Bits of .NET

🌐 Docker Networking = Container Communication

Containers need to communicate. Docker networks connect containers. Bridge, host, overlay — choose right network.

📝 Network Types

# Bridge (default)
docker network create my-bridge
docker run --network my-bridge app

# Host (use host network)
docker run --network host app

# None (isolated)
docker run --network none app

# Overlay (multi-host)
docker network create -d overlay my-overlay

# Macvlan (direct access)
docker network create -d macvlan \
    --subnet=192.168.1.0/24 \
    --gateway=192.168.1.1 \
    -o parent=eth0 my-macvlan

# View networks
docker network ls

# Inspect network
docker network inspect bridge

# Remove network
docker network rm my-network

🎯 Network Commands

# Create custom bridge
docker network create --driver bridge my-app-network

# Run with custom network
docker run -d --name web --network my-app-network nginx
docker run -d --name db --network my-app-network postgres

# Connect containers
docker network connect my-app-network container-name

# Disconnect container
docker network disconnect my-app-network container-name

# Port mapping
docker run -p 8080:80 --network my-app-network nginx

# Docker Compose
version: '3.8'
services:
    web:
        networks:
            - frontend
            - backend
    
    db:
        networks:
            - backend

networks:
    frontend:
        driver: bridge
    backend:
        driver: bridge

# Container DNS
# Containers can reach by service name
# web -> db (resolves to db container)

# Network Tips
- Use custom networks for isolation
- Containers in same network can communicate
- Use service name for DNS
- Bridge network for single host
- Overlay for multi-host

💡 Network Tips

• Use custom networks for isolation
• Containers in same network can communicate
• Use service name for DNS
• Bridge network for single host
• Overlay for multi-host