Sneaker Shop 👟

A back-end web development project.

Table of contents

• Sneaker Shop
  • Idea
  • Tech Stack
• Environment Setup
  • Maven
  • Docker
  • Postgres
  • Redis
  • Database Connection
  • Database Migration
• CI/CD
  • GitHub
  • Unit Test
  • Packaging
  • Build Docker Image
  • Containerized App

Idea

Imagine walking into a sneaker shop and seeing hundreds of sneakers displaying in front of you.

There are so many factors you need to consider: size style brand color material...

How do you choose the perfect pair?

SneakerShop is a system that takes in all the factors into account and chooses the perfect sneaker for you.

Tech Stack

Database : PostgreSQL
Testing : JUnit Mockito
Frameworks : Spring-boot Hibernate
Cloud Deployment : AWS S3 AWS SQS
Tools : Git Docker Maven Flyway pgAdmin Postman Redis

Environment Setup

These instructions will help you setup the environment that the project is based on.

Maven

Use Maven to manage the project.

Maven is a software project management and comprehension tool.

It manages a project's dependencies and helps with build automation.

All the dependencies and plugins are in the pom.xml file.

Docker

Docker uses OS-level virtualization to deliver software in packages called container.

List all Docker images and containers:

docker images
docker ps -a

Pull images:

docker pull <image_name>

Restart an exited container:

docker start <container_name>

Postgres

Use PostgreSQL container as database server.

Pull image from postgres and run container:

docker pull postgres
docker run --name <container_name> -e POSTGRES_DB=<server_name> 
-e POSTGRES_USER=admin -e POSTGRES_PASSWORD=password -p 5432:5432 -d postgres

Redis

Use Redis to enable caching for better controller performance.

Pull image from redis and run container:

docker pull redis
docker run -p 6379:6379 --name spring-redis -d redis

Enter interactive terminal:

docker exec -it spring-redis /bin/bash 

Redis commandline:

redis-cli keys *
redis-cli FLUSHDB
redis-cli info stats | grep 'keyspace_*'

Database Connection

Use JVM Option to create database connection.

-Ddatabase.user=${user_name}
-Ddatabase.password=${password}
-Ddatabase.driver=org.postgresql.Driver
-Ddatabase.dialect=org.hibernate.dialect.PostgreSQL9Dialect
-Ddatabase.url=jdbc:postgresql://${database_url}:${port}/${database_name}

Database Migration

Use Flyway as a data migration tool.

Flyway is a Maven plugin, it makes database migrations easy.

mvn clean compile flyway:migrate -Ddatabase.url=...

CI/CD

You should have completed the following stages before you work with DevOps engineer.

• Upload source code to GitHub repository
• Fulfill unit test stage in docker container
• Package .war file in docker container
• Build Docker image with .war file and Dockerfile
• Launch containerized application successfully

GitHub

Make sure you have uploaded the latest version of your source code in a public GitHub repository.

*Don't include any credential or database information in your source code.

Unit Test

Use Docker to pull Maven image and run an interactive container.

docker pull maven:3.6.0-jdk-8
docker run -it maven:3.6.0-jdk-8 /bin/bash

Use Git to retrieve source code from GitHub.

git clone <repository_url>

Switch to the project folder, then use Flyway to migrate data.

mvn clean compile flyway:migrate -Ddatabase.url=jdbc:postgresql://${database_url}:5432/${database_name} 
-Ddatabase.user=${user_name} -Ddatabase.password=${password}

Notice: we are working in a maven container so the database connection is no longer through localhost:5432. The database_host should be the internal IP address for the postgreSQL server container. Find the internal IP address of the container by using:

docker inspect ${container_id} | grep "IPAddress"

Run unit tests in the container.

mvn test -Ddatabase.url=jdbc:postgresql://${database_url}:5432/${database_name} -Ddatabase.user=${user_name} 
-Ddatabase.password=${password} -Daws.accessKeyId=${access_key} -Daws.secretKey=${secret_key} 
-Ddatabase.dialect=org.hibernate.dialect.PostgreSQL9Dialect -Ddatabase.driver=org.postgresql.Driver

Packaging

Use Maven to package a .war file.

mvn compile package -DskipTests=true -q

Build Docker Image

Build your image with Dockerfile (including environment variables like DB_URL, DB_PASSWORD), setenv.sh (use environment variables as JVM options) and .war file.

Run Containerized App

Launch a containerized application in your local machine.

docker run -e ENV_VAR=VAL ${IAMGE_ID}