AWS – Sumanas Tech

Artificial Intelligence and Web development

Admin — Fri, 07 Mar 2025 10:47:38 +0000

Coming Soon.

Deploy your Web Applications to the Cloud Right Away! Here is how you can!

sumanasweb — Wed, 17 Apr 2019 10:45:00 +0000

The Cloud isn’t cool anymore! Everyone here uses it! Over hyped or not cloud has deeply changed how we build and run the software. With the much more changes happening in the world of Cloud, here is what you need to know about web applications and how to deploy them in the cloud.

In this tutorial, we have given step by step guide along with the code for a quick and simple flow path.

Let’s discuss them in detail!

So what is HTTP?

HTTP (Hyper Text Transfer Protocol) is the vital factor for a website. The Internet makes use of this the servers and computers for interaction.

When we type the name of a website in a browser and hit enter, it automatically turns into an HTTP server.

This happens once you hit enter, the HTTP request is sent to the server.

What Does it Have to do with Flask?

Flask makes the process of designing simple for a web application. Moreover, Flask focuses on what users are requesting and what sort of responses need to be given back.

Flask being a Python Micro framework can run the basic web applications as well.

from flask import Flask //importing a flask
app = Flask(__name__) //__name__ represents current file of the web application
@app.route(“/”) //when the user visits the site and goes to default site this is activated
def home():
return “Hello, World!”
if __name__ == “__main__”: //assigns the name when you run your python script
app.run(debug=True) //helps to trace the errors

This is stored as main.py

Let’s run the file main.py

In your terminal or command prompt go to the folder which contains main.py file.

Type py main.py or python main.py

You can view the output similar to this on your screen

You need to take note when it says Running on http://127.0.0.1:5000/.

Where 127. 0.0.1. Represents your local computer. Go to the address and you can see

Now we shall add more routes to note the difference

from flask import Flask

app = Flask(__name__)

@app.route(“/”)

def home():

return “Hello, World!”

@app.route(“/salvador”) //added a new route to salvador

def salvador():

return “Hello, Salvador”

if __name__ == “__main__”:

app.run(debug=True)

When you again run the page, go to http://localhost:5000/salvador. You canview the one similar to this image:

Now we shall add HTML and CSS to make our website more attractive!

HTML, CSS and Virtual Environment

Here is a sample code to get started

Flask Tutorial

My First Try Using Flask

Flask is Fun

Moreover, the flask framework looks for the HTML files in the folder called ‘templates’. You need to put all your HTML files by creating this folder.

Make sure your main.py file is outside the folder!

Now we need to make changes in main.py so that we can view the HTML file we created.

from flask import Flask, render_template //will render the template from the folder

app = Flask(__name__)

@app.route(“/”)

def home():

return render_template(“home.html”) //returns to the HTML file

@app.route(“/salvador”)

def salvador():

return “Hello, Salvador”

if __name__ == “__main__”:

app.run(debug=True)

Adding CSS to our website

Similar to the folder created as ‘template’, you need to foldernamed‘static’.

Linking the CSS with our HTML file:

Flask Parent Template

First Web App

{% block content %}

{% endblock %}

Making use of Flask and virtualenv

Now you would probably know about using Flask, to go ahead let us know about the usage of virtualenv.

Why use virtualenv?

You may make use of Python for your projects besides web development. Your projects might have various versions of Python installed, different dependencies and packages.

We make use of virtualenv to create an isolated environment for your Python project. This indicates that each project can have its own dependencies regardless of what dependencies every other project has.

Getting started with virtualenv

Initially, run this command on your Command Prompt or Terminal:

pip install virtualenv

The next thing is to:

virtualenv “name of the virtual environment”

Activating the virtual environment

Now operate your terminal or command prompt. Go to the directory which contains the file called activate. The file termed as activate is found inside a folder called Scripts for Windows and bin for OS X and Linux.

For OS X and Linux Environment:

$ name of virtual environmnet/bin/activate

For Windows Environment:

name of virtual environment\Scripts\activate

You should see this at the opening of your command prompt line:

The subsequent step is to install flask on your virtual environment so that we can run the application inside our environment. Run the command:

pip install flask

Run your application and go to http://localhost:5000/

We finally made our web application!

Now let’s deploy to the cloud!

Deploying the Application

To deploy the application to Google App Engine, use this command.

gcloud app deploy

This specifies what project you are deploying.

The command will look like this:

gcloud app deploy –project [ID of Project]

The Application

Now check the URL of your application.

The application gets stored in the following way:

“your project id”.appspot.com

Final Verdict

Now you develop your web applications with flask and deploy them in the cloud with these simple steps!

If you found this article useful, do share your thoughts in the comments section anytime!

Happy Reading

Lost your PEM files? Use these steps to connect AWS Instance!

Admin — Mon, 25 Feb 2019 05:57:22 +0000

Worried about your PEM files? Here we have listed out a set of strategies you need to follow to get connected with AWS Instance.

This process is applicable if you have lost your .pem or .ppk key.

Initially, you need to take a snapshot of the root volume of your instance.

Secondly, you can create a new instance (for temporary purposes) in the same AZ just as the original instance. And remember, it is highly suggested that the recovery instance should be same as OS.

Once you create a snapshot of the instance, you need to stop the original instance.

You need to detach the root EBS volume from the original instance and make sure you make a note of volume (example /dev/xda or /dev/sda).

Once you are done with detaching, refer to the status column. Ensure the status being changed to availability. Attach this detached volume to the newly created temporary instance.

Make sure you mention your instance name while attaching the volume and device name like /dev/sdf or /dev/xdf.

The next steps are to mount it in /mnt folder since it is a secondary folder.

Commands to list attached block devices:

$ lsblk

xvda 202:0 0 8G 0 disk
└─xvda1 202:1 0 8G 0 part /
xvdf 202:80 0 8G 0 disk
└─xvdf1 202:81 0 8G 0 part

Mount the secondary device (dev/xvdf1) to ‘/mnt’ mount point using the command:

# mount /dev/xvdf1 /mnt/

If you need to change the authorized key in original instance, check the .ssh directory.

You need to create a backup of the old authorized key in the original instance.

/mnt/home/ubuntu/.ssh/authorized_keys to /mnt/home/ubuntu/.ssh/authorized_keys_back

Using the command:

cp /mnt/home/ubuntu/.ssh/authorized_keys /mnt/home/ubuntu/.ssh/authorized_keys.bck

You need to append the new key to the authorized_keys file of the original instance

You can use the Command:

cat /home/ubuntu/.ssh/authorized_keys >>

/mnt/home/ubuntu/.ssh/authorized_keys

Once you have appended, unmount the original instance volume from the temporary instance.

You can perform this with the Command:

# umount /mnt

You can attach the volume back to the original instance. This can be done /dev/sda1 during the attach of the root volume back to the instance.

Finally, you can start the original instance and connect using temporary instance pem file and access file.

Wrap Up

We hope now you would be relaxed! You can make use of this proven track strategy if you have lost your .ppm or ppk key.

If you have any other suggestions or queries, do register your comments in the comments section below!

Thanks for reading!