feat(helm): Add ServiceMonitor (#695)

# Description

Adding support for `ServiceMonitor`.

## Checklist

- [x] I have read the [contributing
documentation](https://retina.sh/docs/contributing).
- [x] I have tested the changes locally.
- [x] I have followed the project's style guidelines.
- [x] I have updated the documentation, if necessary.

## Screenshots (if applicable) or Testing Completed

![image
(2)](https://github.com/user-attachments/assets/f377b3b0-c41f-48ce-8e1f-0eef562ecd73)

![image
(1)](https://github.com/user-attachments/assets/c11a6aa0-e897-43a3-b29c-2c2625554fb0)

deploy/legacy/manifests/controller/helm/retina/templates/podmonitor.yaml

@@ -1,4 +1,4 @@
-{{- if .Values.metrics.podMonitor.enabled }}
+{{- if and (not .Values.metrics.serviceMonitor.enabled) .Values.metrics.podMonitor.enabled }}
 apiVersion: monitoring.coreos.com/v1
 kind: PodMonitor
 metadata:

deploy/legacy/manifests/controller/helm/retina/templates/servicemonitor.yaml

@@ -0,0 +1,45 @@
+{{- if and (not .Values.metrics.podMonitor.enabled) .Values.metrics.serviceMonitor.enabled }}
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: {{ include "retina.fullname" . }}
+  namespace: {{ ternary .Values.metrics.serviceMonitor.namespace .Values.namespace (not (empty .Values.metrics.serviceMonitor.namespace)) }}
+  labels:
+    k8s-app: {{ include "retina.name" . }}
+    {{- include "retina.labels" . | nindent 4 }}
+    app.kubernetes.io/component: metrics
+    {{- if .Values.metrics.serviceMonitor.additionalLabels }}
+    {{- toYaml .Values.metrics.serviceMonitor.additionalLabels | nindent 4 }}
+    {{- end }}
+spec:
+  endpoints:
+    - targetPort: retina
+      path: /metrics
+      {{- if .Values.metrics.serviceMonitor.interval }}
+      interval: {{ .Values.metrics.serviceMonitor.interval }}
+      {{- end }}
+      {{- if .Values.metrics.serviceMonitor.scrapeTimeout }}
+      scrapeTimeout: {{ .Values.metrics.serviceMonitor.scrapeTimeout }}
+      {{- end }}
+      {{- if .Values.metrics.serviceMonitor.scheme }}
+      scheme: {{ .Values.metrics.serviceMonitor.scheme }}
+      {{- end }}
+      {{- if .Values.metrics.serviceMonitor.tlsConfig }}
+      tlsConfig: {{- .Values.metrics.serviceMonitor.tlsConfig | nindent 8 }}
+      {{- end }}
+      {{- if .Values.metrics.serviceMonitor.relabelings }}
+      relabelings: 
+      {{- toYaml .Values.metrics.serviceMonitor.relabelings | nindent 8 }}
+      {{- end }}
+      {{- if .Values.metrics.serviceMonitor.metricRelabelings }}
+      metricRelabelings: 
+      {{- toYaml .Values.metrics.serviceMonitor.metricRelabelings | nindent 8 }}
+      {{- end }}
+  namespaceSelector:
+    matchNames:
+      - {{ .Values.namespace }}
+  selector:
+    matchLabels:
+      {{- include "retina.selectorLabels" . | nindent 6 }}
+      app.kubernetes.io/component: networking
+{{- end }}

deploy/legacy/manifests/controller/helm/retina/values.yaml

@@ -191,4 +191,38 @@ metrics:
     ## @param metrics.podMonitor.relabelings [array] Prometheus relabeling rules
     ##
     relabelings: []
-
+  serviceMonitor:
+    ## @param metrics.serviceMonitor.enabled Create serviceMonitor Resource for scraping metrics using PrometheusOperator
+    ##
+    enabled: false
+    ## @param metrics.serviceMonitor.namespace Namespace in which the serviceMonitor should be created
+    ##
+    namespace: ~
+    ## @param metrics.serviceMonitor.interval Specify the interval at which metrics should be scraped
+    ##
+    interval: 30s
+    ## @param metrics.serviceMonitor.scrapeTimeout Specify the timeout after which the scrape is ended
+    ##
+    scrapeTimeout: 30s
+    ## @param metrics.serviceMonitor.additionalLabels [object] Additional labels that can be used so serviceMonitor will be discovered by Prometheus
+    ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#prometheusspec
+    ##
+    additionalLabels: {}
+    ## @param metrics.serviceMonitor.scheme Scheme to use for scraping
+    ##
+    scheme: http
+    ## @param metrics.serviceMonitor.tlsConfig [object] TLS configuration used for scrape endpoints used by Prometheus
+    ## ref: https://github.com/prometheus-operator/prometheus-operator/blob/master/Documentation/api.md#tlsconfig
+    ## e.g:
+    ## tlsConfig:
+    ##   ca:
+    ##     secret:
+    ##       name: existingSecretName
+    ##
+    tlsConfig: {}
+    ## @param metrics.serviceMonitor.relabelings [array] Prometheus relabeling rules to apply to samples before scraping
+    ##
+    relabelings: []
+    ## @param metrics.serviceMonitor.metricRelabelings [array] Prometheus relabeling rules to apply to samples before ingestion
+    ##
+    metricRelabelings: []