Declare and use dhcp metric path in nav.metrics.templates

python/nav/dhcp/generic_metrics.py

@@ -2,7 +2,7 @@
 from enum import Enum
 from IPy import IP
 from nav.metrics import carbon, CONFIG
-from nav.metrics.names import escape_metric_name
+from nav.metrics.templates import metric_path_for_subnet_dhcp
 from typing import Iterator
 from datetime import datetime
 
@@ -29,12 +29,6 @@ class DhcpMetricSource:
     specific line of DHCP servers and import the metrics into NAV's
     graphite server. Subclasses need to implement `fetch_metrics`.
     """
-
-    graphite_prefix: str
-
-    def __init__(self, graphite_prefix="nav.dhcp"):
-        self.graphite_prefix = graphite_prefix
-
     def fetch_metrics(self) -> Iterator[DhcpMetric]:
         """
         Fetch DhcpMetrics having keys `TOTAL` and `ASSIGNED` for each subnet of the
@@ -54,7 +48,9 @@ def fetch_metrics_to_graphite(
         """
         graphite_metrics = []
         for metric in self.fetch_metrics():
-            graphite_path = f"{self.graphite_prefix}.{escape_metric_name(metric.subnet_prefix.strNormal())}.{metric.key}"
+            metric_path = metric_path_for_subnet_dhcp(
+                metric.subnet_prefix, str(metric.key)
+            )
             datapoint = (metric.timestamp, metric.value)
-            graphite_metrics.append((graphite_path, datapoint))
+            graphite_metrics.append((metric_path, datapoint))
         carbon.send_metrics_to(graphite_metrics, host, port)

python/nav/metrics/templates.py

@@ -184,3 +184,13 @@ def metric_path_for_multicast_usage(group, sysname):
         group=metric_prefix_for_multicast_group(group),
         sysname=escape_metric_name(sysname),
     )
+
+
+def metric_path_for_subnet_dhcp(subnet_prefix, metric_name):
+    tmpl = "nav.dhcp.{subnet_prefix}.{metric_name}"
+    if hasattr(subnet_prefix, 'strNormal') and callable(subnet_prefix.strNormal):
+        subnet_prefix = subnet_prefix.strNormal()
+    return tmpl.format(
+        subnet_prefix=escape_metric_name(subnet_prefix)
+        metric_name=metric_name
+    )