Refactor controller metrics interface

internal/ingress/metric/collectors/process_test.go

@@ -0,0 +1,93 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package collectors
+
+import (
+	"os/exec"
+	"syscall"
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func TestProcessCollector(t *testing.T) {
+	cases := []struct {
+		name    string
+		metrics []string
+	}{
+		{
+			name:    "should return metrics",
+			metrics: []string{"nginx_ingress_controller_nginx_process_num_procs"},
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			name = "sleep"
+			binary = "/bin/sleep"
+
+			cmd := exec.Command(binary, "1000000")
+			err := cmd.Start()
+			if err != nil {
+				t.Errorf("unexpected error creating dummy process: %v", err)
+			}
+
+			done := make(chan struct{})
+			go func() {
+				cmd.Wait()
+				status := cmd.ProcessState.Sys().(syscall.WaitStatus)
+				if status.Signaled() {
+					t.Logf("Signal: %v", status.Signal())
+				} else {
+					t.Logf("Status: %v", status.ExitStatus())
+				}
+			}()
+
+			cm, err := NewNGINXProcess("pod", "default", "nginx")
+			if err != nil {
+				t.Errorf("unexpected error creating nginx status collector: %v", err)
+			}
+
+			go cm.Start()
+
+			defer func() {
+				cm.Stop()
+
+				cmd.Process.Kill()
+				close(done)
+			}()
+
+			reg := prometheus.NewPedanticRegistry()
+			if err := reg.Register(cm); err != nil {
+				t.Errorf("registering collector failed: %s", err)
+			}
+
+			metrics, err := reg.Gather()
+			if err != nil {
+				t.Errorf("gathering metrics failed: %s", err)
+			}
+
+			m := filterMetrics(metrics, c.metrics)
+
+			if *m[0].GetMetric()[0].Gauge.Value < 0 {
+				t.Errorf("number of process should be > 0")
+			}
+
+			reg.Unregister(cm)
+		})
+	}
+}