NAB-challenge

High-level solution diagram

The project is designed and developed with monorepo architecture.

Two services are developed to demonstrate the backend APIs:

• Shop service: manages products, variants.
• History service: saves user's activities.

Depending on the requests, the Shop service may call the History service to save user's activities.

The website and internal web apps are supposed to developed also within this architecture.

Sequence diagrams

The challenge is implemented with 4 scenarios:

• The user goes to a product listing page to view all products
• The user clicks on a product to go to the product page
• The user searches for products by typing a keyword
• The sale/marketing staff views historical activities of a user via the Sales/Marketing web app.

The followings are sequence diagrams of the 4 use-cases.

User views all products

User views a product

User searches for products

Marketing/sale views historical activities of a user

Entity relationship diagrams

• The project is designed with micro service principles.
• Each service has its own database and communicate via REST APIs.
• Tables and fields in each diagram are defined with basic data and relationships.

Shop service

History service

Software development principles, patterns & practices

Architecture

• Monorepo
• Micro services

Pattern

• Functional programming

Practices

• Testing: unit, integration
• CI : build with github actions

Code folder structure and the libraries / frameworks being used

The project is structured with two main folders:

• services: contains all backed services, i.e. shop and history
• packages: contains libraries that are shared between services, concretly:
  • db: manages db connection and query
  • http: manages backend servers and middlewares
  • logger: provides logging feature for dev and production mode

project
│    README.md
│    LICENSE
|    package.json
│
└─── packages
│    │
│    └─── db
|    |
│    └─── http
|    |
│    └─── logger
|
└─── services
     |
     └─── history
     |
     └─── shop

The project is developed with typescript. Main framework/libraries are used:

• koajs
• pg
• ts-node
• jest
• mocha
• chai
• sinon
• supertest
• nodemon

Formatters for code and git commit:

• eslint
• prettier
• husky
• commitlint

Steps to get the applications run on local

Prepare database

Make sure that Postgresql is installed and run.

If you want to run Postgresql by docker, you could use:

docker run --rm --name pg-docker -e POSTGRES_PASSWORD=yourpassword -d -p 5432:5432 -v $HOME/docker/volumes/postgres:/var/lib/postgresql/data postgres:12

psql -h localhost -p 5432 -U postgres
(type: yourpassword)

Create shop database and seed data

Create database and grant privileges for db user.

Information of the database and db user must be matched with data declared in services/shop/.env

CREATE DATABASE nab_shop;

CREATE USER goku WITH ENCRYPTED PASSWORD 'nimbuscloud';

GRANT ALL PRIVILEGES ON DATABASE nab_shop TO goku;

Database of shop is prepared in the databases/shop.sql. You may need to restore them to have some data for testing.

The database is prepared with 145 colors, 86 sizes, 20 products and 100 variants

Command to restore DB:

pgsql -U goku -d nab_shop < shop.sql

If you run Postgresql by docker, the restore command would be:

cat shop.sql | docker exec -i pg-docker psql -U goku -d nab_shop

Create history database

Information of the database and db user must be matched with data declared in services/history/.env

CREATE DATABASE nab_history;

CREATE USER chichi WITH ENCRYPTED PASSWORD 'helmet';

GRANT ALL PRIVILEGES ON DATABASE nab_history TO chichi;

Database of history is prepared in the databases/history.sql with 50 users and 4 activity types.

To restore the history DB:

psql -U chichi -d nab_history < history.sql

If you run Postgresql by docker:

cat history.sql | docker exec -i pg-docker psql -U chichi -d nab_history

Clone code and run

Clone the code from this repository and install packages.

git clone [email protected]:chan-nguyen/nab-challenge.git

cd nab-challenge

yarn install

Start the shop service

yarn workspace shop start

The shop service should be running at http://localhost:8080

Open another terminal, start the history service

yarn workspace history start

The history service should be running at http://localhost:8090

CURL commands to verify APIs

The followings are some examples of CURL commands. You are free to change the search string or the Id of user and variant for testing.

List products

curl 'http://localhost:8080/products --header 'user-id: 1'

Search for products

curl 'http://localhost:8080/products?s=ca' --header 'user-id: 1'

curl 'http://localhost:8080/products?s=metal' --header 'user-id: 2'

Get product variant

curl 'http://localhost:8080/variants/17' --header 'user-id: 1'

curl 'http://localhost:8080/variants/22' --header 'user-id: 1'

Get user activities

curl 'http://localhost:8090/users/1/activities'

curl 'http://localhost:8090/users/2/activities'