Fix getting memory size in some lshw output

Due to a regression in lshw introduced by
https://github.com/lyonel/lshw/pull/60, there are some versions in the
wild that do not return sizes for memory banks <32GiB. In those cases,
work around the problem by looking at the top-level size (if available)
to find the total size. Previously we assumed that we only needed the
top-level size when there was no list of memory banks.

The issue is fixed upstream by https://github.com/lyonel/lshw/pull/65,
but the erroneous patch is still present in the lshw-B.02.19.2-5.el8
package in CentOS 8.4 and 8.5.

Change-Id: I6eb5981d28b9ae368239af0c1d0ec32ff79d95b3
Story: #2008865
Task: 42395
(cherry picked from commit ed791d97786f4ed37bf7b9f18eac8e2af46c3766)

4 files changed, 210 insertions, 7 deletions

diff --git a/ironic_python_agent/hardware.py b/ironic_python_agent/hardware.py
index abda1f1a..f6ebb92b 100644
--- a/ironic_python_agent/hardware.py
+++ b/ironic_python_agent/hardware.py
@@ -222,16 +222,16 @@ def _calc_memory(sys_dict):
         for core_child in sys_child['children']:
             if not _MEMORY_ID_RE.match(core_child['id']):
                 continue
-            if (not core_child.get("children")
-                    and core_child.get('size')):
+            if core_child.get('size'):
                 value = ("%(size)s %(units)s" % core_child)
                 physical += int(UNIT_CONVERTER(value).to
                                 ('MB').magnitude)
-            for bank in core_child.get('children', ()):
-                if bank.get('size'):
-                    value = ("%(size)s %(units)s" % bank)
-                    physical += int(UNIT_CONVERTER(value).to
-                                    ('MB').magnitude)
+            else:
+                for bank in core_child.get('children', ()):
+                    if bank.get('size'):
+                        value = ("%(size)s %(units)s" % bank)
+                        physical += int(UNIT_CONVERTER(value).to
+                                        ('MB').magnitude)
     return physical
 
 
diff --git a/ironic_python_agent/tests/unit/samples/hardware_samples.py b/ironic_python_agent/tests/unit/samples/hardware_samples.py
index f398f60f..3ab54153 100644
--- a/ironic_python_agent/tests/unit/samples/hardware_samples.py
+++ b/ironic_python_agent/tests/unit/samples/hardware_samples.py
@@ -543,6 +543,190 @@ LSHW_JSON_OUTPUT_V2 = ("""
 }
 """, "")
 
+LSHW_JSON_OUTPUT_NO_MEMORY_BANK_SIZE = ("""
+{
+  "id" : "bumblebee",
+  "class" : "system",
+  "claimed" : true,
+  "handle" : "DMI:0001",
+  "description" : "Rack Mount Chassis",
+  "product" : "ABCD",
+  "vendor" : "ABCD",
+  "version" : "1234",
+  "serial" : "1234",
+  "width" : 64,
+  "configuration" : {
+    "boot" : "normal",
+    "chassis" : "rackmount",
+    "family" : "Intel Grantley EP",
+    "sku" : "NULL",
+    "uuid" : "00010002-0003-0004-0005-000600070008"
+  },
+  "capabilities" : {
+    "smbios-2.8" : "SMBIOS version 2.8",
+    "dmi-2.7" : "DMI version 2.7",
+    "vsyscall32" : "32-bit processes"
+  },
+  "children" : [
+    {
+      "id" : "core",
+      "class" : "bus",
+      "claimed" : true,
+      "handle" : "DMI:0002",
+      "description" : "Motherboard",
+      "product" : "ABCD",
+      "vendor" : "ABCD",
+      "physid" : "0",
+      "version" : "1234",
+      "serial" : "1234",
+      "slot" : "NULL",
+      "children" : [
+        {
+          "id" : "memory:0",
+          "class" : "memory",
+          "claimed" : true,
+          "handle" : "DMI:004A",
+          "description" : "System Memory",
+          "physid" : "4a",
+          "slot" : "System board or motherboard",
+          "units" : "bytes",
+          "size" : 34359738368,
+          "children" : [
+            {
+              "id" : "bank:0",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:004C",
+              "description" : "DIMM Synchronous 2133 MHz (0.5 ns)",
+              "product" : "36ASF2G72PZ-2G1A2",
+              "vendor" : "Micron",
+              "physid" : "0",
+              "serial" : "101B6543",
+              "slot" : "DIMM_A0",
+              "width" : 64,
+              "clock" : 2133000000
+            },
+            {
+              "id" : "bank:1",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:004E",
+              "description" : "DIMM Synchronous [empty]",
+              "product" : "NO DIMM",
+              "vendor" : "NO DIMM",
+              "physid" : "1",
+              "serial" : "NO DIMM",
+              "slot" : "DIMM_A1"
+            },
+            {
+              "id" : "bank:2",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:004F",
+              "description" : "DIMM Synchronous 2133 MHz (0.5 ns)",
+              "product" : "36ASF2G72PZ-2G1A2",
+              "vendor" : "Micron",
+              "physid" : "2",
+              "serial" : "101B654E",
+              "slot" : "DIMM_A2",
+              "width" : 64,
+              "clock" : 2133000000
+            },
+            {
+              "id" : "bank:3",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:0051",
+              "description" : "DIMM Synchronous [empty]",
+              "product" : "NO DIMM",
+              "vendor" : "NO DIMM",
+              "physid" : "3",
+              "serial" : "NO DIMM",
+              "slot" : "DIMM_A3"
+            }
+          ]
+        },
+        {
+          "id" : "memory:1",
+          "class" : "memory",
+          "claimed" : true,
+          "handle" : "DMI:0052",
+          "description" : "System Memory",
+          "physid" : "52",
+          "slot" : "System board or motherboard",
+          "units" : "bytes",
+          "size" : 34359738368,
+          "children" : [
+            {
+              "id" : "bank:0",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:0054",
+              "description" : "DIMM Synchronous 2133 MHz (0.5 ns)",
+              "product" : "36ASF2G72PZ-2G1A2",
+              "vendor" : "Micron",
+              "physid" : "0",
+              "serial" : "101B6545",
+              "slot" : "DIMM_A4",
+              "width" : 64,
+              "clock" : 2133000000
+            },
+            {
+              "id" : "bank:1",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:0056",
+              "description" : "DIMM Synchronous [empty]",
+              "product" : "NO DIMM",
+              "vendor" : "NO DIMM",
+              "physid" : "1",
+              "serial" : "NO DIMM",
+              "slot" : "DIMM_A5"
+            },
+            {
+              "id" : "bank:2",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:0057",
+              "description" : "DIMM Synchronous 2133 MHz (0.5 ns)",
+              "product" : "36ASF2G72PZ-2G1A2",
+              "vendor" : "Micron",
+              "physid" : "2",
+              "serial" : "101B6540",
+              "slot" : "DIMM_A6",
+              "width" : 64,
+              "clock" : 2133000000
+            },
+            {
+              "id" : "bank:3",
+              "class" : "memory",
+              "claimed" : true,
+              "handle" : "DMI:0059",
+              "description" : "DIMM Synchronous [empty]",
+              "product" : "NO DIMM",
+              "vendor" : "NO DIMM",
+              "physid" : "3",
+              "serial" : "NO DIMM",
+              "slot" : "DIMM_A7"
+            }
+          ]
+        },
+        {
+          "id" : "memory:4",
+          "class" : "memory",
+          "physid" : "1"
+        },
+        {
+          "id" : "memory:5",
+          "class" : "memory",
+          "physid" : "2"
+        }
+      ]
+    }
+  ]
+}
+""", "")
+
 LSHW_JSON_OUTPUT_ARM64 = ("""
 {
   "id" : "debian",
diff --git a/ironic_python_agent/tests/unit/test_hardware.py b/ironic_python_agent/tests/unit/test_hardware.py
index 4135985e..ad3a8f65 100644
--- a/ironic_python_agent/tests/unit/test_hardware.py
+++ b/ironic_python_agent/tests/unit/test_hardware.py
@@ -1048,6 +1048,16 @@ class TestGenericHardwareManager(base.IronicAgentTest):
 
     @mock.patch('psutil.virtual_memory', autospec=True)
     @mock.patch.object(utils, 'execute', autospec=True)
+    def test_get_memory_psutil_bank_size(self, mocked_execute, mocked_psutil):
+        mocked_psutil.return_value.total = 3952 * 1024 * 1024
+        mocked_execute.return_value = hws.LSHW_JSON_OUTPUT_NO_MEMORY_BANK_SIZE
+        mem = self.hardware.get_memory()
+
+        self.assertEqual(3952 * 1024 * 1024, mem.total)
+        self.assertEqual(65536, mem.physical_mb)
+
+    @mock.patch('psutil.virtual_memory', autospec=True)
+    @mock.patch.object(utils, 'execute', autospec=True)
     def test_get_memory_psutil_exception_v1(self, mocked_execute,
                                             mocked_psutil):
         mocked_execute.return_value = hws.LSHW_JSON_OUTPUT_V1
diff --git a/releasenotes/notes/lshw-no-memory-bank-size-05ea71987362986e.yaml b/releasenotes/notes/lshw-no-memory-bank-size-05ea71987362986e.yaml
new file mode 100644
index 00000000..ce31079d
--- /dev/null
+++ b/releasenotes/notes/lshw-no-memory-bank-size-05ea71987362986e.yaml
@@ -0,0 +1,9 @@
+---
+fixes:
+  - |
+    The lshw package version B.02.19.2-5 on CentOS 8.4 and 8.5 contains a `bug
+    <https://bugzilla.redhat.com/show_bug.cgi?id=1955250>`_ that prevents the
+    size of individual memory banks from being reported, with the result that
+    the total memory size would be reported as 0 in some places. The total
+    memory size is now taken from lshw's total memory size output (which does
+    not suffer from the same problem) when available.