Core Service Written in Go - Services For a Pawn Shop Web Application

Phase 2/2, Im still working on this when I have time

Contributing

Contributions are always welcome!

This project is small, if you want to contribute improving code or add a new feature send a PR, make sure to add a description.

Bussiness Logic

• Administrator

  • Can see all occurred logs into application (sessions, movements and payments).
  • Can see detailed reports by branch office (money recorded, total products, employee statistics, etc).
  • Can manage user access, create new branches, create new employees and create new category products.

• Employee

  • Can manage the category of products
  • Can do pawn orders to customers as well as do endorsements.
  • Can manage the status of pawn orders (in course, overdue, paid or lost)

• Customer

  • Can do multiple pawns, their stuff are evaluated and classified by a category product when a quote is realized.
  • Can do endorsements depending of payment modality (weekly or monthly).
  • The Customer has an extension date of payment depending on the modality
    • Weekly: 1 extra day to make the payment
    • Monthly: 3 extra days to make the payment

• Extras

  • When a customer doesn't make any endorsement after the deadline, all the client's things become property of probien.

Design - Following DDD (Domain Driven Design)

config/
├─ database.go | Connection to postgresql using ORM
├─ redis.go | Connection to redis cloud
|
├─ migrations/
│  ├─ stored procedures | Raw sql/
│  ├─ models | Entity struct that represent mapping to data model/
core/
├─ application | Write business logic/
├─ domain | Entity struct that represent I/O JSON format/
│  ├─ repository | Repository interface for infrastructure/
|
├─ infrastructure/
│  ├─ auth | Middleware and security filters/
│  ├─ persistance | Implements repository interface with database /
|
├─ interface | Expose http endpoints/
router | Routing for endpoints/
server.go

Database Model (subject to change)

Getting started - Manually

Please make sure to download and configure everything below to avoid problems.

Dependencies needed

Gorm (ORM): go get -u gorm.io/gorm

Gin (Framework): go get -u github.com/gin-gonic/gin

Go-Cron (Cron jobs): go get -u github.com/go-co-op/gocron

Go-Redis: go get -u github.com/go-redis/redis/v8

Go-Jwt: go get -u github.com/golang-jwt/jwt/v4

Go-UUID: go get -u github.com/satori/go.uuid

Godotenv: go get -u github.com/joho/godotenv

Environment vars

You must create a .env file called vars.env into the root project, then add the following environment vars:

export PRIVATE_KEY="your private key to sign tokens"

export DATABASE_URI_DEV="your database connection url for development"
export DATABASE_URI_PDN="your database connection url for production"

export REDIS_URI="your redis connection url"
export REDIS_PASSWORD="your redis password"

Example

export PRIVATE_KEY="M¡_$Up3R_s3Cr3t"

export DATABASE_URI_DEV="postgres://postgres:root@locahost:5432/probien?sslmode=disable"
export DATABASE_URI_PDN="postgres://postgres:root@(REMOTE_IP):(REMOTE_PORT)/probien?sslmode=enable"

export REDIS_URI="redis.us-central.cloud.example:12345"
export REDIS_PASSWORD="R3d¡s_P4$$W0rd"

Running the app

If it is the first time you are running the application, you must add the flag obligately, add it after command:

Flag	Type	Description
-migrate	boolean	Migrate datamodel structs and stored procedures to database

go run ./server.go -migrate=true

This will run the server, if you configured everything good, you will see the endpoints display on the console, at this point you can stop the server.

After configure the env vars and migrated the models, run project usually with following command:

go run ./server.go

Getting started - Docker (Image)

Database and service by separately: first build the service image running the following command

docker build -t probien-core:1.0 .  

Next, create the database container (postgres) by exposing the host machine's ports to the container.

docker run --name probien-database -p 5432:5432 -e POSTGRES_PASSWORD=root -e POSTGRES_DB=probien -d postgres

Finally, we need to create the container service from the image that we recently build:

docker run --name probien-core -p 9000:9000  probien-core:1.0

Getting started - Docker (Compose)

To pull up a complete environment, you can do via compose

docker compose up

In case you need remove the environment, just hit

docker compose down

Note: the docker compose pulls up the probien backend service, a redis server for store sessions and a postgres database