While Kubernetes is one of the best things to happen to cloud and container hosting, it still has its problems. It is one of the most complicated pieces of software for people who are new to this way of putting their websites and services on the Internet. That complexity can get in the way of doing many simple things, and it can also lead to problems later when you are running Kubernetes at scale. You might find a Kubernetes tutorial on the Internet that talks about what you can do to solve common problems, and these are the things that most people find happening to them when they are running it. As a system administrator, troubleshooting Kubernetes scenarios is one of the most important skills for you to obtain.
Despite its famous problems, Kubernetes is still a great solution. However, you really have to make sure that it is the right solution for your specific needs. Kubernetes is notoriously complex, as it was written for web-scale organizations. It might not be too useful for you if you’re a small up-and-coming webmaster with only a few containers to administer.
This is a tool that was built by Google, so you have to think about that level of scalability. Google has multiple data centers with hundreds of thousands of servers across its entire infrastructure. Kubernetes was created to manage that level of complexity. However, it is still worth it because it gives you so much value with orchestration and managing your containers. It does a lot of things automatically, and this helps you reduce the number of people you need working on your infrastructure. As an organization, it will save you time and money.
Before you and your organization embark on any sort of mission to deploy Kubernetes, one of the first things you need to do is figure out where you’re going to get help. Having that help will improve your confidence as you take on some of the more troubling issues that can occur with Kubernetes. The first place you can look is on Stack Overflow, which has a dedicated section for Kubernetes issues. There are also dedicated Slack channels separated by country. There is also an official forum at https://discuss.kubernetes.io/. These resources should be good enough to solve the basic problems you will encounter in day-to-day life.
As with anything in life, you need to spend a lot of time learning how to use Kubernetes before you can start working with it. The majority of your problems will come at the start when you are new to using it. The easiest path for you to take is to follow the various Kubernetes tutorials on https://kubernetes.io/ to set it up and create your own working test environment.
The Kubernetes tutorial will show you how to create a learning cluster in only a few minutes. This learning cluster will allow you to do a lot of things you wouldn’t want to try in your production environment. It will also allow you to test certain hypotheses you might have. This can eventually prove useful, as you will end up having a lot of things go wrong in the production environment. You might be able to replicate them in your test environment, and this is one of the most common ways you will solve problems in the future. Being able to simulate problems and come up with ways to solve them is crucial to growing your skill set.
One of the first and more common problems you will encounter as a small-scale user of Kubernetes is the fact that it is very difficult to have manual granularity over your cluster. The main reason for this is that Kubernetes was designed for Google-scale companies. We are talking about hundreds of thousands of servers, so it is very difficult to adjust the default settings. This is something you will have to learn to live with. Kubernetes demands total control over how your cluster is structured and how work is done across that cluster. If you are looking for something that will give you better control, then this isn’t the tool for you.
Let’s go into some of the more common problems that you can solve and see what you need to do.
The most common problem you are going to have with Kubernetes is with the various Pods running across your cluster. As Pods are the foundational unit of computation, they present the greatest challenge to you having a highly available system. If a Pod fails, Kubernetes is likely to automatically create a new replica and have it running on another execution unit inside your cluster. However, you might want to know how to figure out what went wrong with that Pod. This is where debugging Pods comes into play.
The command kubectl is the solution to all of your problems with Pods. Kubernetes gives you this built-in tool to act as a control center for all of your needs. You can use it to do a lot of problem-solving when it comes to Pods. The first thing you can do with this command is debug all of your Pods. The command will also give you status reports to tell you if a Pod is healthy or not, which should be one of the most important things in the day-to-day monitoring of your entire cluster. Finally, it gives you a basic view into logs and knowledge of what is happening with the applications running within a Pod. You should also look at whether your Pods are using too many physical resources or not.
This is a very niche problem, but it should be mentioned because, in the world of containers, it is quite common for people to run into scaling issues. Load-balancing will be a very distinctive problem that could potentially happen to you. The easy solution is to run HAProxy as a two-step load balancer in front of your Kubernetes cluster. You can also substitute HAProxy for NGINX.
Like Pods, services are also controllable with kubectl. There is a Kubernetes practical example on the official website that talks about what you can do to fix problems with services. For every problem here, there is always a good Kubernetes solution that will address whatever you might encounter. In fact, many Kubernetes problems can be solved with a cool and calm head and by analyzing the basic components that make up a cluster. Within the control command, you can get endpoints for a variety of services, and they should tell you whether everything is running well or not. You can also use the command to set endpoints for services that are missing them.
There might be times when traffic doesn’t forward from one network space to the next. The main reason this happens is that the proxy cannot get in contact with your Pod. You have to check to make sure the Pods are working correctly, and then you have to look in the port forwarding to verify that everything functions smoothly. Finally, you have to check if the ports are mapped correctly, which isn’t something that Kubernetes does automatically.