[prometheus-kafka-exporter] add support for valueFrom in env variables (

#3754)

Signed-off-by: Marc Troelitzsch <[email protected]>

charts/prometheus-kafka-exporter/Chart.yaml

@@ -3,7 +3,7 @@ appVersion: "v1.6.0"
 description: A Helm chart to export the metrics from Kafka in Prometheus format using the kafka-exporter from https://github.com/danielqsj/kafka_exporter
 name: prometheus-kafka-exporter
 home: https://github.com/danielqsj/kafka_exporter
-version: 2.3.0
+version: 2.4.0
 kubeVersion: ">=1.19.0-0"
 sources:
   - https://gkarthiks.github.io/helm-charts/charts/prometheus-kafka-exporter

charts/prometheus-kafka-exporter/templates/deployment.yaml

@@ -81,9 +81,8 @@ spec:
           {{- end }}
           {{- end }}
           env:
-          {{- range $env := .Values.env }}
-            - name: {{ $env.name }}
-              value: {{ $env.value }}
+          {{- with .Values.env }}
+            {{- toYaml . | nindent 12 }}
           {{- end }}
           {{- if .Values.sasl.scram.enabled }}
             - name: SCRAM_USERNAME

charts/prometheus-kafka-exporter/values.yaml

@@ -48,9 +48,18 @@ serviceAccount:
   # If not set and create is true, a name is generated using the fullname template
   name:
 
+# Specifies environment variables to be added to the kafka-exporter container.
+# Environment variables can be defined as a list of either key-value pairs or
+# using valueFrom to reference a secret or config map.
 env: []
-# - name: <ENV_VAR_NAME>
-#   value: <value>
+  # - name: <ENV_VAR_NAME>
+  #   value: <value>
+  # - name: PASSWORD
+  #   valueFrom:
+  #     secretKeyRef:
+  #       name: mysecret
+  #       key: password
+  #       optional: false
 
 # List of additional cli arguments to configure kafka-exporter
 # for example: --log.enable-sarama, --log.level=debug, etc.