Add feature for invoking namespaced functions

When coupled with the latest version of faas-netes, the gateway
can now invoke, query and deploy functions into alternative
namespaces.

Tested e2e by creating a namespace "fn" and deploying, then
invoking a function deployed there and in the default namespace.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

gateway/handlers/baseurlresolver_test.go

@@ -5,8 +5,10 @@ package handlers
 
 import (
 	"fmt"
+	"log"
 	"net/http"
 	"net/url"
+	"strings"
 	"testing"
 )
 
@@ -27,6 +29,28 @@ func TestSingleHostBaseURLResolver(t *testing.T) {
 
 const watchdogPort = 8080
 
+func TestFunctionAsHostBaseURLResolver_WithNamespaceOverride(t *testing.T) {
+
+	suffix := "openfaas-fn.local.cluster.svc."
+	namespace := "openfaas-fn"
+	newNS := "production-fn"
+
+	r := FunctionAsHostBaseURLResolver{FunctionSuffix: suffix, FunctionNamespace: namespace}
+
+	req, _ := http.NewRequest(http.MethodGet, "http://localhost/function/hello."+newNS, nil)
+
+	resolved := r.Resolve(req)
+
+	newSuffix := strings.Replace(suffix, namespace, newNS, -1)
+
+	want := fmt.Sprintf("http://hello.%s:%d", newSuffix, watchdogPort)
+	log.Println(want)
+	if resolved != want {
+		t.Logf("r.Resolve failed, want: %s got: %s", want, resolved)
+		t.Fail()
+	}
+}
+
 func TestFunctionAsHostBaseURLResolver_WithSuffix(t *testing.T) {
 	suffix := "openfaas-fn.local.cluster.svc."
 	r := FunctionAsHostBaseURLResolver{FunctionSuffix: suffix}
@@ -35,7 +59,7 @@ func TestFunctionAsHostBaseURLResolver_WithSuffix(t *testing.T) {
 
 	resolved := r.Resolve(req)
 	want := fmt.Sprintf("http://hello.%s:%d", suffix, watchdogPort)
-
+	log.Println(want)
 	if resolved != want {
 		t.Logf("r.Resolve failed, want: %s got: %s", want, resolved)
 		t.Fail()

gateway/handlers/forwarding_proxy.go

@@ -179,7 +179,8 @@ func (s SingleHostBaseURLResolver) Resolve(r *http.Request) string {
 
 // FunctionAsHostBaseURLResolver resolves URLs using a function from the URL as a host
 type FunctionAsHostBaseURLResolver struct {
-	FunctionSuffix string
+	FunctionSuffix    string
+	FunctionNamespace string
 }
 
 // Resolve the base URL for a request
@@ -188,8 +189,13 @@ func (f FunctionAsHostBaseURLResolver) Resolve(r *http.Request) string {
 
 	const watchdogPort = 8080
 	var suffix string
+
 	if len(f.FunctionSuffix) > 0 {
-		suffix = "." + f.FunctionSuffix
+		if index := strings.LastIndex(svcName, "."); index > -1 && len(svcName) > index+1 {
+			suffix = strings.Replace(f.FunctionSuffix, f.FunctionNamespace, "", -1)
+		} else {
+			suffix = "." + f.FunctionSuffix
+		}
 	}
 
 	return fmt.Sprintf("http://%s%s:%d", svcName, suffix, watchdogPort)

gateway/handlers/forwarding_proxy_test.go

@@ -135,6 +135,11 @@ func Test_getServiceName(t *testing.T) {
 			url:         "/function/testFunc",
 			serviceName: "testFunc",
 		},
+		{
+			name:        "includes namespace",
+			url:         "/function/test1.fn",
+			serviceName: "test1.fn",
+		},
 		{
 			name:        "can handle request with trailing slash",
 			url:         "/function/testFunc/",

gateway/handlers/function_prefix_trimming_url_path_transformer_test.go

@@ -32,6 +32,30 @@ func Test_Transform_RemovesFunctionPrefixWithSingleParam(t *testing.T) {
 	}
 }
 
+func Test_Transform_RemovesFunctionPrefixWithDotInName(t *testing.T) {
+
+	req, _ := http.NewRequest(http.MethodGet, "/function/figlet.fn", nil)
+	transformer := FunctionPrefixTrimmingURLPathTransformer{}
+	want := ""
+	got := transformer.Transform(req)
+
+	if want != got {
+		t.Errorf("want: %s, got: %s", want, got)
+	}
+}
+
+func Test_Transform_RemovesFunctionPrefixWithDotInNameAndPath(t *testing.T) {
+
+	req, _ := http.NewRequest(http.MethodGet, "/function/figlet.fn/employees", nil)
+	transformer := FunctionPrefixTrimmingURLPathTransformer{}
+	want := "/employees"
+	got := transformer.Transform(req)
+
+	if want != got {
+		t.Errorf("want: %s, got: %s", want, got)
+	}
+}
+
 func Test_Transform_RemovesFunctionPrefixWithParams(t *testing.T) {
 
 	req, _ := http.NewRequest(http.MethodGet, "/function/figlet/employees/100", nil)

gateway/handlers/notifiers.go

@@ -66,7 +66,7 @@ func getServiceName(urlValue string) string {
 	forward := "/function/"
 	if strings.HasPrefix(urlValue, forward) {
 		// With a path like `/function/xyz/rest/of/path?q=a`, the service
-		// name we wish to locate is just the `xyz` portion.  With a postive
+		// name we wish to locate is just the `xyz` portion.  With a positive
 		// match on the regex below, it will return a three-element slice.
 		// The item at index `0` is the same as `urlValue`, at `1`
 		// will be the service name we need, and at `2` the rest of the path.