This article is translated from https://learnk8s.io/kubernetes-network-packets, not word for word, with some of my own understanding worked in. By reading this article, you can learn how packets are forwarded inside and outside Kubernetes, starting from the original web request all the way to the container hosting the application. Kubernetes Network Requirements Before diving into the details of how packets flow through a Kubernetes cluster, let’s first clarify Kubernetes’ requirements for networking.

I recently had a requirement to collect Kubernetes’ external network access. So I set up and tried out some related projects. This post is mainly about how to install Kindling and configure Grafana to view Kubernetes network connection data. 1. What Is Kindling Kindling solves the problem of how to observe the network without intruding on the application; its functionality is mainly achieved by exposing kernel events for observation.

1. Host Service Ports 1 2 iptables -I INPUT -p tcp --dport 80 -j DROP iptables -I INPUT -p tcp -s 1.2.3.4 --dport 80 -j ACCEPT This allows only 1.2.3.4 to access port 80 on the local host. 2. Docker Service Ports For services started like docker run -d -p 80:80 shaowenchen/demo:whoami, the method above does not work; the rule has to be added to the DOCKER-USER chain.

1. Traffic Control Principles Under Linux By queuing packets, we can control how data packets are sent. This kind of control is called data shaping (shape the data), and it includes the following operations on data: Adding latency Dropping packets Reordering Duplicating, corrupting Rate control Under the qdisc-class-filter structure, controlling traffic requires three steps:

If you need to monitor the network status between two hosts, or between a host and an external service, then the Blackbox Exporter mentioned in this article is worth a try. 1. Installing Blackbox 1.1 Deploying on a Host Download the binary package 1 2 3 4 5 wget https://github.