Istio and Jaeger (but mostly OpenTracing)

These are the files used for my presentation "Trac(k)in and hunting with Jaeger", which is delivered on November 15th 2018 for the Codemotion meetup at Quanza in Amsterdam.

Prerequisites

These scripts are tested on a Linux Mint 19.1 desktop (which is based off of Ubuntu 18.04) and requires:

• https://github.com/kubernetes/minikube (I used 1.10)
• https://www.virtualbox.org/ (Should work with other vm-drivers as well, but I only used VirtualBox)
• https://kubernetes.io/docs/tasks/tools/install-kubectl/
• https://www.docker.com/
• wget
• sha256sum

Disclaimer

This code is very far from production ready code. It's only meant as a demo and if you look at it closely, you will see that I intended to show a lot more and also still have some trial-and-error stuff in here. This is, however, the actual code that I used to run the demonstration, with all its flaws. Use at your own risk!

Repo

The repo consists of some numbered scripts, which helped me reproduce the build easily. There's also a directory with the actual Python code for the app that I demonstrated, Distributed Time.

1-setup.sh

This sets up the basic minikube environment. It'll increase the default specs to 6 CPUs and 12GB of RAM. It also enables some addons, which are not all in use. To save some time, this script also downloads most (if not all) of the images that are run within the Kubernetes "cluster" created by Minikube. I added that step to make sure I would be able to run the demo even if I didn't have (fast) internet.

2-build-time-app.sh

Before running this script, ensure your Docker environment is set to use the Minikube Docker instead of your local one with the following command:

eval $(minikube --profile jaeger docker-env)

This sets up some environment variables that instruct your docker client to connect to the docker daemon inside of the VirtualBox VM started by Minikube. Run the script and it'll build the Docker image used by the Distributed Time application.

NOTE: If you check the script, you'll see there's a load option as well, which can import a saved image created with docker save time-app > image.tar instead of building it. Again, that was a provision in the case I couldn't get it set up fast enough. (Consider it an offering to the Demo Gods!)

3-deploy-jaeger.sh

Like it says on the wrapper, it simply created the namespace jaeger and deploys the required applications inside of it. Nothing fancy. I was also playing with the Minikube Ingress addon for this, so you'll have to modify your local /etc/hosts to add a line like so:

echo "$(minikube ip) jaeger.mk" | sudo tee /etc/hosts

You can remove this entry once you're done with it. This allows you to visit http://jaeger.mk with a browser to get to the Jaeger installation.

4-deploy-time-app.sh

This will deploy the Distribute Time application inside the jaeger namespace. I did not set up an Ingress for this, I'll leave that up to you! Or you simply check how to connect to the service by running:

minikube --profile jaeger service list -n jaeger

You'll want to use the URL that's next to the router container. If all is well, you can now see the Distributed Time app in your browser! And get the traces inside of the Jaeger instance. Notice how the liveness and readiness checks get traces as well.

5-setup-istio.sh

This download the Istio 1.0.3 release and deploys it inside the namespace istio-system. This also includes a dedicated Jaeger instance, which you'll have to connect to by first creating a port forward to it with this command:

kubectl port-forward -n istio-system $(kubectl get pod -n istio-system -l app=jaeger -o jsonpath='{.items[0].metadata.name}') 16686:16686 &

You may want to note the PID that gets returned here, as you'll have to kill it in the end to stop the forward. Another way is to simply leave out the & at the end of the line and start a new terminal next to it.

Once you have the port-forward running, you can connect to that specific Jaeger instance by visiting http://localhost:16686 in your browser.

6-deploy-time-istio.sh

I'm guessing you know by now what this is supposed to do... It makes use of the Istio Ingressgateway. To connect to it, run the command minikube --profile jaeger service list -n istio-system and you'll notice a list of URLs next to the gateway service. Just use the first one and you should be able to connect to the Distributed Time app.

Thanks!