MVC REST API and ORM Go Template

Inspired by go-gin-boilerplate for:

1. Swagger
2. Gin
3. Modular approach in go (no gorm dependency of controllers)

Have a template for starting a REST API with ORM integration and hot reload with go air.

Run Environments

Setup 3 environments: dev, stage and prod

Run Dev Environment

Run DB (terminal 1)

1. cd docker/dev
2. docker compose up

Enter PostgreSQL DB (terminal 2)

1. docker exec -it dev-db-1 bash
2. su - postgres
3. psql -h localhost -p 5432 -U <db_name>
4. psql -h localhost -p 5432 -U postgres postgres
5. \l : list DBs
6. \c <db_name> : connect to DB
7. \dt : list all the tables
8. select * from <table_name>;
9. select * from users;

Run Go REST API Service (terminal 3)

1. cd <project_root>
2. SERVER_ENVIRONMENT="dev" go run main.go

REST API

Uses Gin-Gonic

ORM

Uses GORM

Format Code

1. cd ~/go/src/github.com/pavva91/gin-gorm-rest/
2. gofmt -l -s -w .

Hot Reload (air)

Go Air enables hot reloading in go. Usage of air:

1. Create of config file (.air.toml):
   • air init
2. Run app with hot reload (inside project root):
   • air Instead of:
   • go run main.go
   • go run main.go server_config.go

JWT Authentication

Tutorial: https://codewithmukesh.com/blog/jwt-authentication-in-golang/ Check JWT token decoder Dependencies:

• go get github.com/dgrijalva/jwt-go (deprecated)
• go get -u github.com/golang-jwt/jwt/v5 (up to date)
• go get golang.org/x/crypto/bcrypt

1. Authenticate (create JWT token for the user account):

• curl -X POST http://127.0.0.1:8080/api/v1/token -d '{"email":"[email protected]", "password":"1234"}' Response: { "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VybmFtZSI6ImFsaWNlODkiLCJlbWFpbCI6ImFsaWNlQGdtYWlsLmNvbSIsImV4cCI6MTY4MDI2MDU2OH0.6d9-WiCQTAcs4wxIkqHyQ3J0-UZBEr2_swpdUcO7zRc" }

2. Authorized Call:

• curl -X GET http://127.0.0.1:8080/api/v1/secured/ping -H 'Accept: application/json' -H 'Authorization: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VybmFtZSI6ImFsaWNlODkiLCJlbWFpbCI6ImFsaWNlQGdtYWlsLmNvbSIsImV4cCI6MTY4MDI2MDU2OH0.6d9-WiCQTAcs4wxIkqHyQ3J0-UZBEr2_swpdUcO7zRc'

Config YAML

Uses Clean Env:

• go get -u github.com/ilyakaznacheev/cleanenv

Swagger Docs (Swag)

Uses Swag

• go install github.com/swaggo/swag/cmd/swag@latest Note: Go install tries to install the package into $GOBIN, when $GOBIN=/usr/local/go/bin will not work, works with $GOBIN=~/go/bin Initialize Swag (on project root):
• swag init Then get dependencies:
• go get -u github.com/swaggo/gin-swagger
• go get -u github.com/swaggo/files

Format Swag Comments:

• swag fmt

Swagger API:

• http://localhost:8080/swagger/index.html#/

Error Handling

Inspired by:

• https://blog.depa.do/post/gin-validation-errors-handling

Logging

Zero allocation JSON logger, zerolog:

• go get -u github.com/rs/zerolog/log

Go Validator

Gin uses [Go Validator v10] (https://github.com/go-playground/validator):

• go get github.com/go-playground/validator/v10

In code import:

• import "github.com/go-playground/validator/v10"

Unit Tests

• go get -u github.com/stretchr/testify
• Run all tests: go test ./...
• Run all tests and create code coverage report: go test -v -coverprofile cover.out ./...
• Run all tests with code coverage and open on browser: go test -v -coverprofile cover.out ./... && go tool cover -html=cover.out
• Run tests of /controllers with code coverage and open on browser: go test -v -coverprofile cover.out ./controllers/ && go tool cover -html=cover.out
• Run specific tests (regex): go test -run TestMyFunction ./...
• Run specific tests (regex): go test -run Test_GenerateToken_InvalidRequestBodyNoPasswordField_400BadRequest ./...
• Run specific tests (regex) of a module (e.g. controllers): go test -run Test_GenerateToken ./controllers
• Run tests of a folder (e.g. validation): go test ./validation
• Run tests of a module (e.g. validation): go test github.com/pavva91/gin-gorm-rest/validation
• Run particular test (e.g. test Test_GetByID_EmptyId_400BadRequest in /controllers/user_test.go): go test -v ./... -run Test_GetByID_EmptyId_400BadRequest
• Run particular test (e.g. test Test_GetByID_EmptyId_400BadRequest in /controllers/user_test.go): go test -v ./controllers -run Test_GetByID_EmptyId_400BadRequest
• Run particular test with code coverage report (e.g. test Test_GetByID_EmptyId_400BadRequest in /controllers/user_test.go): go test -v -coverprofile cover.out ./controllers -run Test_GetByID_EmptyId_400BadRequest && go tool cover -html=cover.out
• Run particular test when using test suite (e.g. test Test_Status_Return200 in TestSuiteHealthController in /controllers/health_test.go): go test -v ./controllers -run TestSuiteHealthController -testify.m Test_Status_Return200

Code Structure to enable Unit Tests (testeable code)

• Code samples

Code Coverage

• By package name:

  • Just run: go test -cover github.com/pavva91/gin-gorm-rest/validation
  • Create coverage file: go test -v -coverprofile cover.out github.com/pavva91/gin-gorm-rest/validation
  • One Command create coverage file and open in browser; go test -v -coverprofile cover.out github.com/pavva91/gin-gorm-rest/controllers && go tool cover -html=cover.out

• By folder:

  • Just run: go test -cover ./validation
  • Create coverage file: go test -v -coverprofile cover.out ./validation
  • Open coverage file on browser: go tool cover -html=cover.out
  • One Command create coverage file and open in browser; go test -v -coverprofile cover.out ./controllers/ && go tool cover -html=cover.out

• Run all tests:

  • Just run: go test ./... -cover
  • Create coverage file: go test ./... -coverprofile coverage.out
  • Open coverage file on browser: go tool cover -html=coverage.out

From stack overflow

1. Create function in ~/.bashrc and/or ~/.zshrc:

cover () {
  t="/tmp/go-cover.$$.tmp"
  go test -coverprofile=$t $@ && go tool cover -html=$t && unlink $t
}

2. Call this function:

• cd ~/go/src/github.com/pavva91/gin-gorm-rest/
• cover github.com/pavva91/gin-gorm-rest/validation

Run Unit Test with Debugger

• :lua require('dap-go').debug_test()
• Keymap: dt

cURL Calls

• List users: GET /users:
  • curl -X GET http://127.0.0.1:8080/users
• Create user: POST /users:
  • curl -X POST http://127.0.0.1:8080/users -H 'Content-Type: application/json' -d '{"name":"mario", "email":"[email protected]", "password":"1234"}'
• Get a user: GET /users/1:
  • curl -X GET http://127.0.0.1:8080/users/1
• Modify a user: PUT /users/1:
  • curl -X PUT http://127.0.0.1:8080/users/1 -H 'Content-Type: application/json' -d '{"name":"john", "email":"[email protected]", "password":"5678"}'
• Delete a user: DELETE /users/1:
  • curl -X DELETE http://127.0.0.1:8080/users/1