Andy Maskiell saurookadook

ASCI art characters for creating diagrams

Characters

┐ └ ┴ ┬ ├ ─ ┼ ┘ ┌ │ ┤
╣ ║ ╗ ╝ ╚ ╔ ╩ ╦ ╠ ═ ╬
░ ▒ ▓ █ ▄ ▀ ■

Kafka Cheat Sheet

Display Topic Information

$ kafka-topics.sh --describe --zookeeper localhost:2181 --topic beacon
Topic:beacon	PartitionCount:6	ReplicationFactor:1	Configs:
	Topic: beacon	Partition: 0	Leader: 1	Replicas: 1	Isr: 1
	Topic: beacon	Partition: 1	Leader: 1	Replicas: 1	Isr: 1

Problem

I have two Github accounts: oanhnn (personal) and superman (for work). I want to use both accounts on same computer (without typing password everytime, when doing git push or pull).

Solution

Use ssh keys and define host aliases in ssh config file (each alias for an account).

How to?

Generate ssh key pairs for accounts and add them to GitHub accounts.

Working with multiple SSH keys

Step 1. Ensure you have an SSH client installed

ssh -V
ls -a ~/.ssh

Step 2. Set up your identity

You can create a default identity

$ ssh-keygen

Multiple SSH Keys settings for different github account

create different public key

create different ssh key according the article Mac Set-Up Git

$ ssh-keygen -t rsa -C "your_email@youremail.com"

Cheat Sheets are greate but they are not a substitute for learning the framework and reading the documentation as we most certainly have not covered every potential example here. Please refer to the Rails Command Line Docs for more information.

Command Line Generator Info

Reference

You can get all of this information on the command line.

rails generate with no generator name will output a list of all available generators and some information about global options. rails generate GENERATOR --help will list the options that can be passed to the specified generator.

Ruby on Rails Cheatsheet

Architecture

Create a new application

Install the Rails gem if you haven't done so before

	import threading


	# Based on tornado.ioloop.IOLoop.instance() approach.
	# See https://github.com/facebook/tornado
	class SingletonMixin(object):
	__singleton_lock = threading.Lock()
	__singleton_instance = None

	@classmethod

	import os
	from kafka import KafkaProducer, KafkaConsumer

	BOOTSTRAP_SERVERS=os.gentenv("KAFKA_BOOTSTRAP_SERVERS").split(",")
	TOPIC_NAME="the-topic"
	SASL_USERNAME=os.gentenv("KAFKA_SASL_USERNAME")
	SASL_PASSWORD=os.gentenv("KAFKA_SASL_PASSWORD")

	def consume():
	consumer = KafkaConsumer(TOPIC_NAME, security_protocol="SASL_SSL", sasl_mechanism="SCRAM-SHA-512", sasl_plain_username=SASL_USERNAME, sasl_plain_password=SASL_PASSWORD, bootstrap_servers=BOOTSTRAP_SERVERS)