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The benefits of containers and using Kubernetes for container orchestration are very well known. But what do you do if you have a workload that is not amenable to being containerized? Perhaps you have a third-party VM-based workload that you yourself can’t easily containerize, or perhaps requires a different kernel or base OS than your Kubernetes platform is running. What you would really want is

Everything you need to know about Kubernetes Services networking Services are one of the key Kubernetes primitives you need to understand to glue microservices together and expose your applications outside of the cluster. The Service resource provides an abstract way to expose an application running on a set of Pods as a network service. Sounds simple, but what’s the difference between a Cluster I

Today the Calico team merged a new dataplane option to Calico, based on eBPF, the Linux kernel’s embedded virtual machine. This exciting new dataplane will be included as a Tech Preview capability in the next version of Calico, v3.13. If you aren’t already familiar with the concept of eBPF, it allows you to write mini programs that can be attached to various low-level hooks in the Linux kernel, fo

Linux Conntrack: Why it breaks down and avoiding the problem By Alex Pollitt on Apr 26, 2019 • 6 min read Connection tracking (“conntrack”) is a core feature of the Linux kernel’s networking stack.  It allows the kernel to keep track of all logical network connections or flows, and thereby identify all of the packets which make up each flow so they can be handled consistently together. Conntrack i

kube-proxy is a key component of any Kubernetes deployment.  Its role is to load-balance traffic that is destined for services (via cluster IPs and node ports) to the correct backend pods.  Kube-proxy can run in one of three modes, each implemented with different data plane technologies: userspace, iptables, or IPVS. The userspace mode is very old, slow, and definitely not recommended!  But how sh

In this post, I’m going to cover some of the fundamentals of how Calico works. I really don’t like the idea that with these Kubernetes deployments, you simply grab a yaml file and deploy it, sometimes with little to no explanation of what’s actually happening. Hopefully, this post will servce to better understand what’s going on. What is Calico? Calico is a container networking solution created by

Project Calico is an open-source project with an active development and user community. Calico Open Source was born out of this project and has grown to be the most widely adopted solution for container networking and security, powering 8M+ nodes daily across 166 countries.