kube-prometheus: Adapt CoreDNS default configuration to default CoreDNS installs

jsonnet/kube-prometheus/kube-prometheus.libsonnet

@@ -29,6 +29,7 @@ local configMapList = k.core.v1.configMapList;
     kubeSchedulerSelector: 'job="kube-scheduler"',
     kubeControllerManagerSelector: 'job="kube-controller-manager"',
     kubeApiserverSelector: 'job="apiserver"',
+    coreDNSSelector: 'job="kube-dns"',
     podLabel: 'pod',
 
     alertmanagerSelector: 'job="alertmanager-main"',
@@ -45,6 +46,7 @@ local configMapList = k.core.v1.configMapList;
       Alertmanager: $._config.alertmanagerSelector,
       Prometheus: $._config.prometheusSelector,
       PrometheusOperator: $._config.prometheusOperatorSelector,
+      CoreDNS: $._config.coreDNSSelector,
     },
 
     prometheus+:: {

jsonnet/kube-prometheus/prometheus/prometheus.libsonnet

@@ -386,11 +386,9 @@ local k = import 'ksonnet/ksonnet.beta.3/k.libsonnet';
           },
         },
         spec: {
-          jobLabel: 'k8s-app',
           selector: {
             matchLabels: {
-              'k8s-app': 'coredns',
-              component: 'metrics',
+              'k8s-app': 'kube-dns',
             },
           },
           namespaceSelector: {
@@ -400,7 +398,7 @@ local k = import 'ksonnet/ksonnet.beta.3/k.libsonnet';
           },
           endpoints: [
             {
-              port: 'http-metrics',
+              port: 'metrics',
               interval: '15s',
               bearerTokenFile: '/var/run/secrets/kubernetes.io/serviceaccount/token',
             },