Sun Lei jerry-sl

Linking my account jerry-sl on GitHub with my address 5CRtUCqUz2AYx8yp9K4jhHi66sTEVWPtq8TnF7MjCG5A69hc on Substrate in mycryptoprofile.io, and the challenge code is: cc3f0380fc9dc3fcacaecd06d1b2db78. #LitentryVerifyMyAddress

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

Not all random values are created equal - for security-related code, you need a specific kind of random value.

A summary of this article, if you don't want to read the entire thing:

Don't use Math.random(). There are extremely few cases where Math.random() is the right answer. Don't use it, unless you've read this entire article, and determined that it's necessary for your case.
Don't use crypto.getRandomBytes directly. While it's a CSPRNG, it's easy to bias the result when 'transforming' it, such that the output becomes more predictable.
If you want to generate random tokens or API keys: Use uuid, specifically the uuid.v4() method. Avoid node-uuid - it's not the same package, and doesn't produce reliably secure random values.
If you want to generate random numbers in a range: Use random-number-csprng.

You should seriously consider reading the entire article, though - it's

	#!/bin/bash
	while true; do
	pid=`ps -ef \|grep binary_name \|grep -v grep \|awk '{print $2}'`
	if [ -n "$pid" ]; then
	kill -15 $pid
	echo "The process is exiting, it may take some time, forcing the exit may cause damage to the database, please wait patiently..."
	sleep 1
	else
	echo "binary_name process killed successfully!"
	break

	// 删除所有已经停止的container
	docker rm -v $(docker ps -aq -f status=exited)
	// 从dockerhub下拉镜像
	docker pull redis
	// 后台启动容器
	docker run --name myredis -d redis
	// 启动另外一个容器并链接到myredis:redis容器
	docker run --rm -it --link myredis:redis redis /bin/bash

	# Set variables in .bashrc file

	# don't forget to change your path correctly!

	export GOPATH=$HOME/golang
	export GOROOT=/usr/local/opt/go/libexec
	export PATH=$PATH:$GOPATH/bin
	export PATH=$PATH:$GOROOT/bin

	go get -u golang.org/x/crypto/bcrypt
	go get -u golang.org/x/crypto/blowfish
	go get -u golang.org/x/crypto/bn256
	go get -u golang.org/x/crypto/cast5
	go get -u golang.org/x/crypto/curve25519
	go get -u golang.org/x/crypto/hkdf
	go get -u golang.org/x/crypto/md4
	go get -u golang.org/x/crypto/nacl/box
	go get -u golang.org/x/crypto/nacl/secretbox
	go get -u golang.org/x/crypto/ocsp

	var fs = require('fs');
	var parse = require('csv-parse');
	var Web3 = require('web3');
	var abi = require('./abi.json');
	var _ = require('lodash');
	const Tx = require('ethereumjs-tx');


	var web3 = new Web3(new Web3.providers.HttpProvider("https://ropsten.infura.io/scure_key"));
	//var inputFile = 'data.csv';

	alias proxy="export ALL_PROXY=socks5://127.0.0.1:1080"
	alias unproxy="unset ALL_PROXY"
	alias ip="curl -i http://ip.cn"

	git config --global http.proxy 'socks5://127.0.0.1:1080'

	git config --global https.proxy 'socks5://127.0.0.1:1080'