Martin Jackson actionjack

How to Add a Watermark to Video

FFMPEG filters provide a powerful way to programmatically enhance or alter videos, and itâ€™s fairly simple to add a watermark to a video using the overlay filter. The easiest way to install ffmpeg is to download a pre-built binary for your specific platform. Then you donâ€™t have to worry about including and installing all the right dependencies and codecs you will be using.

Once you have ffmpeg installed, adding a watermark is as easy as passing your existing source through an overlay filter like so:

ffmpeg -i test.mp4 -i watermark.png -filter_complex "overlay=10:10" test1.mp4

Basically, weâ€™re passing in the original video, and an overlay image as inputs, then passing it through the filter, and saving the output as test1.mp4.

Better SSH Authorized Keys Management

A seemingly common problem that people encounter is how to handle all of your users authorized_keys file.

People struggle over management, ensuring that users only have specific keys in the authorized_keys file or even a method for expiring keys. A centralized key management system could help provide all of this functionality with a little scripting.

One piece of functionality overlooked in OpenSSH is the AuthorizedKeysCommand configuration keyword. This configuration allows you to specify a command that will run during login to retrieve a users public key file from a remote source and perform validation just as if the authorized_keys file was local.

Here is an example directory structure for a set of users with SSH public keys that can be shared out via a web server:

An introduction to curl using GitHub's API.

Basics

Makes a basic GET request to the specifed URI

curl https://api.github.com/users/caspyin

Includes HTTP-Header information in the output

	#!/bin/bash

	module=$1

	for resource in `terraform show -module-depth=1 \| grep module.${module} \| tr -d ':' \| sed -e 's/module.${module}.//'`; do
	terraform taint -module ${module} ${resource}
	done


	get_latest_release() {
	curl --silent "https://api.github.com/repos/$1/releases/latest" \| # Get latest release from GitHub api
	grep '"tag_name":' \| # Get tag line
	sed -E 's/."([^"]+)"./\1/' # Pluck JSON value
	}

	# Usage
	# $ get_latest_release "creationix/nvm"
	# v0.31.4

	http {
	log_format filt '$remote_addr - $remote_user [$time_local] "$_request" '
	'$status $body_bytes_sent "$http_referer" '
	'"$http_user_agent" "$http_x_forwarded_for"';

	server {

	location /login {
	# `set` is provided by the Rewrite module
	set $filter "password\|secret";

	#!/bin/sh

	# Generate self signed root CA cert
	openssl req -nodes -x509 -newkey rsa:2048 -keyout ca.key -out ca.crt -subj "/C=AU/ST=NSW/L=Sydney/O=MongoDB/OU=root/CN=`hostname -f`/[email protected]"


	# Generate server cert to be signed
	openssl req -nodes -newkey rsa:2048 -keyout server.key -out server.csr -subj "/C=AU/ST=NSW/L=Sydney/O=MongoDB/OU=server/CN=`hostname -f`/[email protected]"

	# Sign the server cert