Integrating Docker via the Network Plugin (V2)

Installation
Configuring the Plugin
Running Services or Containers Using the Plugin

Docker Engine version 1.12 introduced a new plugin system (V2). This document describes how to use the Network Plugin V2 of Weave Net.

Before using the plugin, please keep in mind the plugin works only in Swarm mode and requires Docker version 1.13 or later.

Installation

To install the plugin run the following command on each host already participating in a Swarm cluster, i.e. on all master and worker nodes:

$ docker plugin install rajchaudhuri/net-plugin:latest_release-<architecture>

Here, <architecture> is the processor architecture on which your Docker Engine runs. It is a necessary part of the plugin name, because Docker currently does not support multi-architecture plugins. The Weave Net Plugin V2 is available for the following architectures:

amd64
arm
arm64
~~ppc64le~~
~~s390x~~

You can use the following commands to install the plugin appropriate to your architecture:

$ ARCH=$(docker version -f '{{.Server.Arch}}')
$ docker plugin install rajchaudhuri/net-plugin:latest_release-$ARCH

Docker will pull the plugin from Docker Store, and it will ask to grant privileges before installing the plugin. Afterwards, it will start weaver process which will try to connect to Swarm masters running Weave Net.

Configuring the Plugin

There are several configuration parameters which can be set with:

$ docker plugin set rajchaudhuri/net-plugin:latest_release-$ARCH PARAM=VALUE

The parameters include:

WEAVE_PASSWORD - if non empty, it will instruct Weave Net to encrypt traffic - see here for more details.
WEAVE_MULTICAST - set to 1 on each host running the plugin to enable multicast traffic on any Weave Net network.
WEAVE_MTU - Weave Net defaults to 1376 bytes, but you can set a smaller size if your underlying network has a tighter limit, or set a larger size for better performance if your network supports jumbo frames - see here for more details.
IPALLOC_RANGE - the range of IP addresses used by Weave Net and the subnet they are placed in (CIDR format; default 10.32.0.0/12). See here for more details.

Before setting any parameter, the plugin has to be disabled with:

$ docker plugin disable rajchaudhuri/net-plugin:latest_release-$ARCH

To re-enable the plugin run the following command:

$ docker plugin enable rajchaudhuri/net-plugin:latest_release-$ARCH

Running Services or Containers Using the Plugin

After you have launched the plugin, you can create a network for Docker Swarm services by running the following command on any Docker Swarm master node:

$ docker network create --driver=rajchaudhuri/net-plugin:latest_release-$ARCH mynetwork

Or you can create a network for any Docker container with:

$ docker network create --driver=rajchaudhuri/net-plugin:latest_release-$ARCH --attachable mynetwork

To start a service attached to the network run, for example:

$ docker service create --network=mynetwork ...

To ensure that name resolution (service discovery) works as expected, do one of the following:

Include --endpoint-mode=dnsrr while creating a service. This will correctly resolve the service name to the load-balanced IP address of one of the task containers.
OR, include --hostname=SOMENAME while creating a servce. This will also resolve SOMENAME to the load-balanced IP address of one of the task containers.

To start a container:

$ docker run --network=mynetwork ...

This does not require a --hostname option. The container name and any network aliases will correctly resolve to the container’s IP address.

See Also