LetsEncrypt Free SSL Certificate Tutorial

Let's Encrypt is "a free, automated, and open Certificate Authority." They provide free signed certificates as a trusted certificate authority. This tutorial walks through the process of installing certbot and requesting new certificates and renewing existing ones wit Let's Encrypt. If you are just looking to generate your own quick self-signed certificates, check out my tutorial on creating self-signed SSL certificates with OpenSSL.

Creating self-signed SSL certificates with OpenSSL

This tutorial will walk through the process of creating your own self-signed certificate. You can use this to secure network communication using the SSL/TLS protocol. For example, to run an HTTPS server. If you don't need self-signed certificates and want trusted signed certificates, check out my LetsEncrypt SSL Tutorial for a walkthrough of how to get free signed certificates.

Web Scraping with Go

Web scraping (Wikipedia entry) is a handy tool to have in your arsenal. It can be useful in a variety of situations, like when a website does not provide an API, or you need to parse and extract web content programmatically. This tutorial walks through using the standard library to perform a variety of tasks like making requests, changing headers, setting cookies, using regular expressions, and parsing URLs. It also covers the basics of the goquery package (a jQuery like tool) to scrape information from an HTML web page on the internet.

If you need to reverse engineering a web application based on the network traffic, it may also be helpful to learn how to do packet capture, injection, and analysis with Gopacket.

If you are downloading and storing content from a site you scrape, you may be interested in working with files in Go.

Taking Command Line Arguments in Java

Taking command line arguments is one of the first things you should learn how to do with a new language. In this tutorial we'll walk through a simple Java program that takes command line arguments. We'll look at how to check if any arguments were passed, access them directly by numerical index, and iterate through each argument provided.