Slides describing Docker Networking basics and experiments showing how to connect docker containers across 2 hosts

1. Docker Networking
Intro Meetup
Sriram Natarajan
Dhananjay Sampath

2. Agenda
Introduction to Container Networking
Docker + OpenvSwitch demo
Hands on Tutorial instructions

3. Docker Networking 101
eth0
docker0
172.17.42.1
Container1 Container2
eth0 eth0
vethAQI2T veth01qe

4. Docker Bridge options
--net=bridge
--net=host
--net=container:NAME_or_ID
--net=none

5. --net=None

6. Port Mapping
eth0
docker0
172.17.42.1:49514
Container1 Container2
eth0:5000 eth0
vethAQI2T veth01qe
-P flag

7. Internet Communication
eth0
docker0
172.17.42.1
internet
Container1 Container2
eth0 eth0
vethAQI2T veth01qe
ip_forward = 1

8. Inter Container Communication
Container2
eth0
vethAQI2T veth01qe
docker0
Container1
--icc=true

9. Linking of Containers
● Name the container using --name option
● Link container using --link name:alias
db
eth0
vethAQI2T veth01qe
docker0
web

10. Hands on setup instructions
Containet Source Code: https://bitbucket.org/snrism/containet
Instructions: README part of the source code.

11. Connecting docker containers in 2 hosts
Container 1 Container 2
172.17.0.4 172.17.0.5
docker0
Container 3 Container 4
172.17.0.4 172.17.0.5
docker0
172.17.42.1 172.17.42.1
Host 1 Host 2
eth1 eth1
10.0.0.3 10.0.0.4
IP Address Conflicts…

12. Configuring container IP addresses
Container 1 Container 2
172.18.42.10 172.18.42.11
docker0
Container 3 Container 4
172.18.42.12 172.18.42.13
docker0
172.18.42.1 172.18.42.2
Host 1 Host 2
eth1 eth1
10.0.0.3 10.0.0.4
Start a container w/o using docker's default network config: docker run -d --net=none -t -i ubuntu /bin/bash
Record the Container ID that just started: docker ps
Configure IP addresses on eth0: ./start-container.sh <container-id> <ip-addr>

13. Experiment 1
Connect hosts via OVS (docker bridge + OVS)
Container 1 Container 2
172.18.42.10 172.18.42.11
docker0
Container 3 Container 4
172.18.42.12 172.18.42.13
docker0
br0
(ovs) gre0
br0
g r e 0 (ovs)
172.18.42.1 172.18.42.2
Host 1 Host 2
eth1 eth1
10.0.0.3 10.0.0.4
Setup GRE Tunnel: ./ovs-tunnel-setup.sh
Setup IPTables for containers to reach other hosts: ./iptables.sh
Start a container w/o using docker's default network config: docker run -d --net=none -t -i ubuntu /bin/bash
Record the Container ID that just started: docker ps
Configure IP addresses on eth0: ./start-container.sh <container-id> <ip-addr>

14. Experiment 2
Connect hosts via OVS (direct OVS)
Container 1 Container 2 Container 3 Container 4
br0
(ovs) gre0
br0
g r e 0 (ovs)
Host 1 Host 2
eth1 eth1
10.0.0.3 10.0.0.4
Start a container w/o using docker's default network config: docker run -d --net=none -t -i ubuntu /bin/bash
Record the Container ID that just started: docker ps
Configure eth1 and attach to OVS: ./connect-container.sh <container-id> <ip-addr>

15. Experiment 3
Connect hosts via OVS (direct OVS)
Use VLAN tags to segregate containers
Container 1 Container 2 Container 3 Container 4
br0
(ovs) gre0
br0
g r e 0 (ovs)
Host 1 Host 2
eth1 eth1
Start a container w/o usi1n0g.0 d.0o.3cker's default network config: docker run -d1 0--.n0.e0t.4=none -t -i ubuntu /bin/bash
Record the Container ID that just started: docker ps
Configure eth1 and attach to OVS: ./connect-container.sh <container-id> <ip-addr> <vlan-tag>

16. Advanced Tools
Open Source Tools Description
Pipework
https://github.com/jpetazzo/pipework
Better configuration capabilities.
Works well with LXC and docker
Weave
https://github.com/zettio/weave
Simplifies connecting containers across multiple hosts.
Lorispack
https://github.com/lorispack/loris
Heterogeneous options to connect containers across hosts
Kubernetes
https://github.
com/GoogleCloudPlatform/kubernetes
Container cluster manager
Flannel
https://github.com/coreos/flannel
Overlay network that gives subnet for each machine with kubernetes
Openstack Icehouse – Orchestrate docker containers via heat templates