Docker networks

Intermediate Docker

Mike Metzger

Data Engineering Consultant

Docker networking

Docker has extensive networking options
Can create networks to communicate between containers, host, and external systems
Will cover various commands to interact with networks.

Docker networking types

Docker supports different networking types, using drivers
- bridge: Default driver, allows connections out, connections in if exposed
- host: Allows full communication between host and containers
- none: Isolate container from network communications
- Many others, including custom drivers
Will mostly use the bridge driver to create our own networks

Working with Docker networks

Several commands:

docker network
- docker network <command>
- docker network <command> --help
- docker network ls to list all docker networks on the host
- docker network create to create a network
- docker network rm to remove a network

Docker network example

Create a Docker network named mynetwork

repl@host:~$ docker network create mynetwork

5ff0febab98f73b74dd753eb44a30f7d7291052b3b1d58b0134589221cb8e33d

repl@host:~$ docker network ls

NETWORK ID     NAME        DRIVER    SCOPE
2edc5ae4838c   bridge      bridge    local
a92988382711   host        host      local
5ff0febab98f   mynetwork   bridge    local
5464ed866dad   none        null      local

Attaching containers to networks

How to connect container to a network?
docker run --network <networkname> ...
docker run --network mynetwork ubuntu bash

Can also connect containers later
- docker network connect <networkname> <container>
- docker network connect mynetwork ubuntu-B

docker network inspect

How to check details of network?
docker network inspect <networkname>
Provides configuration info and IP addresses assigned to containers
```
repl@host:~$ docker network inspect mynetwork
```

docker network inspect example

        "Name": "mynetwork",
        ...
        "Driver": "bridge",
        ...
        Containers": {    "2be08aa942029191350d4bceb8816254af8713dd6f7dcbadcab8f068f7dbfdfa": {
                "Name": "unruffled_kare",
                "EndpointID": "29739356ae200e1e901d2eabef05efaca0fb37e1a4e1a4c3bf369f2892ca6c4b",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": ""
            }

Let's practice!

Intermediate Docker