Use labels instead of separate metrics (#127)

Signed-off-by: Antony Dovgal <[email protected]>

README.md

@@ -232,21 +232,21 @@ Usage of k8s-image-availability-exporter:
 
 The following metrics for Prometheus are provided:
 
-* `k8s_image_availability_exporter_<TYPE>_available` — non-zero indicates *successful* image check.
-* `k8s_image_availability_exporter_<TYPE>_bad_image_format` — non-zero indicates incorrect `image` field format.
-* `k8s_image_availability_exporter_<TYPE>_absent` — non-zero indicates an image's manifest absence from container registry.
-* `k8s_image_availability_exporter_<TYPE>_registry_unavailable` — non-zero indicates general registry unavailiability, perhaps, due to network outage.
-* `k8s_image_availability_exporter_deployment_registry_v1_api_not_supported` — non-zero indicates v1 Docker Registry API, these images are best ignored with `--ignored-images` cmdline parameter.
-* `k8s_image_availability_exporter_<TYPE>_authentication_failure` — non-zero indicates authentication error to container registry, verify imagePullSecrets.
-* `k8s_image_availability_exporter_<TYPE>_authorization_failure` — non-zero indicates authorization error to container registry, verify imagePullSecrets.
-* `k8s_image_availability_exporter_<TYPE>_unknown_error` — non-zero indicates an error that failed to be classified, consult exporter's logs for additional information.
-
-Each `<TYPE>` in the exporter's metrics name is replaced with the following values:
-
-* `deployment`
-* `statefulset`
-* `daemonset`
-* `cronjob`
+* `k8s_image_availability_exporter_available` — non-zero indicates *successful* image check.
+* `k8s_image_availability_exporter_absent` — non-zero indicates an image's manifest absence from container registry.
+* `k8s_image_availability_exporter_bad_image_format` — non-zero indicates incorrect `image` field format.
+* `k8s_image_availability_exporter_registry_unavailable` — non-zero indicates general registry unavailiability, perhaps, due to network outage.
+* `k8s_image_availability_exporter_authentication_failure` — non-zero indicates authentication error to container registry, verify imagePullSecrets.
+* `k8s_image_availability_exporter_authorization_failure` — non-zero indicates authorization error to container registry, verify imagePullSecrets.
+* `k8s_image_availability_exporter_unknown_error` — non-zero indicates an error that failed to be classified, consult exporter's logs for additional information.
+
+Each metric has the following labels:
+
+* `namespace` - namespace name
+* `container` - container name
+* `image` - image URL in the registry
+* `kind` - Kubernetes controller kind, namely `deployment`, `statefulset`, `daemonset` or `cronjob`
+* `name` - controller name
 
 ## Compatibility
 

charts/k8s-image-availability-exporter/templates/prometheus-rule.yaml

@@ -10,52 +10,52 @@ spec:
     rules:
     - alert: DeploymentImageUnavailable
       expr: |
-        max by (namespace, deployment, container, image) (
-          k8s_image_availability_exporter_deployment_available == 0
+        max by (namespace, name, container, image) (
+          k8s_image_availability_exporter_available{kind="deployment"} == 0
         )
       annotations:
         message: >
           Image {{`{{ $labels.image }}`}} from container {{`{{ $labels.container }}`}}
-          in deployment {{`{{ $labels.deployment }}`}}
+          in deployment {{`{{ $labels.name }}`}}
           from namespace {{`{{ $labels.namespace }}`}}
           is not available in docker registry.
       labels:
         severity: critical
     - alert: StatefulSetImageUnavailable
       expr: |
-        max by (namespace, statefulset, container, image) (
-          k8s_image_availability_exporter_statefulset_available == 0
+        max by (namespace, name, container, image) (
+          k8s_image_availability_exporter_available{kind="statefulset"} == 0
         )
       annotations:
         message: >
           Image {{`{{ $labels.image }}`}} from container {{`{{ $labels.container }}`}}
-          in statefulSet {{`{{ $labels.statefulset }}`}}
+          in statefulSet {{`{{ $labels.name }}`}}
           from namespace {{`{{ $labels.namespace }}`}}
           is not available in docker registry.
       labels:
         severity: critical
     - alert: DaemonSetImageUnavailable
       expr: |
-        max by (namespace, daemonset, container, image) (
-          k8s_image_availability_exporter_daemonset_available == 0
+        max by (namespace, name, container, image) (
+          k8s_image_availability_exporter_available{kind="daemonset"} == 0
         )
       annotations:
         message: >
           Image {{`{{ $labels.image }}`}} from container {{`{{ $labels.container }}`}}
-          in daemonSet {{`{{ $labels.daemonset }}`}}
+          in daemonSet {{`{{ $labels.name }}`}}
           from namespace {{`{{ $labels.namespace }}`}}
           is not available in docker registry.
       labels:
         severity: critical
     - alert: CronJobImageUnavailable
       expr: |
-        max by (namespace, cronjob, container, image) (
-          k8s_image_availability_exporter_cronjob_available == 0
+        max by (namespace, name, container, image) (
+          k8s_image_availability_exporter_available{kind="cronjob"} == 0
         )
       annotations:
         message: >
           Image {{`{{ $labels.image }}`}} from container {{`{{ $labels.container }}`}}
-          in cronJob {{`{{ $labels.cronjob }}`}}
+          in cronJob {{`{{ $labels.name }}`}}
           from namespace {{`{{ $labels.namespace }}`}}
           is not available in docker registry.
       labels:

pkg/store/image_store.go

@@ -1,7 +1,6 @@
 package store
 
 import (
-	"fmt"
 	"strings"
 	"sync"
 	"time"
@@ -217,35 +216,22 @@ func newNamedConstMetrics(ownerKind, ownerName, namespace, container, image stri
 		"namespace": namespace,
 		"container": container,
 		"image":     image,
+		"kind":      strings.ToLower(ownerKind),
+		"name":      ownerName,
 	}
 
-	switch ownerKind {
-	case "Deployment":
-		labels["deployment"] = ownerName
-		return getMetricByControllerKind(ownerKind, labels, avalMode)
-	case "StatefulSet":
-		labels["statefulset"] = ownerName
-		return getMetricByControllerKind(ownerKind, labels, avalMode)
-	case "DaemonSet":
-		labels["daemonset"] = ownerName
-		return getMetricByControllerKind(ownerKind, labels, avalMode)
-	case "CronJob":
-		labels["cronjob"] = ownerName
-		return getMetricByControllerKind(ownerKind, labels, avalMode)
-	default:
-		panic(fmt.Sprintf("received unknown metric name: %s", ownerKind))
-	}
+	return getMetric(labels, avalMode)
 }
 
-func getMetricByControllerKind(controllerKind string, labels map[string]string, mode AvailabilityMode) (ret []prometheus.Metric) {
+func getMetric(labels map[string]string, mode AvailabilityMode) (ret []prometheus.Metric) {
 	for availMode, desc := range AvailabilityModeDescMap {
 		var value float64
 		if availMode == mode {
 			value = 1
 		}
 
 		ret = append(ret, prometheus.MustNewConstMetric(
-			prometheus.NewDesc("k8s_image_availability_exporter_"+strings.ToLower(controllerKind)+"_"+desc, "", nil, labels),
+			prometheus.NewDesc("k8s_image_availability_exporter_"+desc, "", nil, labels),
 			prometheus.GaugeValue,
 			value,
 		))