[Metrics UI] Use CPU Usage limits for Kubernetes pods when available (#58424) (#58906)

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

Author: simianhacker

x-pack/plugins/infra/common/inventory_models/pod/metrics/snapshot/cpu.ts

@@ -7,9 +7,27 @@
 import { SnapshotModel } from '../../../types';
 
 export const cpu: SnapshotModel = {
-  cpu: {
+  cpu_with_limit: {
+    avg: {
+      field: 'kubernetes.pod.cpu.usage.limit.pct',
+    },
+  },
+  cpu_without_limit: {
     avg: {
       field: 'kubernetes.pod.cpu.usage.node.pct',
     },
   },
+  cpu: {
+    bucket_script: {
+      buckets_path: {
+        with_limit: 'cpu_with_limit',
+        without_limit: 'cpu_without_limit',
+      },
+      script: {
+        source: 'params.with_limit > 0.0 ? params.with_limit : params.without_limit',
+        lang: 'painless',
+      },
+      gap_policy: 'skip',
+    },
+  },
 };

x-pack/plugins/infra/common/inventory_models/pod/metrics/tsvb/pod_cpu_usage.ts

@@ -24,9 +24,23 @@ export const podCpuUsage: TSVBMetricModelCreator = (
       metrics: [
         {
           field: 'kubernetes.pod.cpu.usage.node.pct',
-          id: 'avg-cpu-usage',
+          id: 'avg-cpu-without',
           type: 'avg',
         },
+        {
+          field: 'kubernetes.pod.cpu.usage.limit.pct',
+          id: 'avg-cpu-with',
+          type: 'avg',
+        },
+        {
+          id: 'cpu-usage',
+          type: 'calculation',
+          variables: [
+            { id: 'cpu_with', name: 'with_limit', field: 'avg-cpu-with' },
+            { id: 'cpu_without', name: 'without_limit', field: 'avg-cpu-without' },
+          ],
+          script: 'params.with_limit > 0.0 ? params.with_limit : params.without_limit',
+        },
       ],
     },
   ],