valverdethiago / wallet-hub-java-mysql-test

Wallet HUB - Java and MySQL Test

The goal of this project is provide a complete solution for the proposed assignment for the Senior Backend Engineer for WalletHub.

Structure

• Problem Statement
• Deliverables:
  • Java program that can be run from command line - parser
  • Source Code for the Java program - Parser project
  • MySQL schema used for the log data - SQL folder
  • SQL queries for SQL test
    1. Write MySQL query to find IPs that mode more than a certain number of requests for a given time period
    2. Write MySQL query to find requests made by a given IP

General explanation

A spring-boot application was built to solve the problem. Using spring-data to access the mysql database to manipulate two entities responsibles to handle all the data requirements:

• BlockedIp - Entity that stores the blocked ips
• HttpAccess - Entity that stores all the log entries provided via access.log file

Project structure:

The application classes structure is summarized by the following package division:

• model - Stores all entities and related classes, such Duration enumeration and InputPArametersDto to deliver all the input parameters to the services;
• repository - Stores the repositories for the two JPA entities;
• runner - Has only the CommandLineRunner class responsible to handle all the parameters passed via CommandLine
• service - Has the services responsible to parsing the access log files, implement validation rules and the business logic to find the correct ips and block them.

Parametrization

The application is built to be executed with the following command:

java -jar ./dist/parser.jar --accesslog=./access.log 
    --startDate=2017-01-01.15:00:00 --duration=hourly --threshold=200

It's not needed to pass the main class to be executed as spring maven plugin sets this on jar manifest file.

There are a few attributes configured under application.properties that can be customized via environment variables:

Environment Variable Name	Defaul Value
DB_HOST	localhost
DB_PORT	3306
DB_NAME	http_access
DB_USERNAME	admin
DB_PASSWORD	admin

Database creation

If we set an user with enought grant on the database the application should be able to create the database if it does not exists.

Build

To build the application from scratch run the following command under the parser folder:

mvn package

This command will build the code, run the unit tests and package the application into a file under dist folder called parser.jar.