add scraping for Prometheus endpoint in Kubernetes #3901
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,116 @@ | ||
| package prometheus | ||
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| import ( | ||
| "fmt" | ||
| "log" | ||
| "strings" | ||
| "time" | ||
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| "k8s.io/client-go/kubernetes" | ||
| "k8s.io/client-go/tools/cache" | ||
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| "k8s.io/api/core/v1" | ||
| "k8s.io/apimachinery/pkg/fields" | ||
| "k8s.io/apimachinery/pkg/util/wait" | ||
| "k8s.io/client-go/rest" | ||
| ) | ||
|
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| func start(p *Prometheus) error { | ||
| config, err := rest.InClusterConfig() | ||
| if err != nil { | ||
| return err | ||
| } | ||
| clientset, err := kubernetes.NewForConfig(config) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| watchlist := cache.NewListWatchFromClient(clientset.CoreV1().RESTClient(), "pods", v1.NamespaceAll, fields.Everything()) | ||
| _, controller := cache.NewInformer( | ||
| watchlist, | ||
| &v1.Pod{}, | ||
| time.Second*0, | ||
| cache.ResourceEventHandlerFuncs{ | ||
| AddFunc: func(obj interface{}) { | ||
| pod := obj.(*v1.Pod) | ||
| registerPod(pod, p) | ||
| }, | ||
| DeleteFunc: func(obj interface{}) { | ||
| pod := obj.(*v1.Pod) | ||
| unregisterPod(pod, p) | ||
| }, | ||
| UpdateFunc: func(oldObj, newObj interface{}) { | ||
| podPod := oldObj.(*v1.Pod) | ||
| newPod := newObj.(*v1.Pod) | ||
| unregisterPod(podPod, p) | ||
| registerPod(newPod, p) | ||
| }, | ||
| }, | ||
| ) | ||
|
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| go controller.Run(wait.NeverStop) | ||
| return nil | ||
| } | ||
|
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| func registerPod(pod *v1.Pod, p *Prometheus) { | ||
| url := scrapeURL(pod) | ||
| if url != nil { | ||
| log.Printf("Will scrape metrics from %v\n", *url) | ||
| p.lock.Lock() | ||
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| // add annotation as metrics tags | ||
| tags := pod.GetAnnotations() | ||
| tags["pod_name"] = pod.Name | ||
| tags["namespace"] = pod.Namespace | ||
| // add labels as metrics tags | ||
| for k, v := range pod.GetLabels() { | ||
| tags[k] = v | ||
| } | ||
| p.KubernetesPods = append(p.KubernetesPods, Target{url: *url, tags: tags}) | ||
| p.lock.Unlock() | ||
| } | ||
| } | ||
|
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| func scrapeURL(pod *v1.Pod) *string { | ||
| scrape := pod.ObjectMeta.Annotations["prometheus.io/scrape"] | ||
| if pod.Status.PodIP == "" { | ||
| // return as if scrape was disabled, we will be notified again once the pod | ||
| // has an IP | ||
| return nil | ||
| } | ||
| if scrape == "true" { | ||
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| path := pod.ObjectMeta.Annotations["prometheus.io/path"] | ||
| port := pod.ObjectMeta.Annotations["prometheus.io/port"] | ||
| if port == "" { | ||
| port = "9102" // default | ||
| } | ||
| if path == "" { | ||
| path = "/metrics" | ||
| } | ||
| if !strings.HasPrefix(path, "/") { | ||
| path = "/" + path | ||
| } | ||
|
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| ip := pod.Status.PodIP | ||
| x := fmt.Sprintf("http://%v:%v%v", ip, port, path) | ||
|
There was a problem hiding this comment. Consider using url.URL to create the url, which would avoid the need to fixup the path above and potentially handle other cases. There was a problem hiding this comment. Always using http seems like a potential issue to me. What if the service is using https? |
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| return &x | ||
| } | ||
| return nil | ||
| } | ||
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| func unregisterPod(pod *v1.Pod, p *Prometheus) { | ||
| url := scrapeURL(pod) | ||
| if url != nil { | ||
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| p.lock.Lock() | ||
| defer p.lock.Unlock() | ||
| log.Printf("Registred a delete request for %v in namespace '%v'\n", pod.Name, pod.Namespace) | ||
| var result []Target | ||
| for _, v := range p.KubernetesPods { | ||
|
There was a problem hiding this comment. I think we should use a |
||
| if v.url != *url { | ||
| result = append(result, v) | ||
| } else { | ||
| log.Printf("Will stop scraping for %v\n", *url) | ||
| } | ||
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| } | ||
| p.KubernetesPods = result | ||
| } | ||
| } | ||
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,83 @@ | ||
| package prometheus | ||
|
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| import ( | ||
| "sync" | ||
| "testing" | ||
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| "github.com/stretchr/testify/assert" | ||
| "k8s.io/api/core/v1" | ||
| metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" | ||
| ) | ||
|
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| func TestScrapeURLNoAnnotations(t *testing.T) { | ||
| p := &v1.Pod{} | ||
| p.Annotations = map[string]string{} | ||
| url := scrapeURL(p) | ||
| assert.Nil(t, url) | ||
| } | ||
| func TestScrapeURLAnnotationsNoScrape(t *testing.T) { | ||
| p := &v1.Pod{} | ||
| p.Name = "myPod" | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "false"} | ||
| url := scrapeURL(p) | ||
| assert.Nil(t, url) | ||
| } | ||
| func TestScrapeURLAnnotations(t *testing.T) { | ||
| p := pod() | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "true"} | ||
| url := scrapeURL(p) | ||
| assert.Equal(t, "http://127.0.0.1:9102/metrics", *url) | ||
| } | ||
| func TestScrapeURLAnnotationsCustomPort(t *testing.T) { | ||
| p := pod() | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "true", "prometheus.io/port": "9000"} | ||
| url := scrapeURL(p) | ||
| assert.Equal(t, "http://127.0.0.1:9000/metrics", *url) | ||
| } | ||
| func TestScrapeURLAnnotationsCustomPath(t *testing.T) { | ||
| p := pod() | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "true", "prometheus.io/path": "mymetrics"} | ||
| url := scrapeURL(p) | ||
| assert.Equal(t, "http://127.0.0.1:9102/mymetrics", *url) | ||
| } | ||
|
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| func TestScrapeURLAnnotationsCustomPathWithSep(t *testing.T) { | ||
| p := pod() | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "true", "prometheus.io/path": "/mymetrics"} | ||
| url := scrapeURL(p) | ||
| assert.Equal(t, "http://127.0.0.1:9102/mymetrics", *url) | ||
| } | ||
|
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| func TestAddPod(t *testing.T) { | ||
| prom := &Prometheus{lock: &sync.Mutex{}} | ||
| p := pod() | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "true"} | ||
| registerPod(p, prom) | ||
| assert.Equal(t, 1, len(prom.KubernetesPods)) | ||
| } | ||
| func TestAddMultiplePods(t *testing.T) { | ||
| prom := &Prometheus{lock: &sync.Mutex{}} | ||
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| p := pod() | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "true"} | ||
| registerPod(p, prom) | ||
| p.Name = "Pod2" | ||
| registerPod(p, prom) | ||
| assert.Equal(t, 2, len(prom.KubernetesPods)) | ||
| } | ||
| func TestDeletePods(t *testing.T) { | ||
| prom := &Prometheus{lock: &sync.Mutex{}} | ||
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| p := pod() | ||
| p.Annotations = map[string]string{"prometheus.io/scrape": "true"} | ||
| registerPod(p, prom) | ||
| unregisterPod(p, prom) | ||
| assert.Equal(t, 0, len(prom.KubernetesPods)) | ||
| } | ||
|
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| func pod() *v1.Pod { | ||
| p := &v1.Pod{ObjectMeta: metav1.ObjectMeta{Namespace: "default"}} | ||
| p.Status.PodIP = "127.0.0.1" | ||
| p.Name = "myPod" | ||
| return p | ||
| } |
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For these log at debug level: "
D! [inputs.prometheus] adding %q to scrape targets"