Skip to main content

Set up a web server for learning HTTP headers


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 AWS EC2. It was quite easy to launch an EC2 instance by using the wizard setup of AWS. Just simply use default settings for most of the cases. I was just curious about how to creating a new VPC (Virtual Private Cloud). To understand what exactly the IPv4 address and CIDR are, I first started to grab some knowledge about those topics by watching the following videos on YouTube


Next, I tried to create and do configure a virtual private network using Cisco Packet Tracer. I needed to configure IP address for involved devices: routers, servers, and laptop. Also, I did configure the routing tables for each router so that I could send packets among devices.

Coding

I used Express for my web server simply serving static files. I configured the HTTP header easily through passing the options of "express.static" middleware.

Deployment

Docker is my favourite tool for deployment. I created an image for my container running on my EC2 instance which I have already installed Docker. I also applied some best practices of Node.js and Docker. I built and pushed my Docker image into Docker Hub so that I could pull the image within the EC2 instance.

Happy coding!
Labels:

Comments

Post a Comment

Popular posts from this blog

Junit - Test fails on French or German string assertion

In my previous post about building a regex to check a text without special characters but allow German and French . I met a problem that the unit test works fine on my machine using Eclipse, but it was fail when running on Jenkins' build job. Here is my test: @Test public void shouldAllowFrenchAndGermanCharacters(){ String source = "ÄäÖöÜüß áÁàÀâÂéÉèÈêÊîÎçÇ"; assertFalse(SpecialCharactersUtils.isExistSpecialCharater(source)); } Production code: public static boolean isExistNotAllowedCharacters(String source){ Pattern regex = Pattern.compile("^[a-zA-Z_0-9_ÄäÖöÜüß áÁàÀâÂéÉèÈêÊîÎçÇ]*$"); Matcher matcher = regex.matcher(source); return !matcher.matches(); } The result likes the following: Failed tests: SpecialCharactersUtilsTest.shouldAllowFrenchAndGermanCharacters:32 null A guy from stackoverflow.com says: "This is probably due to the default encoding used for your Java source files. The ö in the string literal in the J...
5 comments
Read more

How to apply Lean - Kanban for your business

This is the topic of Scrum Breakfast meetup this time, speaker: Ms. Phuong Bui - Technical Project Manager of YOOSE Pte. Ltd. http://www.meetup.com/Scrum-Breakfast-Vietnam-Agile-and-Scrum-Meetup/events/230313727/ Lean comes from Lean manufacturing is a method that focuses on elimination of wastes. In other words, this is a set of principles for archiving the quality, speed and customer alignment. The first time I knew about the term "Lean" is  from the book Software Craftsmanship . Sandro recommends if we want to transform our pet projects into a real business, we should get familiar with Lean Startup concepts. In this talk, Ms. Phuong pointed out some major wastes includes information (ex: unclear requirements), processes (ex: waiting), physical environment and people. Knowing what the problems should be the best way to eliminate them. The difference between  Single item flow and Batch processing is the second main point; and it is the Lean's idea. Batch pr...
Post a Comment
Read more

The HelloWorld example of JSF 2.2 with Myfaces

I just did by myself create a very simple app "HelloWorld" of JSF 2.2 with a concrete implementation Myfaces that we can use it later on for our further JSF trying out. I attached the source code link at the end part. Just follow these steps below: 1. Create a Maven project in Eclipse (Kepler) with a simple Java web application archetype "maven-archetype-webapp". Maven should be the best choice for managing the dependencies , so far. JSF is a web framework that is the reason why I chose the mentioned archetype for my example. 2. Import dependencies for JSF implementation - Myfaces (v2.2.10) into file pom.xml . The following code that is easy to find from  http://mvnrepository.com/  with key words "myfaces". <dependency> <groupId>org.apache.myfaces.core</groupId> <artifactId>myfaces-api</artifactId> <version>2.2.10</version> </dependency> <dependency> <groupId>org.apache.myfaces.core<...
Post a Comment
Read more

MS SQL Server Views

"Creates a virtual table whose contents (columns and rows) are defined by a query. Use this statement to create a view of the data in one or more tables in the database. For example, a view can be used for the following purposes: - To focus, simplify, and customize the perception each user has of the database. - As a security mechanism by allowing users to access data through the view, without granting the users permissions to directly access the underlying base tables. - To provide a backward compatible interface to emulate a table whose schema has changed." [1] Beside that, our team used view in order to improve the performance of our web apps when a database has a very complicated relationship between its tables by using ORM Frameworks such as Hibernate. Example code: --create CREATE VIEW placeholders AS SELECT EMPKEY AS empkey, CONNUMB AS connumb, EMPNBR AS empNbr, ACEEMPN AS empFirstName, ACEEMPFN AS empLastName, EMPNAM AS empFullName, ...
Post a Comment
Read more

Think like a Engineering Manager

Off-boarding Members can leave the company for various reasons, and as a manager, it is important to take action. Hoping for the best is not a strategy. In the case of a low-performing member, I can kindly issue an official warning, set clear objectives for improvement, and re-evaluate the results. If there is a conflict between members, I need to be mindful and go beyond the situation to list our expectations with corresponding actions. Finally, if a member has a big chance to grow at another company, I can have an honest discussion with that member about the trade-offs. Balance at Work As an engineering manager, it is important to balance involvement in meetings and getting your hands dirty on some topics. The goal is to become a companion to teams. Here are my two actions to deal with the situation: Dedicate time for important-but-not-urgent tasks and prioritize them daily. Categorize work into four lines including management, project support, OKRs, and self-study. Management Conduc...
Post a Comment
Read more