password-checker

Read the accompanying blog post about this project: Would you hire ChatGPT?

Password Strength Checker

The Password Strength Checker is a command-line and HTTP-based service written in Go that checks the strength of a password based on certain rules. It is built to be production-ready with operational features including health checks, metrics, Docker support, and load testing configuration.

Functional Requirements

The application checks if a password is strong based on the following criteria:

• It has at least 6 characters and at most 20 characters.
• It contains at least one lowercase letter, at least one uppercase letter, and at least one digit.
• It does not contain three repeating characters in a row (i.e., "aaa").

Features

Command-line Interface

You can use the password checker in the command-line with a simple input password.

HTTP Interface

The password checker can also be run as a HTTP server that takes in password as a parameter and returns the steps required to make it strong.

Health Check Endpoint

The HTTP server also includes a /healthcheck endpoint that returns a 200 success HTTP status value.

Metrics Endpoint

The HTTP server includes a /metrics endpoint that exposes Prometheus metrics. It currently tracks the total number of requests made to the password strength check endpoint.

Docker Support

This service can be built and run as a Docker container using the provided Dockerfile and docker-compose.yml files.

Load Testing Configuration

A k6 configuration file (loadtest.js) is provided for load testing the HTTP password checker web service.

Task Runner

A Go-Task Taskfile.yml is provided for automation of common tasks like running tests, building the application, and more.

Logging

The HTTP service logs each request made, with adjustable log level setting to control the verbosity of the logs.

Usage

CLI

Run go run main.go <password> to check the strength of <password>.

HTTP server

Run go run main.go -d to start the HTTP server. You can then send a GET request to localhost:8080/check/<password> to check the strength of <password>.

Build

You can use Docker Compose to build and run the service:

docker-compose up --build

Test

Unit tests can be run with the Go test command:

go test

Task Runner

You can use the Go-Task task runner to automate common tasks. For example, to run tests:

task test

Load Testing

You can use k6 for load testing. First install k6, then run:

k6 run loadtest.js