8/29

Back at it again.

Hello everyone! Hope you're having a great Thursday. I know I am. I have the joy of sharing with you three things I learned or found interesting today.

1. What does Kubernetes kube-proxy actually do?

As i've been learning K8s i've been trying to break down each component into quick understandable parts. Today I did a quick dive into kube-proxy.

So what does kube-proxy actually do?

• Kube-proxy exists as a pod on each node.
• Kube-proxy manages the virtual IPs for services.
• In most versions, by default, Kube-proxy uses iptables to do this.
  • iptable rules interact with the Linux "netfilter" kernel hooks to make
  • this happen quickly and without much overhead.
• This allows you to use a virtual IP to route service traffic to various backend pods.
• Kube-proxy acts as a watchdog watching the k8s api and if a service changes it updates the associated IPtables rules.

By viewing the logs of a kube-proxy pod you can see which mode you are using:

kubectl logs kube-proxy-qfqxk
W0804 15:49:33.304448       1 server.go:198] WARNING: all flags other than --config, --write-config-to, and --cleanup are deprecated. Please begin using a config file ASAP.
I0804 15:49:33.618663       1 server_others.go:148] Using iptables Proxier.

Neat!

2. Linux programming interface - New book i'm reading

Ok, i'll be honest, having a ton of books at your disposal with a service like Safari leaves you reading the first chapter and really not much else for a lot of books. I'm hoping to actually keep this up and learn a lot of the low level magic that makes Linux work.

3. SafeEyes 👀 - FOSS Linux Eye strain prevention tool

This tool has been really helping my eyes lately. Every 15 minutes it asks you to do things such as stare off into the distance for 15 seconds which helps not only your eyes, but also to take a quick break and empty your mind. I was worried about the context switching, but for me this doesn't seem to impact my productivity negatively, in fact I think it's actually helping.