vhandit

  Introduction to OpenLDAP directory service "A directory is a specialized database specially designed for searching and browsing, in addition to supporting basic lookup and update functions" A directory service can be local, providing a restricted context; or global, providing service to a much broader context. Curlie is a good example of a directory service. LDAP (Lightweight Directory Access Protocol) is a protocol for accessing directory services , specifically X.500-based directory services. OpenLDAP is an open-source implementation of LDAP. Writing system software: code comments I have read Clean Code (by Uncle Bob) and I thought that I should void comments since the code it explains its implementation itself. That is right but not always true. In this post, the author categorized the comments into 9 types. Only "trivial comments" and "backup comments" are the ones that should be avoided. I myself agree with "writing good comments is harder tha...

This is the first post in a series of articles called "Monday vhandit". You can go to the original post by clicking on each head title. Character encodings: essential concepts This article points out why Unicode matters and differentiates among concepts: character sets, coded character set (unit is code points), and character encoding. Explained from First Principles: the Internet The very structural and well-explained article contains almost concepts of the Internet. I really appreciated the author's effort put on that post. Dev Community - DevDojo I just joined this community. DevDojo is really a developer-oriented platform. It is very nice, easy, fast, and sufficient to write (Markdown supported) and search for a post. The best of it, you also have a personal blog for your posts at "<your_username>.devdojo.com". My username is vnnvanhuong Everything you need to know about HTTP security headers A good collection of HTTP security-related headers. Moreover...

Motivation We all follow the client-server model using the HTTP protocol for most of our web apps today. In development, we simply may have a backend API server and a frontend (web pages or mobile apps) only. However, it seemed that a proxy server is always required for production. In fact, most of the hardest issues in production come from integration. The requests and responses might be modified by the proxy server. Therefore, the understanding of HTTP protocol is one of the key skills to resolve those issues. I wanted to dive deep into HTTP with some core concepts such as caching, cookies, and CORS. I didn't intend to go quickly rather than moved slowly to have a well understanding of what I do. Prepare a server The easiest way is to use my laptop as a server then I can just use "localhost". I can also use ngrok to make my web server online. Finally, I use an online tool such as RedBot to check the HTTP headers. To make it more excited though, I deployed the app on A...

  Introduction I write this user guide to help us (you and me) have a good collaboration at work. I hope you also share yours. How I view success We all feel passionate and happy at work. We all enjoy discussing transparently. We take it easy to give and receive feedback. After all, we together develop and bring valuable applications to users. How I communicate I mostly prefer a face-to-face conversation. Just leave me a message on Slack if you don't want to come to my desk. For a big topic which takes more than 30 minutes, we should have a meeting. Only send me emails only if stuff is very formal or out-of-office hours Things I do that may annoy you I do practice the Pomodoro technique so that sometimes you see me in the "do not disturb" mode. Often to make things clear, I am at ease talking   frankly   with you. What gains and loses my trust It is easy to gain my trust when you commit to what you say. You show your passion and endeavors to achieve that. It is easy to lo...

Today, I faced a problem that I could not upload my archive file with gzip format on Firefox, even it worked on Chrome. I was using macOS. My application had a setting to whitelist accepted files. I’ve already added "application/gzip" to that list. "It’s strange!", I thought. I finally figured out that my uploaded file's type actually was "application/x-gzip" on Firefox. I also asked my colleagues to check their uploaded files on Window and Ubuntu. Hmm… they were totally different! It was "application/x-compressed" on Window, and was "application/x-compressed-tar" on Ubuntu. In fact, gzip is already standardized by IANA. There is a note in RFC-6713 as below: "Some applications have informally used media types such as application/gzip-compressed, application/gzipped, application/x-gunzip, application/x-gzip, application/x-gzip-compressed, and gzip/document to describe data compressed with gzip. The media types defin...

I was using Meteor for my messenger project. I was so curious about the real time connection. I wanted to know how exactly this mechanism works. In this post, I will go through the DDP Specification, an overview of WebSocket, and a simple demo about how to subscribe a publication of Rocket.Chat (containing a DDP server) from an external webpage. At a glance, I knew that Meteor invented a protocol called DDP which uses for handling real time connection. So then, what is DDP? "DDP (Distributed Data Protocol) is the stateful WebSocket protocol that Meteor uses to communicate between the client and the server." [1] All right! Why does DDP matter? "DDP is a standard way to solve the biggest problem facing client-side JavaScript developers: querying a server-side database, sending the results down to the client, and then pushing changes to the client whenever anything changes in the database" . [2] In order to understand deeply the protocol, I decided ...

I enjoyed reading this post: https://words.steveklabnik.com/the-culture-war-at-the-heart-of-open-source Here is my highlight: If you ask a random developer what “open source” means to them, you won’t often hear “software that follows the Open Source Definition.” If you ask them “what’s the difference between free software and open source software,” you’ll often hear “aren’t those the same thing?” or “you can charge money for open source software, it’s not always free.” You may even hear “it’s on GitHub.” In brief, there was a man Richard Stallman (and his team) starting a project called "GNU Project" in 1983. This project was about to develop a free software system. The term "free" here meant "freedom", not only about the price. The Free Software Foundation appeared to support this project. But then, the term "free software" was so ambiguous. "In addition, the ambiguity of the term “free software” was seen as discouraging busine...