Nobody needs HTML e-mails. However, you occasionally might have to write an HTML message for some weird reason. Here...
Sending a testmail from a server with a configured exim is easy as pie. From your usershell: tell exim that...
When you make a simple TCP connection to a remote server (like telnet), your client won't normally notice when...
You want to test your 1GE or 10GE internet uplink? We needed to ensure we have full 10GE to the...
Our applications not only need to be functional, they need to be fast. But, to quote Donald Knuth, premature optimization...
What is a Cookie? Google it if you do not know. How are cookies transferred between your browser and...
The asset pipeline is one of Rails' two mechanisms how stylesheets, javascripts and images from your /assets folder are processed...
Some tasks in a web application are better not done live when a user request a page, but in the...
When working with PostgreSQL, you can use pgAdmin as a GUI. While you can do most things just like on...
This is how you regain disk space from OpenStack instances if you are using kvm and qcow. If your instance...
Method lookup Understand all the terms in How Ruby method lookup works, in particular: include extend singleton class
We've already learned how to integrate user-provided images uploads to our application in 205 basic file uploads and...
Talk with a colleague and find out why we're using building some of our sites using static site...
How do HTTP requests and responses look like? What are HTTP headers? What are they used for?
If you need a postgresql extension for your database it isn't a good idea to give your applications database...
Read the Rails Guide about Active Record migrations Understand why we never use models in migrations. Checkout the repository...
Learn to store attachments in a way that is accessible by authorized users only Learn to prevent users from...
Understand how asynchronous JavaScript works: Read Henning's presentation about asynchronous Javascript (there's also a German video presentation...
In a web application you often need to move data between the client (HTML, Javascript) and the server (Ruby, Rails...
Each time thin boots, it prints a boot message : Thin web server (v1.6.3 codename Protein Powder) Maximum connections set to...
Web security basics Einführung in die Web Security 🇩🇪 provides essentials for the topic of this card. Read following chapters:
CTRL + SHIFT + ALT + N Search for any symbol in your application, like CSS classes, Ruby classes, methods, helpers etc...
Authentication is all about being able to verify the identity of a user in the context of our application.
Goal of this lesson is to understand what middlewares in Rack are good for. Rack Start with these articles: