not tested

Makefile

@@ -21,3 +21,6 @@ check-build:
 
 clean:
 	rm -rf $(BINDIR)
+
+run: check-build
+	$(BIN)

cmd/go-jsonapi-example/main.go

@@ -17,20 +17,51 @@ import (
 	"fmt"
 	"net/http"
 
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+
 	"go-jsonapi-example/internal/model"
 	"go-jsonapi-example/internal/resource"
 	"go-jsonapi-example/internal/storage"
 
 	"github.com/manyminds/api2go"
+
+	"github.com/juju/gnuflag"
 )
 
 func main() {
-	port := 8080
-	baseURL := fmt.Sprintf("http://localhost:%d", port)
-	api := api2go.NewAPIWithBaseURL("v1", baseURL)
-	carStorage := storage.NewCarStorage()
-	api.AddResource(model.Car{}, resource.CarResource{CarStorage: carStorage})
+	host := gnuflag.String("host", "localhost", "host")
+	port := gnuflag.Int("port", 8080, "port")
+	gnuflag.Parse(true)
 
-	fmt.Printf("Listening on :%d", port)
-	http.ListenAndServe(fmt.Sprintf(":%d", port), api.Handler())
+	addr := fmt.Sprintf("%s:%d", *host, *port)
+	baseURL := fmt.Sprintf("http://%s", addr)
+
+	api := api2go.NewAPIWithBaseURL("v1", baseURL)
+	api.AddResource(model.Car{}, resource.CarResource{CarStorage: storage.NewCarStorage()})
+
+	server := &http.Server{Addr: addr, Handler: api.Handler()}
+	closeHandler(server)
+
+	fmt.Printf("Listening on %s\n", addr)
+	if err := server.ListenAndServe(); err != http.ErrServerClosed {
+		fmt.Printf("error: %s\n", err)
+		os.Exit(1)
+	} else {
+		fmt.Println(err)
+		os.Exit(0)
+	}
+}
+
+func closeHandler(server *http.Server) {
+	interrupt := make(chan os.Signal, 1)
+	signal.Notify(interrupt, os.Interrupt, syscall.SIGTERM)
+	go func() {
+		<-interrupt
+		if err := server.Shutdown(context.Background()); err != nil {
+			fmt.Printf("error: %s\n", err)
+		}
+	}()
 }

go.mod

@@ -4,5 +4,6 @@ go 1.14
 
 require (
 	github.com/gorilla/mux v1.8.0 // indirect
+	github.com/juju/gnuflag v0.0.0-20171113085948-2ce1bb71843d
 	github.com/manyminds/api2go v0.0.0-20210211132652-5457038544fa
 )

go.sum

@@ -28,6 +28,8 @@ github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/json-iterator/go v1.1.9 h1:9yzud/Ht36ygwatGx56VwCZtlI/2AD15T1X2sjSuGns=
 github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
+github.com/juju/gnuflag v0.0.0-20171113085948-2ce1bb71843d h1:c93kUJDtVAXFEhsCh5jSxyOJmFHuzcihnslQiX8Urwo=
+github.com/juju/gnuflag v0.0.0-20171113085948-2ce1bb71843d/go.mod h1:2PavIy+JPciBPrBUjwbNvtwB6RQlve+hkpll6QSNmOE=
 github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/labstack/echo v3.3.10+incompatible h1:pGRcYk231ExFAyoAjAfD85kQzRJCRI8bbnE7CX5OEgg=

internal/model/model_car.go

@@ -3,6 +3,9 @@ package model
 import (
 	"errors"
 
+	"net/http"
+
+	"github.com/manyminds/api2go"
 	"github.com/manyminds/api2go/jsonapi"
 )
 
@@ -10,47 +13,97 @@ type Car struct {
 	ID     string `json:"-"`
 	Brand  string `json:"brand"`
 	Model  string `json:"model"`
-	Price  uint   `json:"price"`
-	Status string `json:"status"`
+	Price  uint64 `json:"price"`
+	Status string `json:"status"` // OnTheWay, InStock, Sold, Discontinued
+}
+
+func (c Car) Verify() (bool, api2go.HTTPError) {
+	var verifyErrors []api2go.Error
+	var httpError api2go.HTTPError
+
+	if c.Brand == "" {
+		newErr := newVerifyError(
+			"Invalid Attribute",
+			"attribute cannot be empty",
+			"/data/attributes/brand")
+		verifyErrors = append(verifyErrors, newErr)
+	}
+	if c.Model == "" {
+		newErr := newVerifyError(
+			"Invalid Attribute",
+			"attribute cannot be empty",
+			"/data/attributes/model")
+		verifyErrors = append(verifyErrors, newErr)
+	}
+	if c.Status != "OnTheWay" &&
+		c.Status != "InStock" &&
+		c.Status != "Sold" &&
+		c.Status != "Discontinued" {
+		newErr := newVerifyError(
+			"Invalid Attribute",
+			"attribute must be one of: OnTheWay, InStock, Sold, Discontinued",
+			"/data/attributes/brand")
+		verifyErrors = append(verifyErrors, newErr)
+	}
+
+	ok := len(verifyErrors) == 0
+
+	if !ok {
+		httpError := api2go.NewHTTPError(
+			errors.New("Invalid content"),
+			"Invalid content",
+			http.StatusBadRequest)
+		httpError.Errors = verifyErrors
+	}
+
+	return ok, httpError
+}
+
+func newVerifyError(title string, detail string, pointer string) api2go.Error {
+	var newError api2go.Error
+	newError.Title = title
+	newError.Detail = detail
+	newError.Source = &api2go.ErrorSource{Pointer: pointer}
+	return newError
 }
 
 // GetID to satisfy jsonapi.MarshalIdentifier interface
-func (u Car) GetID() string {
-	return u.ID
+func (c Car) GetID() string {
+	return c.ID
 }
 
 // SetID to satisfy jsonapi.UnmarshalIdentifier interface
-func (u *Car) SetID(id string) error {
-	u.ID = id
+func (c *Car) SetID(id string) error {
+	c.ID = id
 	return nil
 }
 
 // GetReferences to satisfy the jsonapi.MarshalReferences interface
-func (u Car) GetReferences() []jsonapi.Reference {
+func (c Car) GetReferences() []jsonapi.Reference {
 	return []jsonapi.Reference{}
 }
 
 // GetReferencedIDs to satisfy the jsonapi.MarshalLinkedRelations interface
-func (u Car) GetReferencedIDs() []jsonapi.ReferenceID {
+func (c Car) GetReferencedIDs() []jsonapi.ReferenceID {
 	return []jsonapi.ReferenceID{}
 }
 
 // GetReferencedStructs to satisfy the jsonapi.MarhsalIncludedRelations interface
-func (u Car) GetReferencedStructs() []jsonapi.MarshalIdentifier {
+func (c Car) GetReferencedStructs() []jsonapi.MarshalIdentifier {
 	return []jsonapi.MarshalIdentifier{}
 }
 
 // SetToManyReferenceIDs sets the sweets reference IDs and satisfies the jsonapi.UnmarshalToManyRelations interface
-func (u *Car) SetToManyReferenceIDs(name string, IDs []string) error {
+func (c *Car) SetToManyReferenceIDs(name string, IDs []string) error {
 	return errors.New("There is no to-many relationship with the name " + name)
 }
 
 // AddToManyIDs adds some new sweets that a users loves so much
-func (u *Car) AddToManyIDs(name string, IDs []string) error {
+func (c *Car) AddToManyIDs(name string, IDs []string) error {
 	return errors.New("There is no to-many relationship with the name " + name)
 }
 
 // DeleteToManyIDs removes some sweets from a users because they made him very sick
-func (u *Car) DeleteToManyIDs(name string, IDs []string) error {
+func (c *Car) DeleteToManyIDs(name string, IDs []string) error {
 	return errors.New("There is no to-many relationship with the name " + name)
 }

internal/resource/resource_car.go

@@ -122,6 +122,10 @@ func (s CarResource) Create(obj interface{}, r api2go.Request) (api2go.Responder
 		return &Response{}, api2go.NewHTTPError(errors.New("Invalid instance given"), "Invalid instance given", http.StatusBadRequest)
 	}
 
+	if ok, httpErr := car.Verify(); !ok {
+		return &Response{}, httpErr
+	}
+
 	id := s.CarStorage.Insert(car)
 	car.ID = id
 
@@ -141,6 +145,10 @@ func (s CarResource) Update(obj interface{}, r api2go.Request) (api2go.Responder
 		return &Response{}, api2go.NewHTTPError(errors.New("Invalid instance given"), "Invalid instance given", http.StatusBadRequest)
 	}
 
+	if ok, httpErr := car.Verify(); !ok {
+		return &Response{}, httpErr
+	}
+
 	err := s.CarStorage.Update(car)
-	return &Response{Res: car, Code: http.StatusNoContent}, err
+	return &Response{Code: http.StatusOK}, err
 }

internal/resource/response.go

@@ -8,9 +8,7 @@ type Response struct {
 
 func (r Response) Metadata() map[string]interface{} {
 	return map[string]interface{}{
-		"author":      "GenZmeY",
-		"license":     "wtfpl",
-		"license-url": "http://www.wtfpl.net",
+		"author": "GenZmeY",
 	}
 }