Manifests for Kubernetes Prometheus

The Prometheus server monitoring Kubernetes should be default cover:
- node exporter
- kubelets
- kube-state-metrics
- apiservers

The version in this commit still has certificate issues with the API
server in minikube. Kubelet scraping likely only works in minikube as it
doesn't seem to use https.

manifests/prometheus/prometheus-k8s-cm.yaml

+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: prometheus-k8s
+data:
+  prometheus.yaml: |
+    global:
+      evaluation_interval: 30s
+
+    # Add your etcd scrape config here. We cannot default here as etcd is a
+    # prerequisite for Kubernetes.
+    # TODO(fabxc): potentially make this configurable via KPM in the future.
+
+    scrape_configs:
+    - job_name: kubelets
+      scrape_interval: 20s
+      tls_config:
+        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
+      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
+
+      kubernetes_sd_configs:
+      - role: node
+
+      relabel_configs:
+      - source_labels: [__address__]
+        regex: (.*):10250
+        replacement: ${1}:10255
+        target_label: __address__
+    
+    # Scrapes the endpoint lists for the Kubernetes API server, kube-state-metrics,
+    # and node-exporter, which we all consider part of a default setup.
+    - job_name: standard-endpoints
+      scrape_interval: 20s
+      tls_config:
+        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
+      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
+
+      kubernetes_sd_configs:
+      - role: endpoints
+
+      relabel_configs:
+      - action: keep
+        source_labels: [__meta_kubernetes_service_name]
+        regex: kubernetes|node-exporter|kube-state-metrics
+      - action: replace
+        source_labels: [__meta_kubernetes_namespace]
+        target_label: namespace
+      - action: replace
+        source_labels: [__meta_kubernetes_service_name]
+        target_label: job
+      - action: replace
+        source_labels: [__meta_kubernetes_service_name]
+        regex: kubernetes
+        target_label: __scheme__
+        replacement: https

manifests/prometheus/prometheus-k8s-svc.yaml

+apiVersion: v1
+kind: Service
+metadata:
+  name: prometheus-k8s
+spec:
+  type: NodePort
+  ports:
+  - name: web
+    nodePort: 30900
+    port: 9090
+    protocol: TCP
+    targetPort: web
+  selector:
+    prometheus.coreos.com: prometheus-k8s

manifests/prometheus/prometheus-k8s.yaml

+apiVersion: prometheus.coreos.com/v1alpha1
+kind: Prometheus
+metadata:
+  name: prometheus-k8s
+  labels:
+    prometheus: k8s
+spec: {}