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

Google I/O 2017 Notes

WOW! How meaningful this below video explains about the name of  "I/O". Sundar Pichai talked a lot of Machine Learning Machine Learning is a very hot trend these days. Google uses it for their products. Google Assistant: Easily booking an online meal by talking with Google Assistant like a staff of partners, for example. Google Home: Hands-free calling. Google Photos: sharing suggestion, shared library, photo books and google lens. Youtube: 360 degree video, live stream. Kotlin became an official programming language for Android https://kotlinlang.org I'm on the way to Kotlin! ^^ Reference: [1]. https://www.youtube.com/watch?v=Y2VF8tmLFHw
Post a Comment
Read more

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

JSF, Primefaces - Invoking Application Code Even When Validation Failed

A use case I have a form which has requirements as follow: - There are some mandatory fields. - Validation is triggered when changing value on each field. - A button "Next" is enable only when all fields are entered. It turns to disabled if any field is empty. My first approach I defined a variable "isDisableNext" at a backend bean "Controller" for dynamically disabling/enabling the "Next" button by performing event "onValueChange", but, it had a problem: <h:form id="personForm"> <p:outputLabel value="First Name" for="firstName"/> <p:inputText id="firstName" value="#{person.firstName}" required="true"> <p:ajax event="change" listener="#{controller.onValueChange}" update="nextButton"/> </p:inputText> <p:outputLabel value="Last Name" for="lastName"/> <p:i...
Post a Comment
Read more

JQuery - Fixed Element during Scroll

I want to keep the position of an element likes a component on right side when I scroll down because of a very long content. Please take look at the code by visit the following link: http://jsfiddle.net/p3unbmdy/ Javascript function: $("#container").bind('scroll', function() { var fromTop = 50; var scrollVal = $("#container").scrollTop(); var top = 0; if ( scrollVal > fromTop) { top = scrollVal - fromTop; $('#rightElement').css({'position':'absolute','right':'1em','top' :top+'px'}); } else { $('#rightElement').css({'position':'static','top':'0px'}); } });
Post a Comment
Read more