README
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Weave Net - Weaving Containers into Applications
About Weaveworks
Weaveworks is the company that delivers the most productive way for developers to connect, observe and control Docker containers. The first product developed by Weaveworks, with nearly 5 million downloads to date, is Weave Net, enabling users to get started with Docker clusters and portable apps in a fraction of the time compared to other solutions. In addition, Weaveworks offers Weave Scope, a powerful container monitoring tool that automatically maps Docker containers and their interactions, as well as Weave Flux, a microservice router that automates the access of containers as services.
Introduction
This document is intended to cover some of the more technical aspects of Weave Net. To learn about our products, including getting started tutorials, visit our website and documentation.
Weave Net
Weave Net creates a virtual network that connects Docker containers deployed across multiple hosts and enables their automatic discovery.
Applications use the network just as if the containers were all plugged into the same network switch, with no need to configure port mappings, links, etc. Services provided by application containers on the weave network can be made accessible to the outside world, regardless of where those containers are running. Similarly, existing internal systems can be exposed to application containers irrespective of their location.
Weave Net can traverse firewalls and operate in partially connected networks. Traffic can be encrypted, allowing hosts to be connected across an untrusted network.
With Weave Net you can easily construct applications consisting of multiple containers, running anywhere.
Weave Net works alongside Docker's existing (single host) networking capabilities, so these can continue to be used by containers.
Installation
To get started, you should be running Linux (kernel 3.8 or later) and have Docker (version 1.6.0 or later) installed. Then install Weave Net with
sudo curl -L git.io/weave -o /usr/local/bin/weave
sudo chmod a+x /usr/local/bin/weave
For usage on OSX (with Docker Machine) you first need to make sure that a VM is running and configured. Then you can launch Weave Net directly from the OSX host.
For installing Weave Net on other platforms, follow the integration guides.
Weave Net respects the environment variable DOCKER_HOST, so you can run
it locally to control a weave network on a remote host.
Weave Net periodically contacts Weaveworks servers for available versions. New versions are announced in the log and in the status summary. To disable this check, run:
export CHECKPOINT_DISABLE=1
before launching Weave Net.
Quick Start Screencast
Example
Say you have docker running on two hosts, accessible to each other as
$HOST1 and $HOST2, and want to deploy an application consisting of
two containers, one on each host.
On $HOST1 you would run:
host1$ weave launch
host1$ eval $(weave env)
host1$ docker run --name a1 -ti ubuntu
NB: If the first command results in an error like
http:///var/run/docker.sock/v1.19/containers/create: dial unix /var/run/docker.sock: permission denied. Are you trying to connect to a TLS-enabled daemon without TLS?then you likely need to be 'root' in order to connect to the Docker daemon. If so, run the above and all subsequent commands in a single root shell (e.g. one created withsudo -s). Do not prefix individual commands withsudo, since some commands modify environment entries and hence they all need to be executed from the same shell.
The first line runs Weave Net. The second line configures your environment so that containers launched via the docker command line are automatically attached to the weave network. Finally, you run your application container.
That's it! If your application consists of more than one container on
this host, you can simply launch them with docker run as appropriate.
Next you'll repeat similar steps on $HOST2...
host2$ weave launch $HOST1
host2$ eval $(weave env)
host2$ docker run --name a2 -ti ubuntu
The only difference, apart from the name of the application container,
is that weave is being told that it should peer with the weave on
$HOST1 (specified as the IP address or hostname, and optional
:port, by which $HOST2 can reach it). NB: if there is a firewall
between $HOST1 and $HOST2, you must permit traffic to the weave
control port (TCP 6783) and data ports (UDP 6783/6784).
Note that you could instead have told the Weave Net instance on $HOST1 to connect to
$HOST2, or told both about each other. Order does not matter here;
Weave Net automatically (re)connects to peers when they become
available. You can instruct Weave Net to connect to multiple peers by
supplying multiple addresses, separated by spaces; you can also
add peers dynamically.
Weave Net must be started once per host. The relevant container images are
pulled down on demand, but if you wish you can preload them by running
weave setup - this is particularly useful for automated deployments,
and ensures that there are no delays during later operations.
Now that you've got everything set up, let's confirm that your containers can talk to each other...
In the container started on $HOST1...
root@a1:/# ping -c 1 -q a2
PING a2.weave.local (10.40.0.2) 56(84) bytes of data.
--- a2.weave.local ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.341/0.341/0.341/0.000 ms
Similarly, in the container started on $HOST2...
root@a2:/# ping -c 1 -q a1
PING a1.weave.local (10.32.0.2) 56(84) bytes of data.
--- a1.weave.local ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.366/0.366/0.366/0.000 ms
So there you have it, two containers on separate hosts happily talking to each other.
Find out more
Contact Us
Found a bug, want to suggest a feature, or have a question? Please
file an issue, or post
to the
Weave Users Google Group,
which you can email at weave-users@weave.works. When reporting a bug, please
include which version of Weave Net you are running, as shown by weave version.
Follow us on Twitter: @weaveworks.
Check out our blog for the latest product and ecosystem news: Weaveworks Blog.
IRC: #weavenetwork
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