Fix issue in namespace parsing for metrics function

Fixes an issue where the . was being returned in the namespace
by adding a unit test to verify the behaviour.

Tested e2e with local openfaas-cloud.

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

metrics/go.sum

@@ -0,0 +1,18 @@
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973 h1:xJ4a3vCFaGF/jqvzLMYoU8P317H5OQ+Via4RmuPwCS0=
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
+github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/openfaas/faas v0.0.0-20191227175319-80b6976c1063 h1:9dxY2GyAGl6j3+g4RN0gHsDIk3dEHuKmqlB2mkGlJ7c=
+github.com/openfaas/faas v0.0.0-20191227175319-80b6976c1063/go.mod h1:E0m2rLup0Vvxg53BKxGgaYAGcZa3Xl+vvL7vSi5yQ14=
+github.com/openfaas/faas-provider v0.0.0-20191011092439-98c25c3919da h1:IgAWwOVcLrPNc495areghkleecv3JjciOkEHpavm7go=
+github.com/openfaas/faas-provider v0.0.0-20191011092439-98c25c3919da/go.mod h1:W4OIp33RUOpR7wW+omJB/7GhIydRmYXvKf/VqUKI4yM=
+github.com/prometheus/client_golang v0.8.0 h1:1921Yw9Gc3iSc4VQh3PIoOqgPCZS7G/4xQNVUp8Mda8=
+github.com/prometheus/client_golang v0.8.0/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/common v0.0.0-20180801064454-c7de2306084e h1:n/3MEhJQjQxrOUCzh1Y3Re6aJUUWRp2M9+Oc3eVn/54=
+github.com/prometheus/common v0.0.0-20180801064454-c7de2306084e/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/procfs v0.0.0-20180725123919-05ee40e3a273 h1:agujYaXJSxSo18YNX3jzl+4G6Bstwt+kqv47GS12uL0=
+github.com/prometheus/procfs v0.0.0-20180725123919-05ee40e3a273/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=

metrics/handler.go

@@ -24,6 +24,7 @@ func Handle(req []byte) string {
 	if err != nil {
 		log.Fatalf("couldn't parse function name from query: %t", err)
 	}
+
 	if ns == "" {
 		// TODO: read from env-var for environments where this is overridden
 		ns = "openfaas-fn"
@@ -39,6 +40,7 @@ func Handle(req []byte) string {
 	metricsQuery := metrics.NewPrometheusQuery(host, port, http.DefaultClient)
 	metricsWindow := parseMetricsWindow()
 	key := fnName + "." + ns
+	// log.Printf("key: %q", key)
 	fnMetrics, err := getMetrics(key, metricsQuery, metricsWindow)
 	if err != nil {
 		log.Fatalf("Couldn't get metrics from Prometheus for function %s, %t", key, err)
@@ -72,7 +74,11 @@ func parseMetricsWindow() string {
 	return metricsWindow
 }
 
-func parseFunctionName() (name, namespace string, error error) {
+func parseFunctionName() (string, string, error) {
+	var (
+		name, namespace string
+	)
+
 	if query, exists := os.LookupEnv("Http_Query"); exists {
 		val, err := url.ParseQuery(query)
 		if err != nil {
@@ -83,7 +89,7 @@ func parseFunctionName() (name, namespace string, error error) {
 			name = functionName
 			if index := strings.Index(functionName, "."); index > -1 {
 				name = functionName[:index]
-				namespace = functionName[index:]
+				namespace = functionName[index+1:]
 			}
 
 			return name, namespace, nil
@@ -101,6 +107,7 @@ func getMetrics(fnName string, metricsQuery metrics.PrometheusQueryFetcher, metr
 		fnName,
 		metricsWindow,
 	)
+
 	expr := url.QueryEscape(queryValue)
 
 	response, err := metricsQuery.Fetch(expr)

metrics/handler_test.go

@@ -9,6 +9,38 @@ import (
 	"github.com/openfaas/faas/gateway/metrics"
 )
 
+func Test_parseFunctionName_NoSuffix(t *testing.T) {
+	os.Setenv("Http_Query", "function=alexellis-hooks&metrics_window=60m&user=alexellis")
+	n, ns, err := parseFunctionName()
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != "alexellis-hooks" {
+		t.Fatalf("want %s, got %s", "alexellis-hooks", n)
+	}
+
+	if ns != "" {
+		t.Fatalf("want %s, got %s", "", ns)
+	}
+}
+
+func Test_parseFunctionName_WithSuffix(t *testing.T) {
+	os.Setenv("Http_Query", "function=alexellis-hooks.dev&metrics_window=60m&user=alexellis")
+	n, ns, err := parseFunctionName()
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != "alexellis-hooks" {
+		t.Fatalf("want %s, got %s", "alexellis-hooks", n)
+	}
+
+	if ns != "dev" {
+		t.Fatalf("want %s, got %s", "dev", ns)
+	}
+}
+
 type FakePrometheusQueryFetcher struct {
 }