Docker Networking

Docker NetworkingJohn Merrells

DockerThe current state of Docker Networking

get a server

Ubuntu 14.04

eth0: 45.79.82.5

install an operating system

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1

install Docker

Docker 1.6.2

$ wget -qO- https://get.docker.com/ | sh

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1veth7b4d22b

start a container

eth0: 172.17.0.1port: 5000

$ docker run -d …

Ubuntu 14.04


traffic routed through docker bridge

eth0: 172.17.0.1port: 5000

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1veth7b4d22bport 32768

start a container, and publish a port

$ docker run -d -P …

eth0: 172.17.0.1port: 5000

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1veth7b4d22bport 32768

traffic to port forwarded

eth0: 172.17.0.1port: 5000

Ubuntu 14.04

If we want containers to communicate with each other

eth0: 45.79.82.5docker0: 172.17.42.1

Ubuntu 14.04


start a container, with a name

$ docker run -d —name web …

eth0: 172.17.0.1port: 5000name: web

Ubuntu 14.04

start containers with names, and ‘link’ them together

eth0: 172.17.0.1port: 5432name: db


eth0: 45.79.82.5docker0: 172.17.42.1veth8a5c43aveth7b4d22bport 32768

$ docker run -d --name db … $ docker run -d -P --name web --link db:db …

Ubuntu 14.04

eth0: 172.17.0.1port: 5432name: db

eth0: 172.17.0.2port: 5000name: webDB_PORT=tcp://172.17.0.7:5432DB_PORT_5432_TCP=tcp://172.17.0.7:5432DB_PORT_5432_TCP_ADDR=172.17.0.7DB_PORT_5432_TCP_PORT=5432DB_PORT_5432_TCP_PROTO=tcpDB_NAME=/web/db

linking is via environment variables

custom application code needed

h2eth0: 45.79.90.4docker0: 172.17.42.1

h1eth0: 45.79.82.5docker0: 172.17.42.1

If we want containers, on different hosts,

to communicate with each other

Docker hosts don’t know about each other

eth0: 172.17.0.1port: 5432name: db

h2eth0: 45.79.90.4docker0: 172.17.42.1port 32768


h1eth0: 45.79.82.5docker0: 172.17.42.1port 32893

there’s no linking across the network

h1$ docker run -d -P —name web … h2$ docker run -d -P —name db …

Container NetworkingDocker

IP Allocation Subnet per Host

Routing NAT

Ports IPTables, Port Forwarding, Random Ports

Service Discovery Environment Variables

Multi Host Not Supported

WeaveNetworking with Docker + Weave

get a server

Ubuntu 14.04

eth0: 45.79.82.5

install an operating system

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1

install Docker

Docker 1.6.2

$ wget -qO- https://get.docker.com/ | sh

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1

install Weave

Docker 1.6.2

$ wget -O /usr/local/bin/weave \ https://git.io/weave

Weave 0.10.0

https://git.io/weave

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1vethace68bd

weavevethwepl8289

launch the weave router

$ weave launch

eth0: 10.0.0.1name: weaveport: 6783

Ubuntu 14.04

eth0: 45.79.82.5docker0: 172.17.42.1vethace68bd

weavevethwepl8289


let’s ignore the docker bridge and interfaces

eth0: 45.79.82.5

weavevethwepl8289

vethwepl8709

start a container

$ weave run 10.2.1.1/24 -d …


eth0: 10.2.1.1port: 5000

eth0: 45.79.82.5

weavevethwepl8289

vethwepl8709

traffic routed through weave


eth0: 10.2.1.1port: 5000

eth0: 45.79.82.5

weavevethwepl8289

vethwepl8709

start a container, publish a port

$ weave run 10.2.1.1/24 -d —name web -p 5000:5000 …



eth0: 45.79.82.5

weavevethwepl8289

vethwepl8709

traffic router through weave, no random port



eth0: 45.79.82.5

weave

If we want containers to communicate with each other


eth0: 45.79.82.5

weave

use the weave DNS server

$ weave launch-dns 10.1.0.3/16 …

eth0: 10.0.0.1name: weaveport: 6783eth0: 10.1.0.3name: weavednsport: 53

eth0: 45.79.82.5

weavevethwepl8289

vethwepl8801

vethwepl8709eth0: 10.2.1.1port: 5000name: web

eth0: 10.2.1.2port: 5432name: db

$ weave run 10.2.1.1/24 -d —name web -p 5000:5000 … $ weave run 10.2.1.2/24 -d —name db …

now we can name containers

eth0: 10.0.0.1name: weaveport: 6783eth0: 10.1.0.3name: weavednsport: 53

and they can find each other with regular DNS lookups

name: weaveport: 6783

name: weavednsport: 53

eth0: 10.2.1.1port: 5000name: webfqdn: web.weave.local

eth0: 10.2.1.2port: 5432name: dbfqdn: db.weave.local

eth0: 45.79.82.5

weavevethwepl8289

vethwepl8801

vethwepl8709

Where’s db?

Where’s web?

and communicate with each other over regular IP based protocols

name: weaveport: 6783




eth0: 45.79.82.5

weavevethwepl8289

vethwepl8801

vethwepl8709

h2eth0: 45.79.90.4

h1eth0: 45.79.82.5

eth0: 10.0.0.2name: weaveport: 6783peer: 45.79.82.5




h1$ weave launch 10.0.0.1/16 h2$ weave launch 10.0.0.2/16 45.79.82.5

If we want containers, on different hosts,

to communicate with each other

h2eth0: 45.79.90.4

h1eth0: 45.79.82.5


name: weavednsport: 53eth0: 10.2.1.1port: 5000name: webfqdn: web.weave.local


h1$ weave run 10.2.1.1/24 -d —name web -p 5000:5000 … h2$ weave run 10.2.1.2/24 -d —name db …

It’s just the same, containers can find each other with DNS



Where’s db?

Where’s web?

h2eth0: 45.79.90.4

h1eth0: 45.79.82.5




and can communicate over regular IP based protocols



Container NetworkingDocker Weave

IP Allocation Subnet per Host Subnet per App

Routing NAT L2 Routing

Ports IPTables As they should be

Service Discovery Environment Variables DNS

Multi Host Not Supported Supported

WeaveBut wait, there’s more…

mesh of peers, that gossip with each other

eth0: 10.2.1.2 eth0: 10.2.1.3

eth0: 10.2.1.4eth0: 10.2.1.1

eth0: 10.2.1.2 eth0: 10.2.1.3

eth0: 10.2.1.4eth0: 10.2.1.1

mesh of peers, with least cost routing

start containers, on different clouds…

Weave 0.10.0

eth0: 10.2.1.2 eth0: 10.2.1.3 eth0: 10.2.1.4eth0: 10.2.1.1

encrypted traffic for application isolation

eth0: 10.2.1.2eth0: 10.2.1.1 eth0: 10.2.1.2eth0: 10.2.1.1

$ weave launch -password secret123

$ weave launch -password 321terces

h2eth0: 45.79.90.4

h1eth0: 45.79.82.5



containers can migrate, from host to host



h2eth0: 45.79.90.4

h1eth0: 45.79.82.5




containers can migrate, and maintain the same IP Address



WeaveAnd coming soon

eth0: 45.79.82.5

fast data path


eth0: 10.2.1.1port: 5000

OVS kernel

module

eth0: 45.79.82.5

weave

IP Address Management

eth0: 10.0.0.1name: weaveport: 6783iprange: 10.0.0.1/16

$ weave launch -iprange 10.0.0.1/16 $ weave run -d …

eth0: 10.0.0.2

Scope

Weave Scope

John [email protected]

mailto:[email protected]

Technology

Docker Networking