REST API Login Logout Using Python Flask and PostgreSQL Database

REST API Login Logout Using Python Flask and PostgreSQL Database

Create table

CREATE TABLE useraccount (

id serial PRIMARY KEY,

username VARCHAR ( 100 ) NOT NULL,

password VARCHAR ( 100 ) NOT NULL

);

Insert data

INSERT INTO useraccount (username, password) VALUES ('tutorial101', 'pbkdf2:sha256:150000$KxxiGerN$4c37a656baa0034035a6be2cd698b5da8b036ae63eef3ab0b08b9c18b9765648');

{"username":"tutorial101","password":"cairocoders"}

Username : tutorial101

password : cairocoders

Testing Rest API

REST API Testing is open-source web automation testing technique that is used for testing RESTful APIs for web applications. The purpose of rest api testing is to record the response of rest api by sending various HTTP/S requests to check if rest api is working fine or not. Rest api testing is done by GET, POST, PUT and DELETE methods.

Rest stands for Representational State Transfer. It is an architectural style and an approach for communication used in the development of Web Services. REST has become a logical choice for building APIs. It enables users to connect and interact with cloud services efficiently.

An API or Application Programming Interface is a set of programming instructions for accessing a web-based software application.

API is a set of commands used by an individual program to communicate with one another directly and use each other's functions to get information.

Install the Advanced Rest Client

1. Go to Google Chrome's Web Store

2. Search for "Advanced Rest Client" https://chrome.google.com/webstore/detail/advanced-rest-client/hgmloofddffdnphfgcellkdfbfbjeloo and Install the extension

 
#app.py
from flask import Flask, jsonify, request, session
from werkzeug.security import generate_password_hash, check_password_hash
from flask_cors import CORS #pip install -U flask-cors
from datetime import timedelta

import psycopg2 #pip install psycopg2 
import psycopg2.extras

app = Flask(__name__)
 
app.config['SECRET_KEY'] = 'cairocoders-ednalan'
 
app.config['PERMANENT_SESSION_LIFETIME'] =  timedelta(minutes=10)
CORS(app) 

DB_HOST = "localhost"
DB_NAME = "sampledb"
DB_USER = "postgres"
DB_PASS = "admin"
    
conn = psycopg2.connect(dbname=DB_NAME, user=DB_USER, password=DB_PASS, host=DB_HOST)  

@app.route('/')
def home():
    passhash = generate_password_hash('cairocoders')
    print(passhash)
    if 'username' in session:
        username = session['username']
        return jsonify({'message' : 'You are already logged in', 'username' : username})
    else:
        resp = jsonify({'message' : 'Unauthorized'})
        resp.status_code = 401
        return resp
 
@app.route('/login', methods=['POST'])
def login():
    _json = request.json
    _username = _json['username']
    _password = _json['password']
    print(_password)
    # validate the received values
    if _username and _password:
        #check user exists          
        cursor = conn.cursor(cursor_factory=psycopg2.extras.DictCursor)
         
        sql = "SELECT * FROM useraccount WHERE username=%s"
        sql_where = (_username,)
         
        cursor.execute(sql, sql_where)
        row = cursor.fetchone()
        username = row['username']
        password = row['password']
        if row:
            if check_password_hash(password, _password):
                session['username'] = username
                cursor.close()
                return jsonify({'message' : 'You are logged in successfully'})
            else:
                resp = jsonify({'message' : 'Bad Request - invalid password'})
                resp.status_code = 400
                return resp
    else:
        resp = jsonify({'message' : 'Bad Request - invalid credendtials'})
        resp.status_code = 400
        return resp
         
@app.route('/logout')
def logout():
    if 'username' in session:
        session.pop('username', None)
    return jsonify({'message' : 'You successfully logged out'})
         
if __name__ == "__main__":
    app.run()