fix label acquired with cadvisor (#501)

inputs/cadvisor/cadvisor.go

@@ -35,3 +35,9 @@ func (c *Cadvisor) GetInstances() []inputs.Instance {
 	}
 	return ret
 }
+
+func (c *Cadvisor) Drop() {
+	for i := 0; i < len(c.Instances); i++ {
+		c.Instances[i].Drop()
+	}
+}

inputs/cadvisor/instances.go

@@ -2,6 +2,7 @@ package cadvisor
 
 import (
 	"encoding/json"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"log"
@@ -61,7 +62,7 @@ type (
 		tls.ClientConfig
 		client *http.Client
 
-		cache.BasicCache
+		*cache.BasicCache
 		stop chan struct{}
 	}
 )
@@ -78,28 +79,27 @@ func (ins *Instance) Init() error {
 	if ins.Empty() {
 		return types.ErrInstancesEmpty
 	}
-	ins.Type = ContainerType
 
 	ins.URL = strings.Replace(ins.URL, "$hostname", config.Config.GetHostname(), -1)
 	ins.URL = strings.Replace(ins.URL, "$ip", config.Config.Global.IP, -1)
 	ins.URL = os.Expand(ins.URL, config.GetEnv)
-
 	u, err := url.Parse(ins.URL)
 	if err != nil {
-		log.Println("E! failed to scrape url:", ins.URL, "error:", err)
+		return fmt.Errorf("failed to parse scrape url: %s, error: %s", ins.URL, err)
 	}
 	ins.u = u
 	if ins.u.Path == "" {
 		ins.u.Path = cadvisorPath
 		ins.Type = NodeType
 	}
 
+	ins.stop = make(chan struct{})
+	ins.BasicCache = cache.NewBasicCache()
 	go ins.cache()
 
 	if ins.Timeout <= 0 {
 		ins.Timeout = config.Duration(time.Second * 3)
 	}
-
 	client, err := ins.createHTTPClient()
 	if err != nil {
 		return err
@@ -158,31 +158,35 @@ func (ins *Instance) cache() {
 				log.Println("E! failed to request for url:", podUrl.String(), "error:", err)
 				continue
 			}
-			resp.Body.Close()
 			body, err := ioutil.ReadAll(resp.Body)
 			if err != nil {
 				log.Println("E! failed to read body for url:", podUrl.String(), "error:", err)
 				continue
 			}
+			resp.Body.Close()
 			pods := kubernetes.PodList{}
 			err = json.Unmarshal(body, &pods)
 			if err != nil {
 				log.Println("E! unmarshal pods info", err)
 				continue
 			}
 			for _, pod := range pods.Items {
-				ins.BasicCache.Add(pod.Metadata.Namespace+"||"+pod.Metadata.Name, &pod)
+				ins.BasicCache.Add(cacheKey(pod.Metadata.Namespace, pod.Metadata.Name), pod)
 			}
-			timer.Reset(10 * time.Minute)
-		case <-ins.Done():
+			timer.Reset(1 * time.Minute)
+		case <-ins.stop:
 			return
 		}
 	}
 }
 
-func (ins *Instance) Done() chan struct{} {
+func cacheKey(ns, pod string) string {
+	return ns + "||" + pod
+}
+
+func (ins *Instance) Drop() {
 	log.Println("I! cadvisor instance stop")
-	return ins.stop
+	close(ins.stop)
 }
 
 func (ins *Instance) createHTTPClient() (*http.Client, error) {
@@ -295,7 +299,10 @@ func (ins *Instance) ignoreLabel(label string) bool {
 }
 
 func (ins *Instance) makeLabels(m *dto.Metric, defaultLabels map[string]string) map[string]string {
-	result := map[string]string{}
+	var (
+		podName, namespace string
+		result             = map[string]string{}
+	)
 
 	for _, label := range m.Label {
 		if ins.ignoreLabel(label.GetName()) {
@@ -304,10 +311,21 @@ func (ins *Instance) makeLabels(m *dto.Metric, defaultLabels map[string]string)
 		result[label.GetName()] = label.GetValue()
 
 		if ins.Type == NodeType {
-			podName := label.GetName()
-			if val, ok := ins.BasicCache.Get(podName); ok {
-				if pod, ok := val.(*kubernetes.Pod); ok {
+			if label.GetName() != "pod" && label.GetName() != "namespace" {
+				continue
+			}
+			if label.GetName() == "pod" {
+				podName = label.GetValue()
+			}
+			if label.GetName() == "namespace" {
+				namespace = label.GetValue()
+			}
+			if strings.TrimSpace(podName) == "" || strings.TrimSpace(namespace) == "" {
+				continue
+			}
 
+			if val, ok := ins.BasicCache.Get(cacheKey(namespace, podName)); ok {
+				if pod, ok := val.(*kubernetes.Pod); ok {
 					for k, v := range pod.Metadata.Labels {
 						if ins.ignoreLabel(k) {
 							continue
@@ -322,8 +340,11 @@ func (ins *Instance) makeLabels(m *dto.Metric, defaultLabels map[string]string)
 						result[k] = v
 					}
 				}
+			} else {
+				if config.Config.DebugMode {
+					log.Println(cacheKey(namespace, podName), "not in cache")
+				}
 			}
-
 		}
 	}
 
@@ -359,7 +380,3 @@ func (ins *Instance) setHeaders(req *http.Request) {
 		req.Header.Set(ins.Headers[i], ins.Headers[i+1])
 	}
 }
-
-func (ins *Instance) Drop() {
-	close(ins.stop)
-}