Introduce "cf_on_k8s": true into the / response

Also introduce root response presenter and response type

Issue: #10

Co-authored-by: Georgi Sabev <georgethebeatle@gmail.com>

apis/root_handler.go

@@ -1,8 +1,11 @@
 package apis
 
 import (
+	"encoding/json"
 	"net/http"
 
+	"code.cloudfoundry.org/cf-k8s-api/presenter"
+	"github.com/go-logr/logr"
 	"github.com/gorilla/mux"
 )
 
@@ -11,11 +14,17 @@ const (
 )
 
 type RootHandler struct {
+	Logger    logr.Logger
 	ServerURL string
 }
 
 func (h *RootHandler) RootGetHandler(w http.ResponseWriter, r *http.Request) {
-	body := `{"links":{"self":{"href":"` + h.ServerURL + `"},"bits_service":null,"cloud_controller_v2":null,"cloud_controller_v3":{"href":"` + h.ServerURL + `/v3","meta":{"version":"3.90.0"}},"network_policy_v0":null,"network_policy_v1":null,"login":null,"uaa":null,"credhub":null,"routing":null,"logging":null,"log_cache":null,"log_stream":null,"app_ssh":null}}`
+	body, err := json.Marshal(presenter.GetRootResponse(h.ServerURL))
+	if err != nil {
+		h.Logger.Error(err, "Failed to render response")
+		writeUnknownErrorResponse(w)
+		return
+	}
 
 	w.Header().Set("Content-Type", "application/json")
 	w.Write([]byte(body))

apis/root_handler_test.go

@@ -1,14 +1,18 @@
 package apis_test
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 
 	"github.com/gorilla/mux"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
 
 	"code.cloudfoundry.org/cf-k8s-api/apis"
+	"code.cloudfoundry.org/cf-k8s-api/presenter"
 	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gstruct"
 	"github.com/sclevine/spec"
 	"github.com/sclevine/spec/report"
 )
@@ -30,6 +34,7 @@ func testRootAPI(t *testing.T, when spec.G, it spec.S) {
 		router := mux.NewRouter()
 
 		apiHandler := apis.RootHandler{
+			Logger:    logf.Log.WithName("TestRootHandler"),
 			ServerURL: defaultServerURL,
 		}
 		apiHandler.RegisterRoutes(router)
@@ -51,7 +56,32 @@ func testRootAPI(t *testing.T, when spec.G, it spec.S) {
 	})
 
 	it("matches the expected response body format", func() {
-		expectedBody := `{"links":{"self":{"href":"` + defaultServerURL + `"},"bits_service":null,"cloud_controller_v2":null,"cloud_controller_v3":{"href":"` + defaultServerURL + `/v3","meta":{"version":"3.90.0"}},"network_policy_v0":null,"network_policy_v1":null,"login":null,"uaa":null,"credhub":null,"routing":null,"logging":null,"log_cache":null,"log_stream":null,"app_ssh":null}}`
-		g.Expect(rr.Body.String()).To(Equal(expectedBody), "Response body matches RootV3GetHandler response:")
+		var resp presenter.RootResponse
+		g.Expect(json.Unmarshal(rr.Body.Bytes(), &resp)).To(Succeed())
+
+		g.Expect(resp).To(gstruct.MatchAllFields(gstruct.Fields{
+			"Links": Equal(map[string]*presenter.APILink{
+				"self": {
+					Link: presenter.Link{HREF: defaultServerURL},
+				},
+				"bits_service":        nil,
+				"cloud_controller_v2": nil,
+				"cloud_controller_v3": {
+					Link: presenter.Link{HREF: defaultServerURL + "/v3"},
+					Meta: presenter.APILinkMeta{Version: "3.90.0"},
+				},
+				"network_policy_v0": nil,
+				"network_policy_v1": nil,
+				"login":             nil,
+				"uaa":               nil,
+				"credhub":           nil,
+				"routing":           nil,
+				"logging":           nil,
+				"log_cache":         nil,
+				"log_stream":        nil,
+				"app_ssh":           nil,
+			}),
+			"CFOnK8s": Equal(true),
+		}))
 	})
 }

main.go

@@ -53,6 +53,7 @@ func main() {
 			ServerURL: config.ServerURL,
 		},
 		&apis.RootHandler{
+			Logger:    ctrl.Log.WithName("RootHandler"),
 			ServerURL: config.ServerURL,
 		},
 		&apis.ResourceMatchesHandler{

presenter/root.go

@@ -0,0 +1,37 @@
+package presenter
+
+type APILink struct {
+	Link
+	Meta APILinkMeta `json:"meta"`
+}
+
+type APILinkMeta struct {
+	Version string `json:"version"`
+}
+
+type RootResponse struct {
+	Links   map[string]*APILink `json:"links"`
+	CFOnK8s bool                `json:"cf_on_k8s"`
+}
+
+func GetRootResponse(serverURL string) RootResponse {
+	return RootResponse{
+		Links: map[string]*APILink{
+			"self":                {Link: Link{HREF: serverURL}},
+			"bits_service":        nil,
+			"cloud_controller_v2": nil,
+			"cloud_controller_v3": {Link: Link{HREF: serverURL + "/v3"}, Meta: APILinkMeta{Version: "3.90.0"}},
+			"network_policy_v0":   nil,
+			"network_policy_v1":   nil,
+			"login":               nil,
+			"uaa":                 nil,
+			"credhub":             nil,
+			"routing":             nil,
+			"logging":             nil,
+			"log_cache":           nil,
+			"log_stream":          nil,
+			"app_ssh":             nil,
+		},
+		CFOnK8s: true,
+	}
+}