docker compose logs -f dalang

# Stop services
docker compose down

# Stop and remove named volumes
docker compose down -v

Persistence

Dalang stores sessions, memory snapshots, and runtime artifacts under /root/.dalang in the container. With the default compose file this path is backed by a named volume (dalang_data) so state survives container restarts.

Networking Notes

The default configuration uses network_mode: host for maximum compatibility with local/LAN scans.

Tradeoffs:

• Pros: simpler reachability to host-local services and private network targets
• Cons: no port publishing isolation; service binds directly to host namespace

If your environment requires stricter isolation, switch to bridge networking and publish only required ports (for example 4000:4000).

Tooling Included in the Image

The Docker image includes Dalang plus a broad built-in tooling stack (for example nmap, sqlmap, nikto, hydra, masscan, rustscan, subfinder, httpx, nuclei, ffuf, and more).

This avoids manual per-host tool installation for most common workflows.

Customization

Common extension points:

• Add or pin extra tools in Dockerfile
• Override startup command in docker-compose.yml
• Mount additional host paths if your workflow requires custom wordlists or artifacts

Troubleshooting

Container starts but UI is unreachable

• Check logs: docker compose logs -f dalang
• Ensure nothing else is already using port 4000
• Verify your firewall allows local access to the port

LLM requests fail

• Confirm .env has correct LLM_PROVIDER and LLM_API_KEY
• If using custom endpoints, validate LLM_BASE_URL
• Restart after config changes: docker compose up -d --build

Sessions disappear after restart

• Verify dalang_data volume exists: docker volume ls | grep dalang_data
• Confirm compose service still mounts dalang_data:/root/.dalang

Missing tool error during execution

• Check tool presence inside container: docker compose exec dalang which nmap
• Rebuild image if Dockerfile changed: docker compose up --build