4.3 KiB
Overlay Driver
Design
TODO
Multi-Host Overlay Driver Quick Start
This example is to provision two Docker Hosts with the experimental Libnetwork overlay network driver.
Pre-Requisites
- Kernel >= 3.16
- Experimental Docker client
Install Docker Experimental
Follow Docker experimental installation instructions at: https://github.com/docker/docker/tree/master/experimental
To ensure you are running the experimental Docker branch, check the version and look for the experimental tag:
$ docker -v
Docker version 1.8.0-dev, build f39b9a0, experimental
Install and Bootstrap K/V Store
Multi-host networking uses a pluggable Key-Value store backend to distribute states using libkv.
libkv supports multiple pluggable backends such as consul, etcd & zookeeper (more to come).
In this example we will use consul
Install:
$ curl -OL https://dl.bintray.com/mitchellh/consul/0.5.2_linux_amd64.zip
$ unzip 0.5.2_linux_amd64.zip
$ mv consul /usr/local/bin/
host-1 Start Consul as a server in bootstrap mode:
$ consul agent -server -bootstrap -data-dir /tmp/consul -bind=<host-1-ip-address>
host-2 Start the Consul agent:
$ consul agent -data-dir /tmp/consul -bind=<host-2-ip-address>
$ consul join <host-1-ip-address>
Start the Docker Daemon with the Network Driver Daemon Flags
host-1 Docker daemon:
$ docker -d --kv-store=consul:localhost:8500 --label=com.docker.network.driver.overlay.bind_interface=eth0
host-2 Start the Docker Daemon with the neighbor ID configuration:
$ docker -d --kv-store=consul:localhost:8500 --label=com.docker.network.driver.overlay.bind_interface=eth0 --label=com.docker.network.driver.overlay.neighbor_ip=<host-1-ip-address>
QuickStart Containers Attached to a Network
host-1 Start a container that publishes a service svc1 in the network dev that is managed by overlay driver.
$ docker run -i -t --publish-service=svc1.dev.overlay debian
root@21578ff721a9:/# ip add show eth0
34: eth0: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:ec:41:35:bf brd ff:ff:ff:ff:ff:ff
inet 172.21.0.16/16 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::42:ecff:fe41:35bf/64 scope link
valid_lft forever preferred_lft forever
host-2 Start a container that publishes a service svc2 in the network dev that is managed by overlay driver.
$ docker run -i -t --publish-service=svc2.dev.overlay debian
root@d217828eb876:/# ping svc1
PING svc1 (172.21.0.16): 56 data bytes
64 bytes from 172.21.0.16: icmp_seq=0 ttl=64 time=0.706 ms
64 bytes from 172.21.0.16: icmp_seq=1 ttl=64 time=0.687 ms
64 bytes from 172.21.0.16: icmp_seq=2 ttl=64 time=0.841 ms
Detailed Setup
You can also setup networks and services and then attach a running container to them.
host-1:
docker network create -d overlay prod
docker network ls
docker network info prod
docker service publish db1.prod
cid=$(docker run -itd -p 8000:8000 ubuntu)
docker service attach $cid db1.prod
host-2:
docker network ls
docker network info prod
docker service publish db2.prod
cid=$(docker run -itd -p 8000:8000 ubuntu)
docker service attach $cid db2.prod
Once a container is started, a container on host-1 and host-2 both containers should be able to ping one another via IP, service name, <service name>.<network name>
View information about the networks and services using ls and info subcommands like so:
$ docker service ls
SERVICE ID NAME NETWORK CONTAINER
0771deb5f84b db2 prod 0e54a527f22c
aea23b224acf db1 prod 4b0a309ca311
$ docker network info prod
Network Id: 5ac68be2518959b48ad102e9ec3d8f42fb2ec72056aa9592eb5abd0252203012
Name: prod
Type: overlay
$ docker service info db1.prod
Service Id: aea23b224acfd2da9b893870e0d632499188a1a4b3881515ba042928a9d3f465
Name: db1
Network: prod
To detach and unpublish a service:
$ docker service detach $cid <service>.<network>
$ docker service unpublish <service>.<network>
# Example:
$ docker service detach $cid db2.prod
$ docker service unpublish db2.prod
To reiterate, this is experimental, and will be under active development.