Rahul Mishra mrahul17

FFmpeg cheat sheet

A list of useful commands for the FFmpeg command line tool.

Download FFmpeg: https://www.ffmpeg.org/download.html

Full documentation: https://www.ffmpeg.org/ffmpeg.html

Basic conversion

Adding Google Sign In With Rails and React

For this blog post we will be using ruby version 2.4.0 and rails version 5.1.4 as backend and React/Redux as frontend. Adding Google Sign in functionality in your application can be done in two popular ways.

Adding google sign in functionality in the frontend with google api client gapi.
Adding google sign in functionality logic in the backend server.

If your application has separate backendend with APIs feeding data to the frontend React application, I suggest you to follow the step 2. If you want yo enhance your application security, then you implement both.

Semantic Commit Messages

See how a minor change to your commit message style can make you a better programmer.

Format: <type>(<scope>): <subject>

<scope> is optional

Example

Rails naming conventions

General Ruby conventions

Class names are CamelCase.

Methods and variables are snake_case.

Methods with a ? suffix will return a boolean.

git add -p is your friend

git add -p is basically "git add partial (or patch)"

Patch mode allows you to stage parts of a changed file, instead of the entire file. This allows you to make concise, well-crafted commits that make for an easier to read history. This feature can improve the quality of the commits. It also makes it easy to remove parts of the changes in a file that were only there for debugging purposes - prior to the commit without having to go back to the editor.

It allows you to see the changes (delta) to the code that you are trying to add, and lets you add them (or not) separately from each other using an interactive prompt. Here's how to use it:

from the command line, either use

git add -p

	# Redis Cheatsheet
	# All the commands you need to know


	redis-server /path/redis.conf # start redis with the related configuration file
	redis-cli # opens a redis prompt


	# Strings.

	#
	# Ce fichier de configuration Logstash permet d'effectuer la copie d'index soit:
	# - à l'intérieur d'un même cluster Elasticsearch
	# - entre différents clusters Elasticsearch
	#
	# Utile dans le cas où nous voulons réindexer un index à l'aide de nouveaux mappings ou pour
	# dupliquer la production vers un autre environnement de tests.
	#
	# Pour invoquer la commande:
	# LS_HEAP_SIZE="2048m" /path/to/bin/logstash -w 2 -f copie-elasticsearch.conf

	input {
	elasticsearch {
	hosts => [ "HOSTNAME_HERE" ]
	port => "9200"
	index => "INDEXNAME_HERE"
	size => 1000
	scroll => "5m"
	docinfo => true
	scan => true
	}

	# Ask for the user password
	# Script only works if sudo caches the password for a few minutes
	sudo true

	# Install kernel extra's to enable docker aufs support
	# sudo apt-get -y install linux-image-extra-$(uname -r)

	# Add Docker PPA and install latest version
	# sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 36A1D7869245C8950F966E92D8576A8BA88D21E9
	# sudo sh -c "echo deb https://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"