feat: Provide capability to scrape Prometheus metrics in Promitor Res…

…ource Discovery (promitor#60)

promitor-agent-resource-discovery/README.md

@@ -70,6 +70,13 @@ their default values.
 | `azureAuthentication.identity.id`  | Id of the Azure AD entity to authenticate with |             |
 | `azureAuthentication.identity.key`  | Secret of the Azure AD entity to authenticate with, when using mode `ServicePrincipal` (default) or `UserAssignedManagedIdentity` |             |
 | `azureAuthentication.identity.binding`  | Aad Pod Identity name, when using `UserAssignedManagedIdentity` or `SystemAssignedManagedIdentity` as mode |             |
+| `prometheus.enabled`  | Indication whether or not metrics should be exposed as a Prometheus scraping endpoint | `true`|
+| `prometheus.enableServiceDiscovery`  | Indication whether or not service discovery with annotations should be enabled ([docs](https://github.com/helm/charts/tree/master/stable/prometheus#scraping-pod-metrics-via-annotations)) | `true`            |
+| `prometheus.serviceMonitor.enabled`  | Indication whether or not to create a ServiceMonitor object for [Prometheus Operator](https://github.com/prometheus-operator/prometheus-operator#customresourcedefinitions) | `false`            |
+| `prometheus.serviceMonitor.namespace`  | The namespace where the ServiceMonitor should be created |                  |
+| `prometheus.serviceMonitor.labels`  | Labels for the ServiceMonitor |       `{}`           |
+| `prometheus.serviceMonitor.interval`  | How often Prometheus should scrape  | `60s`            |
+| `prometheus.serviceMonitor.timeout`  | Timeout for the scraping operation | `10s`            |
 | `cache.enabled`  | Indication whether or not discovered resources should be cached in-memory to avoid Azure throttling | `true`            |
 | `cache.durationInMinutes`  | Amount of minutes to cache discovered resources | `5`            |
 | `telemetry.applicationInsights.enabled`  | Indication whether or not to send telemetry to Azure Application Insights | `false`            |

promitor-agent-resource-discovery/templates/service.yaml

@@ -5,16 +5,21 @@ metadata:
   namespace: {{ .Release.Namespace }}
   labels:
     {{- include "promitor-agent-resource-discovery.labels" . | nindent 4 }}
-{{- if .Values.service.loadBalancer.enabled }}
-{{- if or (.Values.service.loadBalancer.azure.dnsPrefix) (.Values.service.loadBalancer.azure.exposeInternally) }}
+{{- if or (.Values.service.loadBalancer.enabled) (.Values.prometheus.enableServiceDiscovery) }}
   annotations:
+{{- if or (.Values.service.loadBalancer.azure.dnsPrefix) (.Values.service.loadBalancer.azure.exposeInternally) }}
   {{- if .Values.service.loadBalancer.azure.dnsPrefix }}
     service.beta.kubernetes.io/azure-dns-label-name: {{ .Values.service.loadBalancer.azure.dnsPrefix }}
   {{- end }}
   {{- if .Values.service.loadBalancer.azure.exposeInternally }}
     service.beta.kubernetes.io/azure-load-balancer-internal: "true"
   {{- end }}
 {{- end }}
+  {{- if .Values.prometheus.enableServiceDiscovery }}
+    prometheus.io/scrape: "true"
+    prometheus.io/path: /metrics
+    prometheus.io/port: {{ .Values.service.targetPort | quote }}
+  {{- end }}
 {{- end }}
 spec:
 {{- if .Values.service.loadBalancer.enabled }}

promitor-agent-resource-discovery/templates/servicemonitor.yaml

@@ -0,0 +1,30 @@
+{{- if and ( .Values.prometheus.serviceMonitor.enabled ) (.Values.prometheus.enabled ) }}
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  labels:
+{{- include "promitor-agent-resource-discovery.labels" . | nindent 4 }}
+{{- if .Values.prometheus.serviceMonitor.labels }}
+{{ toYaml .Values.prometheus.serviceMonitor.labels | indent 4 }}
+{{- end }}
+  name: {{ template "promitor-agent-resource-discovery.fullname" . }}
+{{- if .Values.prometheus.serviceMonitor.namespace }}
+  namespace: {{ .Values.prometheus.serviceMonitor.namespace }}
+{{- end }}
+spec:
+  endpoints:
+  - targetPort: http
+{{- if .Values.prometheus.serviceMonitor.interval }}
+    interval: {{ .Values.prometheus.serviceMonitor.interval }}
+{{- end }}
+{{- if .Values.prometheus.serviceMonitor.timeout }}
+    scrapeTimeout: {{ .Values.prometheus.serviceMonitor.timeout }}
+{{- end }}
+  jobLabel: {{ template "promitor-agent-resource-discovery.fullname" . }}
+  namespaceSelector:
+    matchNames:
+    - {{ .Release.Namespace }}
+  selector:
+    matchLabels:
+      {{- include "promitor-agent-resource-discovery.selectorLabels" . | nindent 6 }}
+{{- end }}

promitor-agent-resource-discovery/values.yaml

@@ -19,10 +19,21 @@ azureAuthentication:
     id: ""
     key: ""
     binding: ""
+
 cache:
   enabled: true
   durationInMinutes: 5
 
+prometheus:
+  enabled: true
+  enableServiceDiscovery: true
+  serviceMonitor:
+    enabled: false
+    namespace: ""
+    labels: {}
+    interval: 60s
+    timeout: 10s
+
 telemetry:
   defaultLogLevel: "Error"
   applicationInsights: