A Newbie’s Journey into Docker, Grafana, and Prometheus

I’ll admit this up front – there’s a ton of awesome technologies out there that I’ve had my eye on, learned a little bit about, and have hardly touched since. Docker is one of those technologies… along with Grafana. Well conveniently enough for me, Anthony Nocentino just wrote a blog post on Monitoring with the Pure Storage FlashArray OpenMetrics Exporter. And this monitoring solution uses both. And best of all, it’s actually quite easy to implement – even for a clueless rookie like me!

Recap of Andy Stumbling Along…

Ages ago, I had attended an introductory session or two on Docker, and read some random blogs about it, but otherwise not really messed with it too much beyond a few examples. So I thought I’d just take the quick and dirty route, went into my team lab, and installed Docker Desktop for Windows on a random Windows VM of mine. And while I waited… and waited… and waited for the installation to run, let me go on a slight tangent here.

Tangent – Where To Run Docker From

TL;DR – Docker on Windows is a lousy experience. I expected it to “run okay for a dev box.” Nope, it was worse than that. Run it from a Linux machine if you can – you’ll be much happier.

Slightly longer “why.” Underneath the covers, Docker is essentially Linux. So to run it on Windows, you need to have Hyper-V running, essentially adding virtualization layer. And if you’re silly like me, you’ll do all of this on a Windows machine that’s really a VMware VM… so yay, nested virtualization = mediocre perf!

In my case, after rebooting my VM, Docker failed to start with a lovely “The Virtual Machine Management Service failed to start the virtual machine ‘DockerDesktopVM‘ because one of the Hyper-V components is not running” error. Some quick Google-fu revealed that I had to go into vSphere and on my VM, adjust a CPU setting for Hardware virtualization: Expose hardware assisted virtualization to the guest OS.

Three reboots later, and I finally had Docker for Windows running. Learn from lazy Andy… it would have been faster for me to just spin up a Linux VM and get docker installed and running.

Let’s Monitor a Pure FlashArray!

At this point, I could start with Anthony’s Getting Started instructions. That was super easy at least – Anthony outlined everything that I needed to do.

I did encounter another error after I ran ‘docker-compose up –detach’ for the first time: ‘Error response from daemon: user declined directory sharing‘. That one involved another Docker setting about file sharing. Once I changed that, it errored again, because I failed to restart Docker – doh! At least I didn’t have to reboot my VM again?

So finally I ran ‘docker-compose up –detach’ and stuff started appearing in my terminal – yay! I immediately went to the next step of opening a browser and got a browser error. WHUT?!? I thought something was broken, because Docker was “doing” something. But the reality is that prometheus, grafana, and the exporter, all had to do some stuff before the dashboard was up and available. Several more minutes later, I had a working Grafana and dashboard of my Pure FlashArray – yay!

Take the Time to Try Something New

All of the above took maybe a half hour at most? And a chunk of that was waiting around for stuff to complete, and other time was burned resolving the two errors I encountered. So not a huge time investment to stand up something that is really useful to monitor if you don’t have monitoring tools in place already.

But most importantly, this little experience was gratifying. It felt good to try something new again and to be able to stand this up pretty quickly and fairly painlessly. And if you don’t repeat my mistakes above, you can get your own monitoring operational even faster!

Thanks for reading!