chore(test): create a struct and interface to allow kube client mocks…

… in handlers

pkg/apiserver/server.go

@@ -157,7 +157,7 @@ func Start(params *APIServerParams) {
 	loggingRouter := r.NewRoute().Subrouter()
 	loggingRouter.Use(handlers.LoggingMiddleware)
 
-	handler := &handlers.Handler{}
+	handler := handlers.NewHandler()
 
 	/**********************************************************************
 	* Unauthenticated routes

pkg/handlers/handlers.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/gorilla/mux"
 	"github.com/gorilla/websocket"
+	"github.com/replicatedhq/kots/pkg/handlers/kubeclient"
 	"github.com/replicatedhq/kots/pkg/logger"
 	"github.com/replicatedhq/kots/pkg/policy"
 	"github.com/replicatedhq/kots/pkg/store"
@@ -20,6 +21,15 @@ import (
 var _ KOTSHandler = (*Handler)(nil)
 
 type Handler struct {
+	// KubeClientBuilder is used to get a kube client. It is useful to mock the client in testing scenarios.
+	kubeclient.KubeClientBuilder
+}
+
+// NewHandler returns a new default Handler
+func NewHandler() *Handler {
+	return &Handler{
+		KubeClientBuilder: &kubeclient.Builder{},
+	}
 }
 
 func init() {

pkg/handlers/kubeclient/kubeclient.go

@@ -0,0 +1,35 @@
+package kubeclient
+
+import (
+	"context"
+
+	"github.com/replicatedhq/kots/pkg/k8sutil"
+	kbclient "sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+var _ KubeClientBuilder = (*Builder)(nil)
+var _ KubeClientBuilder = (*MockBuilder)(nil)
+
+// KubeClientBuilder interface is used as an abstraction to get a kube client. Useful to mock the client in tests.
+type KubeClientBuilder interface {
+	GetKubeClient(ctx context.Context) (kbclient.Client, error)
+}
+
+// Builder is the default implementation of KubeClientBuilder. It returns a regular kube client.
+type Builder struct{}
+
+// GetKubeClient returns a regular kube client.
+func (b *Builder) GetKubeClient(ctx context.Context) (kbclient.Client, error) {
+	return k8sutil.GetKubeClient(ctx)
+}
+
+// MockBuilder is a mock implementation of KubeClientBuilder. It returns the client that was set in the struct allowing
+// you to set a fakeClient for example.
+type MockBuilder struct {
+	client kbclient.Client
+}
+
+// GetKubeClient returns the client that was set in the struct.
+func (b *MockBuilder) GetKubeClient(ctx context.Context) (kbclient.Client, error) {
+	return b.client, nil
+}