Kubernetes Health Check: How to Make it Simpler

KubeEye supports you in the task of ensuring that your cluster is performing well and ensure all your best practices are being followed.

Photo by Kent Pilcher on Unsplash

Kubernetes has become the new normal to deploy our applications and other serverless options, so the administration of these clusters has become critical for most enterprises, and doing a proper Kubernetes Health Check is becoming critical.

This task is clear that it is not an easy task. As always, the flexibility and power that technology provides to the users (in this case, the developers) also came with a trade-off with the operation and management’s complexity. And this is not an exception to that.

We have evolved, including managed options that simplify all the underlying setup and low-level management of the infrastructure behind it. However, many things need to be done for the cluster administration to have a happy experience in the journey of a Kubernetes Administrator.

A lot of concepts to deal with: namespaces, resource limits, quotas, ingress, services, routes, crd… Any help that we can get is welcome. And with this purpose in mind, KubeEye has been born.

KubeEye is an open-source project that helps to identify some issues in our Kubernetes Clusters. Using their creators’ words:

KubeEye aims to find various problems on Kubernetes, such as application misconfiguration(using Polaris), cluster components unhealthy and node problems(using Node-Problem-Detector). Besides predefined rules, it also supports custom defined rules.

So we can think like a buddy that is checking the environment to make sure that everything is well configured and healthy. Also, it allows us to define custom rules to make sure that all the actions that the different dev teams are doing are according to the predefined standards and best practices.

So let’s see how we can include KubeEye to do a health check of our environment. The first thing we need to do is to install it. At this moment, KubeEye only offers a release for Linux-based system, so if you are using other systems like me, you need to follow another approach and type the following commands:

git clone https://github.com/kubesphere/kubeeye.git
cd kubeeye
make install

After doing that, we end up with a new binary in our PATH named `ke`, and this is the only component needed to work with the app. The second step we need to do to get more detail on those diagnostics is to install the node problem detector component.

This component is a component installed in each node of the cluster. It helps to make more visible to the upstream layers issues regarding the behavior of the Kubernetes cluster. This is an optional step, but it will provide more meaningful data, and install that, we need to run the following command.

ke install npd

And now we’re ready to start checking our environment, and the order is as easy as this one.

ke diag

This will provide an output similar to this that is compounded by two different tables. The first one will be focused on the Pod and the issues and events raised as part of the platform’s status, and the other will focus on the rest of the elements and kinds of objects for the Kubernetes Clusters.

Output From The Ke Diag&Nbsp;Command

The table for the issues at the pod level has the following fields:

  • Namespace where the pod belongs to.
  • Severity of the issue.
  • Pod Name that is responsible for the issue
  • EventTime of where this event has been raised
  • Reason for the issue
  • Message with the detailed description of the issue

The second table for the other objects has the following structure:

  • Namespace where the object that has an issue that is being detected is deployed.
  • Severity of the issue.
  • Name of the component
  • Kind of the component
  • Time of where this issue has been raised
  • Message with the detailed description of the issue

Command’s output can also show other tables if some issues are detected at the node level.

Today we cover a fascinating topic as it is the Kubernetes Administration and introduce a new tool that helps your daily task.

I truly expect that this tool can be added to your toolbox and ease the path for a happy and healthy Kubernetes Cluster administration!

Alexandre Vazquez: