Docker Networking Magic

I have been quiet on here as I am in the process of writing again, one of things I have been looking at is Dockers new networking features. This gave me an excuse to have a play with Weave. Rather than go into too much detail here, lets go all click bait because you won’t believe what happened next.

I launched two hosts in Digital Ocean↗, one in London and then one in New York City using Docker Machine;

docker-machine create \
 - driver digitalocean \
 - digitalocean-access-token your-digital-ocean-api-token-goes-here \
 - digitalocean-region lon1 \
 - digitalocean-size 1gb \
mesh-london

docker-machine create \
 - driver digitalocean \
 - digitalocean-access-token your-digital-ocean-api-token-goes-here \
 - digitalocean-region nyc2 \
 - digitalocean-size 1gb \
mesh-nyc

Once both hosts were up and running I downloaded the Weave binaries on each host;

docker-machine ssh mesh-london ‘curl -L git.io/weave -o /usr/local/bin/weave; chmod a+x /usr/local/bin/weave’
docker-machine ssh mesh-nyc ‘curl -L git.io/weave -o /usr/local/bin/weave; chmod a+x /usr/local/bin/weave’

Once the binary was on each host, I launched Weave on each host making sure I provided a password so that traffic between the host machines would be encrypted;

docker-machine ssh mesh-london weave launch - password m3ga_5ecret_pa55w0rd
docker-machine ssh mesh-nyc weave launch - password m3ga_5ecret_pa55w0rd

Now Weave is running on both my hosts, I instructed the mesh-nyc host to connect to the IP address of the mesh-london host;

docker-machine ssh mesh-nyc weave connect “$(docker-machine ip mesh-london)”

and finally check the status of the Weave cluster;

docker-machine ssh mesh-nyc weave status

There should be two peers and 2 established connections.

This is where it gets interesting. Launching a NGINX↗ container on the New York City host by running;

docker $(docker-machine config mesh-nyc) run -itd \
 - name=nginx \
 - net=weave \
 - hostname=”nginx.weave.local” \
 - dns=”172.17.0.1" \
 - dns-search=”weave.local” \
russmckendrick/nginx

and then on the London host, try wgetting the page being served by NGINX (its just a plain one which says Hello from NGINX);

docker $(docker-machine config mesh-london) run -it \
 - rm \
 - net=weave \
 - dns=”172.17.0.1" \
 - dns-search=”weave.local” \
russmckendrick/base wget -q -O- http://nginx.weave.local

and then finally ping the NGINX container;

docker $(docker-machine config mesh-london) run -it \
 - rm \
 - net=weave \
 - dns=”172.17.0.1" \
 - dns-search=”weave.local” \
russmckendrick/base ping -c 3 nginx.weave.local

If you can’t be bothered to run it yourself, and who can blame you, here is an asciicinema↗ recording;

As you can see, with no effort on my part other than the commands above I had encrypted, multi-host container networking !!!

Don’t forget to get teardown the two Digital Ocean↗ hosts if you brought them up;

docker-machine stop mesh-london mesh-nyc
docker-machine rm mesh-london mesh-nyc

For further reading on Weave Net please see their documentation↗.

Docker Networking Magic

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