0x5d / drcon

An example project explaining service discovery, for Medellin's DevOps Meetup.

Service discovery with DRCoN

Docker + Consul + Registrator + Consul Template + Nginx

An example built for the Medellin DevOps meetup, based on this article.

Dependencies

• Docker
• Docker Machine (If you're not on Linux)
• DR-CoN Container

Run the example

You can run each container in a separate terminal window. If you're on Linux, remember to run eval $(docker-machine env <machine name>) before, so that window can communicate with the docker daemon running in your VM.

Run the Consul container:

$ docker run -it -h node \
-p 8500:8500 -p 8600:53/udp \
progrium/consul \
-server -bootstrap \
-advertise $(docker-machine ip <machine name>) \
-log-level debug

Run the Registrator container:

$ docker run -it \
-v /var/run/docker.sock:/tmp/docker.sock \
-h $(docker-machine ip <machine name>) \
gliderlabs/registrator \
consul://$(docker-machine ip <machine name>):8500

Run DR-CoN

If you haven't, pull the DR-CoN container Dockerfile.

$ git clone https://github.com/grahamjenson/DR-CoN.git

Build it:

$ cd DR-CoN
$ docker build -t dr-con .

Run it:

$ docker run -it \
-e "CONSUL=$(docker-machine ip <machine name>):8500" \
-e "SERVICE=server" \
-p 80:80 dr-con

Run the Go server:

$ docker build -t server
$ docker run --publish 6060:8080 server

Go to http://localhost:6060/Johnny, and say hello!

Note: If you're not on Linux, make sure you installed Docker Machine. Then run

$ docker-machine ip <machine name>

to get your virtual machine's IP. Replace "localhost" with that IP in the above URL, and you should be ready to go! Run more instances changing the mapped port (first one in 6060:8080), in the Run the Go server step. Notice that if you reload the page multiple times, the displayed IP changes. That's Consul Template doing its magic!

You can also check how Registrator detects when a new service is run and registers it on the Consul server. Go to http://localhost:8500 and you should see it on Consul's UI. Replace "localhost" for your VM's IP if you're not on linux.