Add functionality to graph DHCP stats on each VLAN page and Prefix page in NAV

changelog.d/2373.added.md

@@ -0,0 +1 @@
+Show DHCP stats graphs on VLAN and Prefix pages when recent enough DHCP stats are found

python/nav/bin/dhcpstats.py

@@ -15,7 +15,8 @@
 # along with NAV. If not, see <http://www.gnu.org/licenses/>.
 #
 """
-Collects statistics from DHCP servers and sends them to the Carbon backend.
+Collects statistics from DHCP servers and sends them to the Graphite/Carbon
+backend.
 """
 
 import argparse
@@ -25,6 +26,7 @@
 
 from nav.config import getconfig
 from nav.dhcpstats import kea_dhcp
+from nav.dhcpstats.common import GraphiteMetric
 from nav.dhcpstats.errors import CommunicationError
 from nav.errors import ConfigurationError
 from nav.logs import init_generic_logging
@@ -36,7 +38,7 @@
 CONFIGFILE = "dhcpstats.conf"
 PIDFILE = "dhcpstats.pid"
 
-ENDPOINT_CLIENTS = {
+CLIENTS = {
     "kea-dhcp4": partial(kea_dhcp.Client, dhcp_version=4),
 }
 
@@ -66,27 +68,27 @@ def parse_args():
     """
     parser = argparse.ArgumentParser(
         description="Collects statistics from DHCP servers and sends them to the "
-        "Carbon backend",
-        epilog="Statistics are collected from each DHCP API endpoint configured in "
-        "'CONFDIR/dhcpstats.conf', and then sent to the Carbon backend configured in "
-        "'CONFDIR/graphite.conf'.",
+        "Graphite/Carbon backend",
+        epilog="Statistics are collected from each DHCP server configured in "
+        "'CONFDIR/dhcpstats.conf', and then sent to the Graphite/Carbon backend "
+        "configured in 'CONFDIR/graphite.conf'.",
     )
     return parser.parse_args()
 
 
 def collect_stats(config):
     """
-    Collects current stats from each configured endpoint.
+    Collects current stats from each configured server.
 
     :param config: dhcpstats.conf INI-parsed into a dict specifying
-    endpoints to collect metrics from.
+    servers to collect metrics from.
     """
 
     _logger.info("--> Starting stats collection <--")
 
-    all_stats = []
+    all_stats: list[GraphiteMetric] = []
 
-    for client in get_endpoint_clients(config):
+    for client in get_clients(config):
         _logger.info(
             "Collecting stats using %s...",
             client,
@@ -96,13 +98,13 @@ def collect_stats(config):
             fetched_stats = client.fetch_stats()
         except ConfigurationError as err:
             _logger.warning(
-                "%s is badly configured: %s, skipping endpoint...",
+                "%s is badly configured: %s, skipping server...",
                 client,
                 err,
             )
         except CommunicationError as err:
             _logger.warning(
-                "Error while collecting stats using %s: %s, skipping endpoint...",
+                "Error while collecting stats using %s: %s, skipping server...",
                 client,
                 err,
             )
@@ -118,46 +120,48 @@ def collect_stats(config):
     _logger.info("--> Stats collection done <--")
 
 
-def get_endpoint_clients(config):
+def get_clients(config):
     """
-    Yields one client per correctly configured endpoint in config. A section
-    of the config correctly configures an endpoint if:
+    Yields one client per correctly configured server in config. A section
+    of the config correctly configures a server if:
 
-    * Its name starts with 'endpoint_'.
+    * Its name starts with 'endpoint_' or 'server_'.
     * It has the mandatory option 'type'.
     * The value of the 'type' option is mapped to a client initializer
-      by ENDPOINT_CLIENTS, and the client doesn't raise a
+      by the global CLIENTS dictionary, and the client doesn't raise a
       ConfigurationError when it is initialized with the rest of the
       options of the section as keyword arguments.
 
     :param config: dhcpstats.conf INI-parsed into a dict specifying
-    endpoints to collect metrics from.
+    servers to collect metrics from.
     """
     for section, options in config.items():
-        if not section.startswith("endpoint_"):
+        if section.startswith("endpoint_"):
+            server_name = section.removeprefix("endpoint_")
+        elif section.startswith("server_"):
+            server_name = section.removeprefix("server_")
+        else:
             continue
-        endpoint_name = section.removeprefix("endpoint_")
-        endpoint_type = options.get("type")
+        server_type = options.get("type")
         kwargs = {opt: val for opt, val in options.items() if opt != "type"}
         try:
-            cls = ENDPOINT_CLIENTS[endpoint_type]
+            cls = CLIENTS[server_type]
         except KeyError:
             _logger.warning(
-                "Invalid endpoint type '%s' defined in config section [%s], skipping "
-                "endpoint...",
-                endpoint_type,
+                "Invalid server type '%s' defined in config section [%s], skipping "
+                "server...",
+                server_type,
                 section,
             )
             continue
 
         try:
-            client = cls(endpoint_name, **kwargs)
+            client = cls(server_name, **kwargs)
         except (ConfigurationError, TypeError) as err:
             _logger.warning(
-                "Endpoint type '%s' defined in config section [%s] is badly "
-                "configured: %s, skipping endpoint...",
-                endpoint_type,
+                "Section [%s] of %s is badly configured: %s, skipping server...",
                 section,
+                CONFIGFILE,
                 err,
             )
         else: