docker network

Create and manage the virtual networks containers use to talk to each other by name, and understand the built-in network drivers.

Manage networks

SHELL

1docker network ls # list networks

2docker network create appnet # user-defined bridge network

3docker run -d --name db --network appnet postgres:16

4docker run -d --name api --network appnet -e DB_HOST=db myapi

5docker network connect appnet <container> # attach a running container

6docker network disconnect appnet <container>

7docker network inspect appnet # members and their IPs

8docker network rm appnet

9docker network prune # remove unused networks

Driver	Use it for
`bridge` (default)	Containers on one host. User-defined bridges give automatic DNS by container name
`host`	Container shares the host network stack; no `-p` needed (Linux only)
`none`	No networking at all
`overlay`	Multi-host networking (Swarm)
`macvlan`	Container gets its own MAC/IP on the physical LAN

Containers resolve each other by name only on user-defined networks, not on the default bridge
localhost inside a container means that container, not the host. To reach the host use host.docker.internal (Docker Desktop; on Linux add --add-host=host.docker.internal:host-gateway)
-p is only needed for traffic coming from outside Docker; container-to-container traffic uses the internal port
Compose creates a network per project automatically