tsanghan

kube-proxy nftables and iptables vs a Service with 100k endpoints

Background

Iptables performance is limited mainly by two reasons:

• Latency on the first packet of a connection caused by the linear search rule matching
• Latency on the programming latency caused by the need to save and restore all the lines to the kernel in each transaction

The kernel community moved to nftables as replacement of iptables, with the goal of removing the existing performance bottlenecks. Kubernetes has decided to implement a new nftables proxy because of this and another reasons explained in more detail in the corresponding KEP and during the Kubernetes Contributor Summit in Chicago 2023 on the session [Iptables, end of

tsanghan

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    component: etcdclient
    tier: debug
  name: etcdclient
  namespace: default
spec:

tsanghan

#! /usr/bin/env bash

set -euo pipefail

api() {
  local type endpoint registry image arg url
  type=$1 endpoint=$2 registry=$3 image=$4 arg=$5
  url="https://$registry/v2/$image/$endpoint/$arg"
  curl --config - <<<"-u $ARTIFACTORY_CREDS" -H "Accept: $type" "$url"
}

tsanghan

upstream warehouse_inventory {
    zone inventory_service 64k;
    server 10.0.0.1:80;
    server 10.0.0.2:80;
    server 10.0.0.3:80;
}

upstream warehouse_pricing {
    zone pricing_service 64k;
    server 10.0.0.7:80;

tsanghan

Add the following in .zshrc:

...
plugins=(osx git zsh-autosuggestions zsh-syntax-highlighting zsh-nvm docker kubectl)
...

### Fix slowness of pastes with zsh-syntax-highlighting.zsh
pasteinit() {
  OLD_SELF_INSERT=${${(s.:.)widgets[self-insert]}[2,3]}
  zle -N self-insert url-quote-magic # I wonder if you'd need `.url-quote-magic`?

tsanghan

Save these files as ~/.config/systemd/user/some-service-name.*

Run this now and after any modifications: systemctl --user daemon-reload

Try out the service (oneshot): systemctl --user start some-service-name

Check logs if something is wrong: journalctl -u --user-unit some-service-name

Start the timer after this user logs in: systemctl --user enable --now some-service-name.timer

tsanghan

Commands Reference

1. Start a new tmux named session tmux new -s terminal-capture
2. Split the screen using these commands,

• vertical split <C-b>"
• horizontal split <C-b>%

3. To navigate between the panes,

• To goto Left pane <C-b> left-key
• To goto Right pane <C-b> right-key
• To goto Top pane up-key

tsanghan

python3 -c 'import sys, yaml, json; j=json.loads(sys.stdin.read()); print(yaml.safe_dump(j))'

tsanghan

Regular Expression Engine Comparison Chart

Many different applications claim to support regular expressions. But what does that even mean?

Well there are lots of different regular expression engines, and they all have different feature sets and different time-space efficiencies.

The information here is just copied from: http://regular-expressions.mobi/refflavors.html

tsanghan

#!/bin/bash
#
# Install required apt packages
#
REQUIRED_PKG=(apt-transport-https \
              zsh \
              ansible \
              powerline \
              python3 \
              python3-powerline \