patrickshan

#!/usr/bin/env bpftrace
/*
 * trace_dns_drops traces DNS drops by ip_vs_in and ipt_do_table.
 * 
 * Background:
 * 1. Before 5.9, ip_vs_in can cause UDP packets drops when IPVS RS deleted
 *  and source port reused, See https://github.com/kubernetes/kubernetes/issues/71514 for more details.
 * 2. Misconfiguration of iptables can cause DNS drops.
 * 
 * Usage:

patrickshan

 kubectl get pods -A -ojson | jq -c '.items[] | select(.metadata.ownerReferences == null) | "\(.metadata.namespace) => \(.metadata.name)"'

patrickshan

Stevey's Google Platforms Rant

I was at Amazon for about six and a half years, and now I've been at Google for that long. One thing that struck me immediately about the two companies -- an impression that has been reinforced almost daily -- is that Amazon does everything wrong, and Google does everything right. Sure, it's a sweeping generalization, but a surprisingly accurate one. It's pretty crazy. There are probably a hundred or even two hundred different ways you can compare the two companies, and Google is superior in all but three of them, if I recall correctly. I actually did a spreadsheet at one point but Legal wouldn't let me show it to anyone, even though recruiting loved it.

I mean, just to give you a very brief taste: Amazon's recruiting process is fundamentally flawed by having teams hire for themselves, so their hiring bar is incredibly inconsistent across teams, despite various efforts they've made to level it out. And their operations are a mess; they don't real

patrickshan

# install llvm clang dependencies
sudo apt install llvm-6.0-dev libclang-dev
git clone https://github.com/iovisor/bcc.git
mkdir bcc/build; cd bcc/build
cmake .. -DCMAKE_INSTALL_PREFIX=/usr
make
sudo make install

patrickshan

#!/bin/bash

if [[ $EUID -ne 0 ]]
then
   echo "This script must be run as root"
   exit 1
fi

if [[ $# -ne 1 ]]
then

patrickshan

Create Root CA (Done once)

Create Root Key

Attention: this is the key used to sign the certificate requests, anyone holding this can sign certificates on your behalf. So keep it in a safe place!

openssl genrsa -des3 -out rootCA.key 4096

patrickshan

#!/bin/bash

instance_profile=`curl http://169.254.169.254/latest/meta-data/iam/security-credentials/`
aws_access_key_id=`curl http://169.254.169.254/latest/meta-data/iam/security-credentials/${instance_profile} | grep AccessKeyId | cut -d':' -f2 | sed 's/[^0-9A-Z]*//g'`
aws_secret_access_key=`curl http://169.254.169.254/latest/meta-data/iam/security-credentials/${instance_profile} | grep SecretAccessKey | cut -d':' -f2 | sed 's/[^0-9A-Za-z/+=]*//g'`
token=`curl -s http://169.254.169.254/latest/meta-data/iam/security-credentials/${instance_profile} | sed -n '/Token/{p;}' | cut -f4 -d'"'`

region="ap-southeast-2"
file="test.sh"
bucket="test.bucket"

patrickshan

package main

// @lizrice, mostly copied from @doctor_julz: https://gist.github.com/julz/c0017fa7a40de0543001

import (
	"fmt"
	"os"
	"os/exec"
	"syscall"
)

patrickshan

/* Exercise: Loops and Functions #43 */
package main

import (
	"fmt"
	"math"
)

func Sqrt(x float64) float64 {
	z := float64(2.)

patrickshan