Docker Network Configuration

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

# Create network with specific subnet
docker network create \
  --driver bridge \
  --subnet 172.20.0.0/16 \
  --gateway 172.20.0.1 \
  app-network

# Run containers on the same network
docker run -d --name api --network app-network myapp:latest
docker run -d --name db --network app-network postgres:16

# Containers can now resolve each other by name:
# From api container: postgres://db:5432/mydb

# Connect existing container to a network
docker network connect app-network existing-container

# Disconnect from a network
docker network disconnect bridge existing-container

# Inspect network details
docker network inspect app-network

# List all networks
docker network ls

# Remove unused networks
docker network prune

# docker-compose.yml with multiple networks
# services:
#   api:
#     networks: [frontend, backend]
#   db:
#     networks: [backend]
#   nginx:
#     networks: [frontend]
# networks:
#   frontend:
#   backend:
#     internal: true  # no external access