Golang REST Api with Postgres and Docker

This is a simple Go Api that exposes only one endpoint /profiles.

My main goal with this project was to learn how to integrate a Gin project with Postgres database and run them together using Docker Compose. I've used Gorm package since it's a great ORM library writed in Go, that implements Pgx driver for postgres.

Packages used in this project

• Gin
• Gorm

Project folder structure

The project entry point is in cmd/main.go.

.
└── project/
    ├── cmd
    │   └── main.go
    ├── out/
    │   └── "final app"
    ├── pkg/
    │   ├── common/
    │   │   ├── db/
    │   │   │   └── db.go
    │   │   ├── env/
    │   │   │   └── env.go
    │   │   └── models/
    │   │       └── profile.go
    │   └── profile/
    │       ├── add_profile.go
    │       ├── controller.go
    │       ├── delete_profile.go
    │       ├── get_profile.go
    │       ├── get_profiles.go
    │       └── update_profile.go
    ├── .env
    ├── docker-compose.yml
    ├── Dockerfile
    ├── go.mod
    ├── go.sum
    ├── Makefile
    └── README.md

The Dockerfile

Following best practices, I've created the server's Dockerfile to be run in two steps:

1. Create an image, copying the project's files and building the server application
2. Create a fresh Alpine Linux image and copying the built project into it.

## Dockerfile
FROM golang:1.19-alpine AS build_base

RUN apk add --no-cache git
RUN apk add --update make

WORKDIR /tmp/golang-restApi-with-docker

COPY go.mod .
COPY go.sum .

RUN go mod download

COPY . .

RUN make build

# Create a new fresh image, and optmize the size of the application
FROM alpine:3.9
RUN apk add ca-certificates

COPY --from=build_base /tmp/golang-restApi-with-docker/out/golang-restApi-with-docker /app/golang-restApi-with-docker

EXPOSE 8080

CMD ["./app/golang-restApi-with-docker"]

That way, the final container created by the image has approximately 27 MB.

Prerequisites

• make
• docker
• docker-compose

You also need to create a .env file at the root directory with some configurations to be loaded when the Docker Compose run, specially user and password to create the Database. See the following example:

## .env
# Server configuration
PORT=":8080"
DB_URL="postgres://USER:PASSOWRD@db:5432/postgres"

# DataBase configuration
POSTGRES_USER="USER"
POSTGRES_PASSWORD="PASSOWRD"

The same USER and PASSWORD you use for postgres needs to inserted into the DB_URL variable.

Running the project

Running using make:

make docker

Running using docker-compose:

docker-compose up -d --build

In both cases, you should see something like this when running docker ps command in terminal:

CONTAINER ID   IMAGE                      COMMAND                  CREATED          STATUS         PORTS                                       NAMES
363b3388e55e   go-databases-server        "./app/golang-restAp…"   56 minutes ago   Up 8 seconds   0.0.0.0:8080->8080/tcp, :::8080->8080/tcp   golang-server
4a8bbd2b9e99   postgres:14.5-alpine3.16   "docker-entrypoint.s…"   56 minutes ago   Up 7 seconds   0.0.0.0:5432->5432/tcp, :::5432->5432/tcp   go-databases-db-1

Endpoints

Method	Endpoint	Description
GET	"/profiles/"	Get all the profiles
GET	"/profiles/:id"	Get profile by ID
POST	"/profiles/"	Create new profile
PUT	"/profiles/:id"	Update an existing profile
DELETE	"/profiles/:id"	Delete the profile using ID