3.1 KiB
title, layout
| title | layout |
|---|---|
| Weave Proxy | default |
Weave Proxy
Instead of the weave command-line utility, you may prefer to use the standard docker command-line utility to manage containers. This will allow containers to be started in foreground mode. It will also ensure that the weave network interface is available before running your container.
Setup
To do this, while still connecting containers to the weave network, you can use the weave proxy. We can start the proxy with
host1$ weave launch-proxy
By default, the proxy will connect to docker at unix:///var/run/docker.sock,
and listen on port 12375. However, we can adjust the connection to docker via
the -H argument. All docker commands can be run via the proxy, so it is safe
to globally adjust your DOCKER_HOST.
host1$ export DOCKER_HOST=tcp://host1:12375
host1$ docker ps
Usage
When containers are created via the weave proxy, their entrypoint will be
modified to wait for the weave network interface to become available. When they are
started via the weave proxy, any IP addresses and networks specified in the
WEAVE_CIDR environment variable will be attached. We can create and start a
container via the weave proxy with
host1$ docker run -e WEAVE_CIDR=10.2.1.1/24 -ti ubuntu /bin/sh
or, equivalently with
host1$ docker create -e WEAVE_CIDR=10.2.1.1/24 -ti ubuntu /bin/sh
5ef831df61d50a1a49272357155a976595e7268e590f0a2c75693337b14e1382
host1$ docker start 5ef831df61d50a1a49272357155a976595e7268e590f0a2c75693337b14e1382
Multiple IP addresses and networks can be supplied in the WEAVE_CIDR variable by space-separating them, as in WEAVE_CIDR=10.2.1.1/24 10.2.2.1/24.
Usage with WeaveDNS
Containers started via the proxy can be automatically configured to use WeaveDNS for name resolution. To accomplish this we need to launch the proxy with the --with-dns option
host1$ weave launch
host1$ weave launch-dns 10.2.254.1/24
host1$ weave launch-proxy --with-dns
With this done, any containers launched through the proxy will use weaveDNS for name resolution. WeaveDNS is used in addition to any dns servers specified via the --dns option. More details on weaveDNS can be found in the weaveDNS documentation.
Usage with IPAM
To automatically assign a unique IP address to a container, weave must be told on startup what range of addresses to allocate from. For example:
host1# weave launch -iprange 10.2.3.0/24
host1$ weave launch-proxy
host1$ export DOCKER_HOST=tcp://host1:12375
With this done, we can automtaically assign an address to a container by providing a blank WEAVE_CIDR value, as in
host1$ docker run -e WEAVE_CIDR= -ti ubuntu /bin/sh
Alternatively, to enable automatic allocation of all containers without a WEAVE_CIDR, we can launch the proxy with the --with-ipam option. For example:
host1$ weave launch-proxy --with-ipam
More details on IPAM can be found in the IPAM documentation.
Limitations
- The proxy does not currently support TLS.
- If you have a firewall, you will need to make sure port 12375 is open.