Additional validation for OpenFaaS CE scaling

A few users who haven't read the docs carefully enough were
trying to use OpenFaaS Pro scaling labels with the CE edition.

This improves the developer experience by showing them the
mistake, so they can fix it instead of raising an issue and
creating noise.

The docs cover both scaling approaches clearly along with
their labels.

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

Author: alexellis

pkg/handlers/deploy.go

@@ -150,10 +150,10 @@ func makeDeploymentSpec(request types.FunctionDeployment, existingSecrets map[st
 
 	nodeSelector := createSelector(request.Constraints)
 
-	resources, resourceErr := createResources(request)
+	resources, err := createResources(request)
 
-	if resourceErr != nil {
-		return nil, resourceErr
+	if err != nil {
+		return nil, err
 	}
 
 	var imagePullPolicy apiv1.PullPolicy

pkg/handlers/validate.go

@@ -7,12 +7,14 @@ package handlers
 import (
 	"fmt"
 	"regexp"
+	"strconv"
 
 	types "github.com/openfaas/faas-provider/types"
 )
 
 // Regex for RFC-1123 validation:
-// 	k8s.io/kubernetes/pkg/util/validation/validation.go
+//
+//	k8s.io/kubernetes/pkg/util/validation/validation.go
 var validDNS = regexp.MustCompile(`^[a-z0-9]([-a-z0-9]*[a-z0-9])?$`)
 
 // validates that the service name is valid for Kubernetes
@@ -41,5 +43,51 @@ func ValidateDeployRequest(request *types.FunctionDeployment) error {
 		return fmt.Errorf("image: is required")
 	}
 
+	if err := validateScalingLabels(request); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func validateScalingLabels(request *types.FunctionDeployment) error {
+	if request.Labels == nil {
+		return nil
+	}
+
+	labels := *request.Labels
+	if v, ok := labels["com.openfaas.scale.zero"]; ok {
+		if v == "true" {
+			return fmt.Errorf("com.openfaas.scale.zero not available for Community Edition")
+		}
+	}
+	if _, ok := labels["com.openfaas.scale.zero-duration"]; ok {
+		return fmt.Errorf("com.openfaas.scale.zero-duration not available for Community Edition")
+	}
+
+	if _, ok := labels["com.openfaas.scale.target"]; ok {
+		return fmt.Errorf("com.openfaas.scale.target not available for Community Edition")
+	}
+
+	if _, ok := labels["com.openfaas.scale.type"]; ok {
+		return fmt.Errorf("com.openfaas.scale.type not available for Community Edition")
+	}
+
+	if v, ok := labels["com.openfaas.scale.max"]; ok {
+		if vv, err := strconv.Atoi(v); err == nil {
+			if vv > MaxReplicas {
+				return fmt.Errorf("com.openfaas.scale.max is set too high for Community Edition")
+			}
+		}
+	}
+
+	if v, ok := labels["com.openfaas.scale.min"]; ok {
+		if vv, err := strconv.Atoi(v); err == nil {
+			if vv > MaxReplicas {
+				return fmt.Errorf("com.openfaas.scale.min is set too high for Community Edition")
+			}
+		}
+	}
+
 	return nil
 }

pkg/handlers/validate_test.go

@@ -0,0 +1,108 @@
+package handlers
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/openfaas/faas-provider/types"
+)
+
+func Test_validateScalingLabels(t *testing.T) {
+
+	testCases := []struct {
+		Name   string
+		Labels map[string]string
+		Err    error
+	}{
+		{
+			Name:   "empty labels",
+			Labels: map[string]string{},
+			Err:    nil,
+		},
+		{
+			Name: "com.openfaas.scale.zero",
+			Labels: map[string]string{
+				"com.openfaas.scale.zero": "true",
+			},
+			Err: fmt.Errorf("com.openfaas.scale.zero not available for Community Edition"),
+		},
+		{
+			Name: "com.openfaas.scale.zero-duration",
+			Labels: map[string]string{
+				"com.openfaas.scale.zero-duration": "15m",
+			},
+			Err: fmt.Errorf("com.openfaas.scale.zero-duration not available for Community Edition"),
+		},
+		{
+			Name: "com.openfaas.scale.target",
+			Labels: map[string]string{
+				"com.openfaas.scale.target": "10",
+			},
+			Err: fmt.Errorf("com.openfaas.scale.target not available for Community Edition"),
+		},
+		{
+			Name: "com.openfaas.scale.type",
+			Labels: map[string]string{
+				"com.openfaas.scale.type": "cpu",
+			},
+			Err: fmt.Errorf("com.openfaas.scale.type not available for Community Edition"),
+		},
+		{
+			Name: "com.openfaas.scale.min allowed",
+			Labels: map[string]string{
+				"com.openfaas.scale.min": "1",
+			},
+		},
+		{
+			Name: "com.openfaas.scale.min allowed within range",
+			Labels: map[string]string{
+				"com.openfaas.scale.min": "5",
+			},
+		},
+		{
+			Name: "com.openfaas.scale.max allowed within range",
+			Labels: map[string]string{
+				"com.openfaas.scale.max": "5",
+			},
+		},
+		{
+			Name: "com.openfaas.scale.min allowed within range",
+			Labels: map[string]string{
+				"com.openfaas.scale.min": "5",
+			},
+		},
+		{
+			Name: "com.openfaas.scale.max fails outside of range",
+			Labels: map[string]string{
+				"com.openfaas.scale.max": "6",
+			},
+			Err: fmt.Errorf("com.openfaas.scale.max is set too high for Community Edition"),
+		},
+		{
+			Name: "com.openfaas.scale.min fails outside of range",
+			Labels: map[string]string{
+				"com.openfaas.scale.min": "6",
+			},
+			Err: fmt.Errorf("com.openfaas.scale.min is set too high for Community Edition"),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			gotErr := validateScalingLabels(&types.FunctionDeployment{Labels: &tc.Labels})
+			got := fmt.Errorf("")
+			if gotErr != nil {
+				got = gotErr
+			}
+			want := fmt.Errorf("")
+			if tc.Err != nil {
+				want = tc.Err
+			}
+
+			if got.Error() != want.Error() {
+				t.Errorf("got: %v, want: %v", got, want)
+			}
+		})
+	}
+
+}