Introduction 👋

Password Generator REST API leverages AWS Lambda proxy integration and AWS API Gateway to generate a strong password (not less than 8 characters) on each API request. The API user may specify the length of the desired password. A Python function on AWS Lambda generates the password using a combination of upper case, lower case, numbers and special characters.

Project Demo 🎥

Objectives 😇

• Create a password-generating Lambda function for the API backend.
• Create and test a Password Generator API with Lambda proxy integration.

Prerequisites 📌

• AWS IAM user account with management console access.
• Postman

The Development 💻 💻

Create Password Generator AWS Lambda Function

The Lambda function returns the JSON response for a request with a valid password length:

{
    "Your password is: " + password + " Thanks for using the Password Generator"
}

The Lambda function returns the JSON response for a request with an invalid password length:

{
    "Your password must have at least 8 characters"
}

• Open Lambda service on the AWS Management Console. Ensure that you are signed into your IAM user account. I am using US East (N. Virginia) us-east-1 region. Click on Functions on the left side panel and click on Create Function.
• Select Author from scratch. In Basic information, set the Function name as PasswordGeneratorLambdaProxyIntegration. Select Python 3.9 as the function's language.
• In Permissions, open Change default execution role dropdown. Select Create a new role from AWS policy templates. Set the role name as PasswordGeneratorLambdaBasicExecutionRole.
• Click Create Function.

• Copy/paste the python code below into code editor

import json
import random
import string

def lambda_handler(event, context):

    print("Welcome to Password Generator")

    # Set the password length with constraints for the password length
    password_length = int(event['queryStringParameters']['length'])
    if password_length < 8:
        return {
        'statusCode': 200,
        'body': json.dumps('Your password must have at least 8 characters.')
    }
    else:
        # define the characters
        lower = string.ascii_lowercase
        upper = string.ascii_uppercase
        num = string.digits
        symbols = string.punctuation

        all_characters = lower + upper + num + symbols

        # generate a password string
        temp = random.sample(all_characters, password_length)
        password = "".join(temp)    

        return {
        'statusCode': 200,
        'body': json.dumps("Your password is: " + password + " Thanks for using the Password Generator")
    }

• Click Deploy

Create Password Generator API

• Open the AWS API Gateway console.
• Select Create API. Select a type of API. For this project, we are using a public REST API. Select Build.
• Set the API name as PasswordGeneratorLambdaSimpleProxy and then click Create API.
• In Resources on the left-hand panel, Create Resource for the root / of the API under Actions. Set the Resource Name as generatepassword.
• Select /generatepassword from the resource list. Click Actions. Click Create Method. Select ANY and click on the checkmark.
• Select Use Lambda Proxy integration. Type in characters in Lambda Function text box. This generates a dropdown of your Lambda functions. Select PasswordGeneratorLambdaProxyIntegration.
• Click Save.

  API Testing on Postman

• Select Deploy API under Actions.

• Set the stage name as test.

• Click Deploy.

• Copy the invoke URL and paste it on Postman for testing. Include the name of the resource on the URL. Set the query parameters for the password length.

References 📙

• Tutorial: Build a Hello World REST API with Lambda proxy integration

Conclusion 🔚

Test the project URL using the web browser as well. Set the appropriate query parameter for the password length. y5r9r96qdc.execute-api.us-east-1.amazonaws...

Comments, questions or suggestions related to this tutorial? Please share them with me. I'll be delighted to hear from you.

Cheers! 🎊 🍻 🎊 🍻 🎊 🍻