15873 FIX ucd_cpu_load: Consider the number of CPUs

Change-Id: Ide9425f2b15ac1321ee7e5dab2b798363e88f4b1
Co-authored-by: Moritz Kiemer <[email protected]>

.werks/15873

@@ -0,0 +1,13 @@
+Title: ucd_cpu_load: Consider the number of CPUs
+Class: fix
+Compatible: compat
+Component: checks
+Date: 1697635673
+Edition: cre
+Level: 1
+Version: 2.2.0p18
+
+The number of CPUs in <i>UCD SNMP Daemon: CPU Utilization</i> was hardcoded to 1, which is mostly wrong today.
+
+With this Werk we count the number of CPUs by fetching {HOST-RESOURCES-V2-MIB::hrProcessorFrwID}.
+If this is not available the check falls back to 1 CPU.

cmk/base/plugins/agent_based/ucd_cpu_load.py

@@ -3,16 +3,17 @@
 # This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
 # conditions defined in the file COPYING, which is part of this source code package.
 
-from typing import Optional
+from typing import List
 
 from .agent_based_api.v1 import register, SNMPTree
 from .agent_based_api.v1.type_defs import StringTable
 from .utils.cpu import Load, Section
 from .utils.ucd_hr_detection import UCD
 
 
-def parse_ucd_cpu_load(string_table: StringTable) -> Optional[Section]:
-    if len(string_table) != 3:
+def parse_ucd_cpu_load(string_table: List[StringTable]) -> Section | None:
+    cpu_loads, cpu_count = string_table
+    if len(cpu_loads) != 3:
         return None
     return Section(
         load=Load(
@@ -22,23 +23,33 @@ def parse_ucd_cpu_load(string_table: StringTable) -> Optional[Section]:
                 else float(int_cpu_load_str) / 100.0
                 if int_cpu_load_str
                 else 0
-                for int_cpu_load_str, float_cpu_load_str in string_table
+                for int_cpu_load_str, float_cpu_load_str in cpu_loads
             )
         ),
-        num_cpus=1,
+        num_cpus=len(cpu_count)
+        if cpu_count
+        else 1,  # fallback to 1 if we don't get the number of cpu's from SNMP
     )
 
 
 register.snmp_section(
     name="ucd_cpu_load",
     parsed_section_name="cpu",
     parse_function=parse_ucd_cpu_load,
-    fetch=SNMPTree(
-        base=".1.3.6.1.4.1.2021.10.1",
-        oids=[
-            "5",  # UCD-SNMP-MIB::laLoadInt       Int table
-            "6",  # UCD-SNMP-MIB::laLoadFloat     Float table
-        ],
-    ),
+    fetch=[
+        SNMPTree(
+            base=".1.3.6.1.4.1.2021.10.1",
+            oids=[
+                "5",  # UCD-SNMP-MIB::laLoadInt       Int table
+                "6",  # UCD-SNMP-MIB::laLoadFloat     Float table
+            ],
+        ),
+        SNMPTree(
+            base=".1.3.6.1.2.1.25.3.3.1",
+            oids=[
+                "1",  # HOST-RESOURCES-V2-MIB::hrProcessorFrwID
+            ],
+        ),
+    ],
     detect=UCD,
 )

tests/unit/cmk/base/plugins/agent_based/test_ucd_cpu_load.py

@@ -3,6 +3,8 @@
 # This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
 # conditions defined in the file COPYING, which is part of this source code package.
 
+from typing import List
+
 import pytest
 
 from cmk.base.plugins.agent_based.agent_based_api.v1.type_defs import StringTable
@@ -14,15 +16,18 @@
     ["string_table", "expected_section"],
     [
         pytest.param(
-            [["312", "3.123213"], ["280", "2.78897"], ["145", "1.34563546"]],
+            [
+                [["312", "3.123213"], ["280", "2.78897"], ["145", "1.34563546"]],
+                [[".0.0"], [".0.0"], [".0.0"], [".0.0"]],
+            ],
             Section(
                 load=Load(load1=3.123213, load5=2.78897, load15=1.34563546),
-                num_cpus=1,
+                num_cpus=4,
             ),
             id="complete dataset",
         ),
         pytest.param(
-            [["", "5,234"], ["234", ""], ["", ""]],
+            [[["", "5,234"], ["234", ""], ["", ""]], []],
             Section(
                 load=Load(load1=5.234, load5=2.34, load15=0),
                 num_cpus=1,
@@ -31,5 +36,5 @@
         ),
     ],
 )
-def test_parse_ucd_cpu_load(string_table: StringTable, expected_section: Section) -> None:
+def test_parse_ucd_cpu_load(string_table: List[StringTable], expected_section: Section) -> None:
     assert parse_ucd_cpu_load(string_table) == expected_section