# Weave - weaving containers into applications [![Build Status](https://travis-ci.org/weaveworks/weave.svg?branch=master)](https://travis-ci.org/weaveworks/weave) [![Integration Tests](https://circleci.com/gh/weaveworks/weave/tree/master.svg?style=shield&circle-token=4933c7dabb3d0383e62117565cb9d16df7b1a811)](https://circleci.com/gh/weaveworks/weave) [![Coverage Status](https://coveralls.io/repos/weaveworks/weave/badge.svg)](https://coveralls.io/r/weaveworks/weave) Weave creates a virtual network that connects Docker containers deployed across multiple hosts and enables their automatic discovery. ![Weave Virtual Network](/docs/virtual-network.png?raw=true "Weave Virtual Network") 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 Deployment](/docs/deployment.png?raw=true "Weave Deployment") Weave can traverse firewalls and operate in partially connected networks. Traffic can be encrypted, allowing hosts to be connected across an untrusted network. With weave you can easily construct applications consisting of multiple containers, running anywhere. Weave works alongside Docker's existing (single host) networking capabilities, so these can continue to be used by containers. ## Installation Ensure you are running Linux (kernel 3.8 or later) and have Docker (version 1.3.1 or later) installed. Then install weave with sudo wget -O /usr/local/bin/weave \ https://github.com/weaveworks/weave/releases/download/latest_release/weave sudo chmod a+x /usr/local/bin/weave CoreOS users see [here](https://github.com/fintanr/weave-gs/blob/master/coreos-simple/user-data) for an example of installing weave using cloud-config. Weave respects the environment variable `DOCKER_HOST`, so you can run it locally to control a weave network on a remote host. ## 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 `$HOST1` run host1$ weave launch host1$ C=$(weave run 10.2.1.1/24 -t -i ubuntu) The first line starts the weave router, in a container. This needs to be done once on each host. The required docker image for the weave router container is downloaded automatically. There is also a `weave setup` command for downloading this and other images required for weave operation; this is a strictly optional step which is especially useful for automated installation of weave and ensures that any subsequent weave commands do not encounter delays due to image downloading. The second line runs our application container. We give it an IP address and network, in [CIDR notation](http://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation). `weave run` invokes `docker run -d` with all the parameters following the IP address and network. So we could be launching any container this way; here we just take a stock ubuntu container and launch a shell in it. There's also a `weave start` command, which invokes `docker start` for starting existing containers. If our application consists of more than one container on this host we simply launch them with a variation on that second line. The IP addresses and netmasks can be anything you like, but make sure they don't conflict with any IP ranges in use on the hosts or IP addresses of external services the hosts or containers need to connect to. The same IP range must be used everywhere, and the individual IP addresses must, of course, be unique. We repeat similar steps on `$HOST2`... host2$ weave launch $HOST1 host2$ C=$(weave run 10.2.1.2/24 -t -i ubuntu) The only difference, apart from the choice of IP address for the application container, is that we tell our weave that it should peer with the weave on `$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 `$HOST2`, you must open the weave port (6783 by default; this can be overriden by setting `WEAVE_PORT`) for TCP and UDP. Note that we could instead have told the weave on `$HOST1` to connect to `$HOST2`, or told both about each other. Order does not matter here; weave automatically (re)connects to peers when they become available. Also, we can tell weave to connect to multiple peers by supplying multiple addresses, separated by spaces. And we can [add peers dynamically](http://docs.weave.works/weave/latest_release/features.html#dynamic-topologies). Now that we've got everything set up, let's see whether our containers can talk to each other... On `$HOST1`... host1$ docker attach $C root@28841bd02eff:/# ping -c 1 -q 10.2.1.2 PING 10.2.1.2 (10.2.1.2): 48 data bytes --- 10.2.1.2 ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.048/1.048/1.048/0.000 ms Similarly, on `$HOST2`... host2$ docker attach $C root@f76829496120:/# ping -c 1 -q 10.2.1.1 PING 10.2.1.1 (10.2.1.1): 48 data bytes --- 10.2.1.1 ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.034/1.034/1.034/0.000 ms So there we have it, two containers on separate hosts happily talking to each other. ## Find out more * [Documentation homepage](http://docs.weave.works/weave/latest_release/) * [Features](http://docs.weave.works/weave/latest_release/features.html) * [Automatic Discovery with WeaveDNS](http://docs.weave.works/weave/latest_release/weavedns.html) * [Troubleshooting](http://docs.weave.works/weave/latest_release/troubleshooting.html) * [Building](http://docs.weave.works/weave/latest_release/building.html) * [How it works](http://docs.weave.works/weave/latest_release/how-it-works.html) ## Contact Us Found a bug, want to suggest a feature, or have a question? [File an issue](https://github.com/weaveworks/weave/issues), or email help@weave.works. When reporting a bug, please include which version of weave you are running, as shown by `weave version`. Follow weave on Twitter: [@weaveworks](https://twitter.com/weaveworks). Read the Weave blog: [Weaveblog](http://weaveblog.com/). IRC: [#weavenetwork](https://botbot.me/freenode/weavenetwork/)