Return out of handler when detecting error

This commit updates the update/create handlers so that they exit
the function after writing a header. There was an error observed
of multiple headers being written.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Author: alexellis

handlers/deploy.go

@@ -5,6 +5,7 @@ package handlers
 
 import (
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"log"
 	"net/http"
@@ -36,13 +37,14 @@ func MakeDeployHandler(functionNamespace string, factory k8s.FunctionFactory) ht
 		request := types.FunctionDeployment{}
 		err := json.Unmarshal(body, &request)
 		if err != nil {
-			w.WriteHeader(http.StatusBadRequest)
+			wrappedErr := fmt.Errorf("failed to unmarshal request: %s", err.Error())
+			http.Error(w, wrappedErr.Error(), http.StatusBadRequest)
 			return
 		}
 
 		if err := ValidateDeployRequest(&request); err != nil {
-			w.WriteHeader(http.StatusBadRequest)
-			w.Write([]byte(err.Error()))
+			wrappedErr := fmt.Errorf("validation failed: %s", err.Error())
+			http.Error(w, wrappedErr.Error(), http.StatusBadRequest)
 			return
 		}
 
@@ -53,26 +55,27 @@ func MakeDeployHandler(functionNamespace string, factory k8s.FunctionFactory) ht
 
 		existingSecrets, err := getSecrets(factory.Client, namespace, request.Secrets)
 		if err != nil {
-			w.WriteHeader(http.StatusBadRequest)
-			w.Write([]byte(err.Error()))
+			wrappedErr := fmt.Errorf("unable to fetch secrets: %s", err.Error())
+			http.Error(w, wrappedErr.Error(), http.StatusBadRequest)
 			return
 		}
 
 		deploymentSpec, specErr := makeDeploymentSpec(request, existingSecrets, factory)
 
 		if specErr != nil {
-			w.WriteHeader(http.StatusBadRequest)
-			w.Write([]byte(specErr.Error()))
+			wrappedErr := fmt.Errorf("failed create Deployment spec: %s", specErr.Error())
+			log.Println(wrappedErr)
+			http.Error(w, wrappedErr.Error(), http.StatusBadRequest)
 			return
 		}
 
 		deploy := factory.Client.AppsV1().Deployments(namespace)
 
 		_, err = deploy.Create(deploymentSpec)
 		if err != nil {
-			log.Println(err)
-			w.WriteHeader(http.StatusInternalServerError)
-			w.Write([]byte(err.Error()))
+			wrappedErr := fmt.Errorf("unable create Deployment: %s", err.Error())
+			log.Println(wrappedErr)
+			http.Error(w, wrappedErr.Error(), http.StatusInternalServerError)
 			return
 		}
 
@@ -83,9 +86,9 @@ func MakeDeployHandler(functionNamespace string, factory k8s.FunctionFactory) ht
 		_, err = service.Create(serviceSpec)
 
 		if err != nil {
-			log.Println(err)
-			w.WriteHeader(http.StatusInternalServerError)
-			w.Write([]byte(err.Error()))
+			wrappedErr := fmt.Errorf("failed create Service: %s", err.Error())
+			log.Println(wrappedErr)
+			http.Error(w, wrappedErr.Error(), http.StatusBadRequest)
 			return
 		}
 

handlers/update.go

@@ -33,34 +33,39 @@ func MakeUpdateHandler(defaultNamespace string, factory k8s.FunctionFactory) htt
 
 		if lookupNamespace == "kube-system" {
 			http.Error(w, "unable to list within the kube-system namespace", http.StatusUnauthorized)
+			return
 		}
 
 		body, _ := ioutil.ReadAll(r.Body)
 
 		request := types.FunctionDeployment{}
 		err := json.Unmarshal(body, &request)
 		if err != nil {
-			w.WriteHeader(http.StatusBadRequest)
+			wrappedErr := fmt.Errorf("unable to unmarshal request: %s", err.Error())
+			http.Error(w, wrappedErr.Error(), http.StatusBadRequest)
 			return
 		}
 
 		annotations := buildAnnotations(request)
 		if err, status := updateDeploymentSpec(lookupNamespace, factory, request, annotations); err != nil {
 			if !isNotFound(err) {
 				log.Printf("error updating deployment: %s\n", err)
+
 				return
 			}
-			w.WriteHeader(status)
-			w.Write([]byte(err.Error()))
+
+			wrappedErr := fmt.Errorf("unable update Deployment: %s", err.Error())
+			http.Error(w, wrappedErr.Error(), status)
+			return
 		}
 
 		if err, status := updateService(lookupNamespace, factory, request, annotations); err != nil {
 			if !isNotFound(err) {
 				log.Printf("error updating service: %s\n", err)
 			}
 
-			w.WriteHeader(status)
-			w.Write([]byte(err.Error()))
+			wrappedErr := fmt.Errorf("unable update Service: %s", err.Error())
+			http.Error(w, wrappedErr.Error(), status)
 			return
 		}