Enable functionbeat telemetry (#54267) (#54455)

* Adding placeholder for functionbeat telemetry in test fixture

* Adding placeholder for functionbeat telemetry expectation

* Adding placeholder for aggregating functionbeat telemetry per cluster

* Update test + fixture

* Updating code

x-pack/legacy/plugins/monitoring/server/telemetry_collection/__tests__/fixtures/beats_stats_results.json

@@ -2,6 +2,36 @@
   {
     "hits": {
       "hits": [
+        {
+          "_source" : {
+            "cluster_uuid": "W7hppdX7R229Oy3KQbZrTw",
+            "type": "beats_state",
+            "beats_state" : {
+              "state" : {
+                "functionbeat" : {
+                  "functions": {
+                    "count": 1
+                  }
+                }
+              }
+            }
+          }
+        },
+        {
+          "_source" : {
+            "cluster_uuid": "W7hppdX7R229Oy3KQbZrTw",
+            "type": "beats_state",
+            "beats_state" : {
+              "state" : {
+                "functionbeat" : {
+                  "functions": {
+                    "count": 3
+                  }
+                }
+              }
+            }
+          }
+        },
         {
           "_source" : {
             "cluster_uuid": "W7hppdX7R229Oy3KQbZrTw",

x-pack/legacy/plugins/monitoring/server/telemetry_collection/__tests__/get_beats_stats.js

@@ -168,6 +168,11 @@ describe('Get Beats Stats', () => {
             },
             monitors: 3,
           },
+          functionbeat: {
+            functions: {
+              count: 4,
+            },
+          },
         },
         FlV4ckTxQ0a78hmBkzzc9A: {
           count: 405,

x-pack/legacy/plugins/monitoring/server/telemetry_collection/get_beats_stats.js

@@ -138,6 +138,23 @@ export function processResults(
         }
       }
 
+      const functionbeatState = get(hit, '_source.beats_state.state.functionbeat');
+      if (functionbeatState !== undefined) {
+        if (!clusters[clusterUuid].hasOwnProperty('functionbeat')) {
+          clusters[clusterUuid].functionbeat = {
+            functions: {
+              count: 0,
+            },
+          };
+        }
+
+        clusters[clusterUuid].functionbeat.functions.count += get(
+          functionbeatState,
+          'functions.count',
+          0
+        );
+      }
+
       const stateHost = get(hit, '_source.beats_state.state.host');
       if (stateHost !== undefined) {
         const hostMap = clusterArchitectureMaps[clusterUuid];