Support streaming responses from functions

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alex@openfaas.com>

gateway/vendor/github.com/openfaas/faas-provider/httputil/write_interceptor.go

@@ -7,12 +7,17 @@ import (
 )
 
 func NewHttpWriteInterceptor(w http.ResponseWriter) *HttpWriteInterceptor {
-	return &HttpWriteInterceptor{w, 0}
+	return &HttpWriteInterceptor{
+		ResponseWriter: w,
+		statusCode:     0,
+		bytesWritten:   0,
+	}
 }
 
 type HttpWriteInterceptor struct {
 	http.ResponseWriter
-	statusCode int
+	statusCode   int
+	bytesWritten int64
 }
 
 func (c *HttpWriteInterceptor) Status() int {
@@ -22,6 +27,10 @@ func (c *HttpWriteInterceptor) Status() int {
 	return c.statusCode
 }
 
+func (c *HttpWriteInterceptor) BytesWritten() int64 {
+	return c.bytesWritten
+}
+
 func (c *HttpWriteInterceptor) Header() http.Header {
 	return c.ResponseWriter.Header()
 }
@@ -30,6 +39,9 @@ func (c *HttpWriteInterceptor) Write(data []byte) (int, error) {
 	if c.statusCode == 0 {
 		c.WriteHeader(http.StatusOK)
 	}
+
+	c.bytesWritten += int64(len(data))
+
 	return c.ResponseWriter.Write(data)
 }
 

gateway/vendor/github.com/openfaas/faas-provider/types/system_events.go

@@ -0,0 +1,52 @@
+package types
+
+import "time"
+
+const (
+	TypeFunctionUsage = "function_usage"
+	TypeAPIAccess     = "api_access"
+)
+
+type Event interface {
+	EventType() string
+}
+
+type FunctionUsageEvent struct {
+	Namespace    string        `json:"namespace"`
+	FunctionName string        `json:"function_name"`
+	Started      time.Time     `json:"started"`
+	Duration     time.Duration `json:"duration"`
+	MemoryBytes  int64         `json:"memory_bytes"`
+}
+
+func (e FunctionUsageEvent) EventType() string {
+	return TypeFunctionUsage
+}
+
+type APIAccessEvent struct {
+	Actor         *Actor    `json:"actor,omitempty"`
+	Path          string    `json:"path"`
+	Method        string    `json:"method"`
+	Actions       []string  `json:"actions"`
+	ResponseCode  int       `json:"response_code"`
+	CustomMessage string    `json:"custom_message,omitempty"`
+	Namespace     string    `json:"namespace,omitempty"`
+	Time          time.Time `json:"time"`
+}
+
+func (e APIAccessEvent) EventType() string {
+	return TypeAPIAccess
+}
+
+// Actor is the user that triggered an event.
+// Get from OIDC claims, we can add any of the default OIDC profile or email claim fields if desired.
+type Actor struct {
+	// OIDC subject, a unique identifier of the user.
+	Sub string `json:"sub"`
+	// Full name of the subject, can be the name of a user of OpenFaaS component.
+	Name string `json:"name,omitempty"`
+	// OpenFaaS issuer
+	Issuer string `json:"issuer,omitempty"`
+	// Federated issuer
+	FedIssuer string `json:"fed_issuer,omitempty"`
+}