[loki] Make ServiceMonitor jobPrefix configurable (#192)

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

Author: jkroepke

charts/loki/Chart.yaml

@@ -3,7 +3,7 @@ name: loki
 description: Helm chart for Grafana Loki supporting monolithic, simple scalable, and microservices modes.
 type: application
 appVersion: 3.6.7
-version: 8.1.1
+version: 8.1.2
 kubeVersion: ">=1.25.0-0"
 home: https://grafana-community.github.io/helm-charts
 sources:

charts/loki/templates/monitoring/servicemonitor.yaml

@@ -38,10 +38,12 @@ spec:
       scrapeTimeout: {{ . }}
       {{- end }}
       relabelings:
+        {{- with .jobPrefix }}
         - sourceLabels: [job]
           action: replace
-          replacement: "{{ include "loki.namespace" $ }}/$1"
+          replacement: "{{ tpl . $}}$1"
           targetLabel: job
+        {{- end }}
         - action: replace
           replacement: "{{ include "loki.clusterLabel" $ }}"
           targetLabel: cluster

charts/loki/values.yaml

@@ -4364,6 +4364,9 @@ monitoring:
     scheme: http
     # -- ServiceMonitor will use these tlsConfig settings to make the health check requests
     tlsConfig: null
+    # -- ServiceMonitor job label prefix will be used to generate the job label for the scraped metrics.
+    # -- The job label is required for the included dashboards to work.
+    jobPrefix: '{{ include "loki.namespace" $ }}/'
     # -- DEPRECATED If defined, will create a MetricsInstance for the Grafana Agent Operator.
     metricsInstance:
       # -- If enabled, MetricsInstance resources for Grafana Agent Operator are created