Enhance chart to allow over-riding command-line args to statsd exporter

chart/templates/statsd/statsd-deployment.yaml

@@ -87,8 +87,9 @@ spec:
         - name: statsd
           image: {{ template "statsd_image" . }}
           imagePullPolicy: {{ .Values.images.statsd.pullPolicy }}
-          args:
-            - "--statsd.mapping-config=/etc/statsd-exporter/mappings.yml"
+          {{- if .Values.statsd.args }}
+          args: {{ tpl (toYaml .Values.statsd.args) . | nindent 12 }}
+          {{- end }}
           resources:
 {{ toYaml .Values.statsd.resources | indent 12 }}
           ports:

chart/values.schema.json

@@ -4167,6 +4167,19 @@
                     "additionalProperties": {
                         "type": "string"
                     }
+                },
+                "args": {
+                    "description": "Args to use when running statsd-exporter (templated).",
+                    "type": [
+                        "array",
+                        "null"
+                    ],
+                    "items": {
+                        "type": "string"
+                    },
+                    "default": [
+                        "--statsd.mapping-config=/etc/statsd-exporter/mappings.yml"
+                    ]
                 }
             }
         },

chart/values.yaml

@@ -1331,6 +1331,9 @@ statsd:
   # Max number of old replicasets to retain
   revisionHistoryLimit: ~
 
+  # Arguments for StatsD exporter command.
+  args: ["--statsd.mapping-config=/etc/statsd-exporter/mappings.yml"]
+
   # Create ServiceAccount
   serviceAccount:
     # Specifies whether a ServiceAccount should be created

tests/charts/test_statsd.py

@@ -41,6 +41,9 @@ def test_should_create_statsd_default(self):
             "subPath": "mappings.yml",
         } in jmespath.search("spec.template.spec.containers[0].volumeMounts", docs[0])
 
+        default_args = ["--statsd.mapping-config=/etc/statsd-exporter/mappings.yml"]
+        assert default_args == jmespath.search("spec.template.spec.containers[0].args", docs[0])
+
     def test_should_add_volume_and_volume_mount_when_exist_extra_mappings(self):
         extra_mapping = {
             "match": "airflow.pool.queued_slots.*",
@@ -210,3 +213,12 @@ def test_statsd_configmap_when_exist_override_mappings(self):
 
         assert 1 == len(mappings_yml_obj["mappings"])
         assert "airflow_pool_queued_slots" == mappings_yml_obj["mappings"][0]["name"]
+
+    def test_statsd_args_can_be_overridden(self):
+        args = ["--some-arg=foo"]
+        docs = render_chart(
+            values={"statsd": {"enabled": True, "args": args}},
+            show_only=["templates/statsd/statsd-deployment.yaml"],
+        )
+
+        assert jmespath.search("spec.template.spec.containers[0].args", docs[0]) == args