📝 Summary

Goliath is an opinionated set of libraries to build resilient, scalable and maintainable applications. The goal of these libraries is to allow focusing on building applications instead of reinventing the wheel.

🚀 Features

• app - set of common utilities such as elegant errors and enriched ctx.Context
• retry - retry a specific task securely
• clock - wrapper around time.Now to help during testing
• sleep - wrapper around time.Sleep for testing
• httperror - implementation of the RFC7807 Problem Details

👀 Examples

app

// create elegant application errors
err := app.NewErrorValidation("validate_user", "Error Validating User")
err.AddValidationError(NewFieldValidationError("name", "name is empty"))
err.AddValidationError(NewFieldValidationError("age", "user is under 18", "user must be an adult"))

// wrap the inner cause of the error
conn, err := db.Connect(...)

if err != nil {
   return app.NewErrorInternal("database_connection", "Error connecting to the database").SetSeverity(app.ErrorSeverityCritical).Wrap(err)
}

// create a raw error
err := app.NewError(("error_code", app.ErrorInternal, app.ErrorSeverityHigh, "Error message"))

// enriched context
func Hello(w http.ResponseWriter, r *http.Request) {
    ctx := app.FromContext(r.Context())
    traceId := appCtx.TraceID()
    userID, checkUser := ctx.UserID()

    if checkUser {
        //request authorized
    }
}

retry

	var GetPersonTask = func() (Person, error) {
        var p Person
        resp, err := http.Get("http://example.com/")

        if err != nil {
            return p, err
        }

        err = json.NewDecoder(resp.Body).Decode(&p)

		return resp, err
	}

    config := retry.NewConfig(3)

	result, err := retry.Execute(config, task)

clock

	clock := NewUtcClock()
	timeNowUtc := clock.Now().Format(time.RFC822)

sleep

	sleeper := sleep.New()
	sleeper.Sleep(1000)

httperror

	appCtx := app.FromContext(ctx)
	err := app.NewErrorValidation("invalid_payment_data", "The payment request is invalid")
	err.AddValidationError(app.NewFieldValidationError("amount", "Amount needs to be positive"))
	err.AddValidationError(app.NewFieldValidationError("currency", "currency is required"))

	httpErr := New(appCtx, err, "/payments")

Problem Detail Output

{
  "type": "invalid_payment_data",
  "title": "The payment request is invalid",
  "status": 400,
  "instance": "/payments",
  "traceId": "9b1b4579-b455-4eed-ac80-923668593dcc",
  "errors": {
    "amount": ["Amount needs to be positive"],
    "currency": ["currency is required"]
  }
}