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Docker FTW!

15 November 2014

The past few days I was playing around with Docker to set up a small testbed with ActiveMQ, StatsD and Grafana. I want to test how to collect metrics from Apache Camel routes and display them via a webfrontend in nice graphcs. That’s exactly what Grafana is doing best.

I started with running a few ActiveMQ instances via Docker. Then I created a simple Camel application using camel-archetype-activemq and modified it to write a random amount of messages into my already running ActiveMQ instances using the failover Transport.

Now, to the installation of Grafana. To avoid jumping through all the hoops, I decided to spin up another Docker container using kamon-ios Grafana image. But I ran into some problems when I tried to add a new dashboard to Grafana and add my counters to a panel. I opened an issue, but I already found a workaround for myself: I upgraded the Dockerfile to use Grafana 1.8.1, the latest version and it fixed my problems. If you have similar problems, try to replace the following lines in the Dockerfile and rebuild the image:

# Install & Patch Grafana
RUN     mkdir /src/grafana &&\
        git clone https://github.com/grafana/grafana.git /src/grafana &&\
        cd /src/grafana &&\
        git checkout v1.8.1

#ADD     ./grafana/correctly-show-urlencoded-metrics.patch /src/grafana/correctly-show-urlencoded-metrics.patch
#RUN     git apply /src/grafana/correctly-show-urlencoded-metrics.patch --directory=/src/grafana                                         &&\
RUN        cd /src/grafana &&\
           npm install &&\
           npm install -g grunt-cli &&\
           grunt build 

What I did here is checking out v1.8.1 of Grafana and then not applying the patch that tried to fix an issue with urlencoded metrics, that was applied to the sources before building Grafana. I hope I get a response on my issue, if this is causing problems - but maybe it’s just my local setup…

Anyhow, after working around this little issue, I was able to send metrics into statsd from my Camel route. From Zero to having 2 ActiveMQ instances, a StatsD-Graphite-Grafana stack running and my Camel route reporting metrics it took me about 2 hours - not counting the fix to the Dockerfile. That’s why I think Docker is here to stay.

Everyone likes screenshots, so here is one of the graph I got on Grafana. :)

Camel Route using ActiveMQ and sending Metrics into Statsd, displayed in Grafana