Kubernetes

Kubernetes Konnectivity xfr-channel-size Configuration I have often encountered situations where network connectivity between the API server and cluster nodes becomes complicated. Firewalls, network policies, and VPC configurations can block direct communication. This is where Konnectivity comes in. It provides a network proxy system that tunnels traffic through these barriers. During my work with Konnectivity, I encountered the warning message Receive channel from agent is full in my cluster logs. I asked the Kubernetes community for help but didn’t receive a response. I also couldn’t find any documentation explaining what this warning meant or how to fix it, or even any documentation about this component :(. So, this led me to reading the source code to understand what xfr-channel-size actually does, which controls data buffering, and getting it right can make a difference in how your cluster performs under load. ...

This blog post is a collection of my personal notes on networking. For a long time, I had to jump between different notebooks to connect concepts; from core networking theory, to Linux internals, all the way up to Kubernetes and CNI. This post is my attempt to combine all those notes into a single, logical document. We’ll follow a step-by-step path. We’ll start with fundamental network concepts, then see how those are implemented in Linux, which is the foundation for most modern virtual networking. Finally, we’ll see how Kubernetes builds on top of it all. ...

Kubernetes Client-Side Indexing This post is part of Kubernetes controller development. Check out the first part on Diving into controller-runtime | Manager if you are interested in controller-runtime. When working with Kubernetes Operators, read requests (get and list) to the Kubernetes API server are handled by an in-memory cache that is maintained by client-go to reduce the load on your API server. This cache can be enhanced with indexes to retrieve resources more efficiently. ...

This guide is a summary of AWS EKS Best practices documentation to help me to skim through some concepts that i usually refer to. For details, please have a look to official EKS docs mentioned on Resources section. EKS (Amazon Elastic Kubernetes Service) It manages Kubernetes control-plane on behalf of you, ensures that each cluster has its own control plane. So, as an end-user, you only need to handle your workloads in worker nodes. All control plane related stuff will be handled by AWS. ...

Introduction controller-runtime package has become a fundamental tool for most Kubernetes controllers, simplifying the creation of controllers to manage resources within a Kubernetes environment efficiently. Users tend to prefer it over client-go. The increased adoption of projects like Kubebuilder or Operator SDK has facilitated the creation of Kubernetes Operator projects. Users need to implement minimal requirements to start with Kubernetes controllers, thanks to these projects. As a developer working on Kubernetes projects, I inevitably touch code pieces utilizing controller-runtime Whenever I dive into code base, I always learn something new about the underlying mechanism of Kubernetes. ...