Introduction

This projects aims for creating a web application using Flask, which is a micro-framework based on Python, that serves as an API server that requires authentication trough JWT.

How to run the web application

Running the WA is pretty straight forward:

• Clone this repository
• Install a recent version of Python >= 3.9.2 and pip >= 22.3.1
• Create a Python Virtual Environment and install the required packages for the WA which are specified inside the requirements file (that file is also included in this repository).
• Run the application by executing flask run.

Demonstratiton:

# Clone this repository
git clone https://github.com/codenoschool/jwt-flask-api-server
# Move inside the cloned repository
cd jwt-flask-api-server
# Create a python virtual enviroment
python3 -v env env
# Activate the python virtual environment
source env/bin/activate
# Install the required packages
pip install -r requirements.historical_reference
# Run the application (you can remove the --debug flag)
flask --debug run

... And that's it.

How to create the database

If you just have cloned this repository, all you need is to have your python virtual environment with the requirements installed and the execute:

# These commands are exeucted while having the python venv activated.
flask shell

That command will open up a python virtual enviroment with a flask contenxt application. There, you'll execute:

db.create_all()

That's enough to create the database models defined in app.py.

If you have set a database URI connection for SQLite (which is the default), you can inspect the database with sqlite (if you have it installed):

sqlite development.sqlite3

That'll open open up a sqlite3 interactive ssession and you can perform SQL statements there, for example:

# See the schema of the database
.schema
# Execute a SQL statement
select * from frameworks;
# Exit the sqlite3 interactive session
.exit

If you neeed a different database manager, you only need to change the URI passed as a parameter to the app.config["SQLALCHEMY_DATABASE_URI"] configuration in the file app.py. Of course, depending on your choice, you may need to install additional packages and/or connectors in your system and/or python virtual environment.

How to consume the API

The API offers different endpoints to consume, you can perform requests against these endpoints to retreive resources from the server.

Available request methods:

• GET
• POST
• PUT
• DELETE

You can use different tools to perform the HTTP requests. Here are some examples:

Using cURL

GET

curl http://127.0.0.1:5000/api/frameworks

GET (it also includes the responde headers)

curl --include http://127.0.0.1:5000/api/frameworks/1

POST

curl \
  --data '{ "name": "AngularJS" }' \
  --request POST \
  --header "Content-Type: application/json" \
  --header "JWT: <Paste here your JWT>" \
  --include \
  http://127.0.0.1:5000/api/frameworks

PUT

This is basically the same as a POST request but instead of using raw data you can also pass data retrived from a file:

curl \
  --data @fourth_framework.json
  --request PUT \
  --header "Content-Type: application/json" \
  --header "JWT: <Paste here your JWT>" \
  --include \
  http://127.0.0.1:5000/api/frameworks/2

The file fourth_framework.json has this content:

{
	"name": "AngularJS"
}

Of course, you could also use raw data just as in the POST request.

DELETE

This is the easiest one. Since this endpoint returns no content in case of finding and destroying a framework successfully, you can use the flag --include to see the response's status code which will be 204 and that HTTP code status means: NO CONTENT ("The server successfully processed the request, and is not returning any content.")

curl --include http://127.0.0.1:5000/api/frameworks/2

Other tools to perform HTTP requests

There are other tools that allow you to perform HTTP requests such as the popular Postman. It's recommended to use a python program called HTTPie due to how simple is to use it.

How to install and use HTTPie

In order to install HTTPie you could use a python virtual environment, activate it and execute the following command:

# How to install HTTPie
pip install httpie

After that, you'll have the command http available:

# Run HTTPie
http
# You'll get a simple help text after executing that last command

You can perform a request a request, that could be seen as intimidating in cURL, in HTTPie just as easy as this:

http POST :5000/api/frameworks name=VueJS JWT:<Paste your JWT here>

Much cleaner, much easier. The request URL is assumed to be "localhost" or "http://127.0.0.1" and that's the reason why only the port needs to be specified. The request is sent as JSON content type automatically. A header with name of JWT and a value of "whatever is specified after : (the dot column sign) is specified" is sent with the request.

If you need more examples you may want to execute:

http --help

Credits and refereces

This repository was created by CodeNoSchool.

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