Option to keep or remove prefix when router triggers prefix based function (#2133)

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

crds/v1/fission.io_httptriggers.yaml

@@ -76,6 +76,9 @@ spec:
                     description: TLS is for user to specify a Secret that contains TLS key and certificate. The domain name in the key and crt must match the value of Host field.
                     type: string
                 type: object
+              keepPrefix:
+                description: When function is exposed with Prefix based path, keepPrefix decides whether to keep or trim prefix in URL while invoking function.
+                type: boolean
               method:
                 description: Use Methods instead of Method. This field is going to be deprecated in a future release HTTP method to access a function.
                 type: string

pkg/apis/core/v1/types.go

@@ -664,6 +664,11 @@ type (
 		// +optional
 		Prefix *string `json:"prefix,omitempty"`
 
+		// When function is exposed with Prefix based path,
+		// keepPrefix decides whether to keep or trim prefix in URL while invoking function.
+		// +optional
+		KeepPrefix bool `json:"keepPrefix,omitempty"`
+
 		// Use Methods instead of Method. This field is going to be deprecated in a future release
 		// HTTP method to access a function.
 		// +optional

pkg/apis/core/v1/zz_generated.swagger_doc_generated.go

@@ -236,6 +236,7 @@ var map_HTTPTriggerSpec = map[string]string{
 	"host":          "Deprecated: the original idea of this field is not for setting Ingress. Since we have IngressConfig now, remove Host after couple releases.",
 	"relativeurl":   "RelativeURL is the exposed URL for external client to access a function with.",
 	"prefix":        "Prefix with which functions are exposed. NOTE: Prefix takes precedence over URL/RelativeURL. Note that it does not treat slashes specially (\"/foobar/\" will be matched by the prefix \"/foobar\").",
+	"keepPrefix":    "When function is exposed with Prefix based path, keepPrefix decides whether to keep or trim prefix in URL while invoking function.",
 	"method":        "Use Methods instead of Method. This field is going to be deprecated in a future release HTTP method to access a function.",
 	"methods":       "HTTP methods to access a function",
 	"functionref":   "FunctionReference is a reference to the target function.",

pkg/fission-cli/cmd/httptrigger/command.go

@@ -33,7 +33,8 @@ func Commands() *cobra.Command {
 		Required: []flag.Flag{flag.HtFnName},
 		Optional: []flag.Flag{flag.HtUrl, flag.HtName, flag.HtMethod, flag.HtIngress,
 			flag.HtIngressRule, flag.HtIngressAnnotation, flag.HtIngressTLS,
-			flag.HtFnWeight, flag.HtHost, flag.NamespaceFunction, flag.SpecSave, flag.SpecDry, flag.HtPrefix},
+			flag.HtFnWeight, flag.HtHost, flag.NamespaceFunction, flag.SpecSave, flag.SpecDry,
+			flag.HtPrefix, flag.HtKeepPrefix},
 	})
 
 	getCmd := &cobra.Command{
@@ -56,7 +57,8 @@ func Commands() *cobra.Command {
 		Required: []flag.Flag{flag.HtName},
 		Optional: []flag.Flag{flag.HtUrl, flag.HtFnName,
 			flag.HtMethod, flag.HtIngress, flag.HtIngressRule, flag.HtIngressAnnotation,
-			flag.HtIngressTLS, flag.HtFnWeight, flag.HtHost, flag.NamespaceTrigger, flag.HtPrefix},
+			flag.HtIngressTLS, flag.HtFnWeight, flag.HtHost, flag.NamespaceTrigger,
+			flag.HtPrefix, flag.HtKeepPrefix},
 	})
 
 	deleteCmd := &cobra.Command{

pkg/fission-cli/cmd/httptrigger/create.go

@@ -179,9 +179,14 @@ func (opts *CreateSubCommand) complete(input cli.Input) error {
 			CreateIngress:     createIngress,
 			IngressConfig:     *ingressConfig,
 			Prefix:            &prefix,
+			KeepPrefix:        input.Bool(flagkey.HtKeepPrefix),
 		},
 	}
 
+	if input.IsSet(flagkey.HtKeepPrefix) {
+		opts.trigger.Spec.KeepPrefix = input.Bool(flagkey.HtKeepPrefix)
+	}
+
 	return nil
 }
 

pkg/fission-cli/cmd/httptrigger/update.go

@@ -80,6 +80,10 @@ func (opts *UpdateSubCommand) complete(input cli.Input) error {
 	ht.Spec.RelativeURL = triggerUrl
 	ht.Spec.Prefix = &prefix
 
+	if input.IsSet(flagkey.HtKeepPrefix) {
+		ht.Spec.KeepPrefix = input.Bool(flagkey.HtKeepPrefix)
+	}
+
 	methods := input.StringSlice(flagkey.HtMethod)
 	if len(methods) > 0 {
 		for _, method := range methods {

pkg/fission-cli/flag/flag.go

@@ -134,6 +134,7 @@ var (
 	HtFnWeight          = Flag{Type: IntSlice, Name: flagkey.HtFnWeight, Usage: "Weight for each function supplied with --function flag, in the same order. Used for canary deployment"}
 	HtFnFilter          = Flag{Type: String, Name: flagkey.HtFilter, Usage: "Name of the function for trigger(s)"}
 	HtPrefix            = Flag{Type: String, Name: flagkey.HtPrefix, Usage: "Prefix with which functions are exposed. NOTE: Prefix takes precedence over URL/RelativeURL"}
+	HtKeepPrefix        = Flag{Type: Bool, Name: flagkey.HtKeepPrefix, Usage: "Keep the prefix in the URL while forwarding request to the function"}
 
 	TtName   = Flag{Type: String, Name: flagkey.TtName, Usage: "Time Trigger name"}
 	TtCron   = Flag{Type: String, Name: flagkey.TtCron, Usage: "Time trigger cron spec with each asterisk representing respectively second, minute, hour, the day of the month, month and day of the week. Also supports readable formats like '@every 5m', '@hourly'"}

pkg/fission-cli/flag/key/key.go

@@ -87,6 +87,7 @@ const (
 	HtFnWeight          = "weight"
 	HtFilter            = HtFnName
 	HtPrefix            = "prefix"
+	HtKeepPrefix        = "keepprefix"
 
 	TtName   = resourceName
 	TtCron   = "cron"

pkg/router/functionHandler.go

@@ -266,13 +266,17 @@ func (roundTripper *RetryingRoundTripper) RoundTrip(req *http.Request) (*http.Re
 			// req.URL.Path according to httpTrigger specification.
 			prefixTrim := ""
 			functionURL := utils.UrlForFunction(fnMeta.Name, fnMeta.Namespace)
+			keepPrefix := false
 			if roundTripper.funcHandler.httpTrigger != nil && roundTripper.funcHandler.httpTrigger.Spec.Prefix != nil && *roundTripper.funcHandler.httpTrigger.Spec.Prefix != "" {
 				prefixTrim = *roundTripper.funcHandler.httpTrigger.Spec.Prefix
+				keepPrefix = roundTripper.funcHandler.httpTrigger.Spec.KeepPrefix
 			} else if strings.HasPrefix(req.URL.Path, functionURL) {
 				prefixTrim = functionURL
 			}
 			if prefixTrim != "" {
-				req.URL.Path = strings.TrimPrefix(req.URL.Path, prefixTrim)
+				if !keepPrefix {
+					req.URL.Path = strings.TrimPrefix(req.URL.Path, prefixTrim)
+				}
 				if !strings.HasPrefix(req.URL.Path, "/") {
 					req.URL.Path = "/" + req.URL.Path
 				}
@@ -280,6 +284,10 @@ func (roundTripper *RetryingRoundTripper) RoundTrip(req *http.Request) (*http.Re
 				req.URL.Path = "/"
 			}
 
+			logger.Debug("function invoke url",
+				zap.String("prefixTrim", prefixTrim),
+				zap.Bool("keepPrefix", keepPrefix),
+				zap.String("hitURL", req.URL.Path))
 			// Overwrite request host with internal host,
 			// or request will be blocked in some situations
 			// (e.g. istio-proxy)