Implement default upper bound for scaling

OpenFaaS CE is licensed for 5/5 replicas, for higher load
get in touch with us about OpenFaaS Standard.

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

Author: alexellis

pkg/handlers/delete.go

@@ -8,7 +8,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 
 	"github.com/openfaas/faas-provider/types"
@@ -42,7 +42,7 @@ func MakeDeleteHandler(defaultNamespace string, clientset *kubernetes.Clientset)
 			return
 		}
 
-		body, _ := ioutil.ReadAll(r.Body)
+		body, _ := io.ReadAll(r.Body)
 
 		request := types.DeleteFunctionRequest{}
 		err := json.Unmarshal(body, &request)

pkg/handlers/deploy.go

@@ -8,7 +8,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"sort"
@@ -40,7 +40,7 @@ func MakeDeployHandler(functionNamespace string, factory k8s.FunctionFactory) ht
 			defer r.Body.Close()
 		}
 
-		body, _ := ioutil.ReadAll(r.Body)
+		body, _ := io.ReadAll(r.Body)
 
 		request := types.FunctionDeployment{}
 		err := json.Unmarshal(body, &request)

pkg/handlers/namespaces.go

@@ -9,6 +9,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"net/http"
@@ -65,7 +66,7 @@ func NewNamespaceResolver(defaultNamespace string, kube kubernetes.Interface) Na
 			}
 
 		case http.MethodPost, http.MethodPut, http.MethodDelete:
-			body, _ := ioutil.ReadAll(r.Body)
+			body, _ := io.ReadAll(r.Body)
 			err := json.Unmarshal(body, &req)
 			if err != nil {
 				log.Printf("error while getting namespace: %s\n", err)

pkg/handlers/replica_reader.go

@@ -19,6 +19,9 @@ import (
 	glog "k8s.io/klog"
 )
 
+// MaxReplicas licensed for OpenFaaS CE is 5/5
+const MaxReplicas = 5
+
 // MakeReplicaReader reads the amount of replicas for a deployment
 func MakeReplicaReader(defaultNamespace string, lister v1.DeploymentLister) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {

pkg/handlers/replica_updater.go

@@ -8,7 +8,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 
@@ -44,7 +44,7 @@ func MakeReplicaUpdater(defaultNamespace string, clientset *kubernetes.Clientset
 
 		if r.Body != nil {
 			defer r.Body.Close()
-			bytesIn, _ := ioutil.ReadAll(r.Body)
+			bytesIn, _ := io.ReadAll(r.Body)
 			marshalErr := json.Unmarshal(bytesIn, &req)
 			if marshalErr != nil {
 				w.WriteHeader(http.StatusBadRequest)
@@ -56,7 +56,9 @@ func MakeReplicaUpdater(defaultNamespace string, clientset *kubernetes.Clientset
 		}
 
 		if req.Replicas == 0 {
-			http.Error(w, fmt.Errorf("for OpenFaaS CE, replicas cannot be set to 0").Error(), http.StatusBadRequest)
+			http.Error(w, "replicas cannot be set to 0 in OpenFaaS CE",
+				http.StatusBadRequest)
+			return
 		}
 
 		options := metav1.GetOptions{
@@ -77,17 +79,19 @@ func MakeReplicaUpdater(defaultNamespace string, clientset *kubernetes.Clientset
 
 		oldReplicas := *deployment.Spec.Replicas
 		replicas := int32(req.Replicas)
+		if replicas >= MaxReplicas {
+			replicas = MaxReplicas
+		}
 
 		log.Printf("Set replicas - %s %s, %d/%d\n", functionName, lookupNamespace, replicas, oldReplicas)
 
 		deployment.Spec.Replicas = &replicas
 
-		_, err = clientset.AppsV1().Deployments(lookupNamespace).Update(context.TODO(), deployment, metav1.UpdateOptions{})
+		if _, err = clientset.AppsV1().Deployments(lookupNamespace).
+			Update(context.TODO(), deployment, metav1.UpdateOptions{}); err != nil {
 
-		if err != nil {
-			w.WriteHeader(http.StatusInternalServerError)
-			w.Write([]byte("Unable to update function deployment " + functionName))
-			log.Println(err)
+			log.Printf("unable to update function deployment: %s, %s", functionName, err)
+			http.Error(w, fmt.Sprintf("unable to update function deployment: %s", functionName), http.StatusInternalServerError)
 			return
 		}
 

pkg/handlers/secrets_test.go

@@ -8,7 +8,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -284,7 +284,7 @@ func Test_SecretsHandler_ListEmpty(t *testing.T) {
 	if resp.StatusCode != http.StatusOK {
 		t.Errorf("want status code '%d', got '%d'", http.StatusOK, resp.StatusCode)
 	}
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 
 	if string(body) == "null" {
 		t.Errorf(`want empty list to be valid json i.e. "[]", but was %q`, string(body))

pkg/handlers/update.go

@@ -7,7 +7,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"time"
@@ -26,7 +26,7 @@ func MakeUpdateHandler(defaultNamespace string, factory k8s.FunctionFactory) htt
 			defer r.Body.Close()
 		}
 
-		body, _ := ioutil.ReadAll(r.Body)
+		body, _ := io.ReadAll(r.Body)
 
 		request := types.FunctionDeployment{}
 		err := json.Unmarshal(body, &request)