feat: refactor Grafana alerting rules into a consolidated system module and update individual alert files

hosts/web-arm/modules/grafana/alerting/ram_usage.nix

@@ -1,69 +1,61 @@
 { lib, pkgs, config, ... }:
 {
-  services.grafana.provision.alerting.rules.settings.groups = [
+  grafanaAlertRuleDefinitions = [
     {
-      name = "RAMUsageAlerts";
-      folder = "System Alerts";
-      interval = "1m";
+      uid = "high-ram-usage-alert-uid";
+      title = "HighRAMUsage";
+      condition = "D"; # Condition is now D
 
-      rules = [
+      data = [
+        # Query A: Calculate RAM usage percentage
         {
-          uid = "high-ram-usage-alert-uid";
-          title = "HighRAMUsage";
-          condition = "D"; # Condition is now D
-
-          data = [
-            # Query A: Calculate RAM usage percentage
-            {
-              refId = "A";
-              datasourceUid = "vm-datasource-uid";
-              queryType = "prometheus";
-              relativeTimeRange = { from = 60; to = 0; };
-              model = {
-                expr = ''
-                  (1 - node_memory_MemAvailable_bytes / (node_memory_MemTotal_bytes > 0)) * 100
-                  and node_memory_MemAvailable_bytes
-                  and node_memory_MemTotal_bytes
-                '';
-                legendFormat = "RAM usage on {{instance}} ({{job}})";
-                instant = false;
-              };
-            }
-            # Expression C: Reduce Query A to its last value, preserving labels
-            {
-              refId = "C";
-              datasourceUid = "__expr__";
-              model = {
-                type = "reduce";
-                expression = "A"; # Input is Query A
-                reducer = "last"; # Get the last value of each series in A
-              };
-            }
-            # Expression D: Apply math condition to the reduced values from C
-            {
-              refId = "D";
-              datasourceUid = "__expr__";
-              model = {
-                type = "math";
-                expression = "$C > 90"; # Alert if RAM usage from C is > 90%
-              };
-            }
-          ];
-
-          for = "10m"; # Duration the condition must be met
-          noDataState = "NoData";
-          execErrState = "Error";
-
-          annotations = {
-            summary = "High RAM usage on {{ $labels.instance }}";
-            description = ''RAM usage on {{ $labels.instance }} (job: {{ $labels.job }}) has been above 90% for more than 10 minutes. Current value: {{ if $values.C }}{{ $values.C | humanizePercentage }}{{ else }}N/A{{ end }}%.'';
+          refId = "A";
+          datasourceUid = "vm-datasource-uid";
+          queryType = "prometheus";
+          relativeTimeRange = { from = 60; to = 0; };
+          model = {
+            expr = ''
+              (1 - node_memory_MemAvailable_bytes / (node_memory_MemTotal_bytes > 0)) * 100
+              and node_memory_MemAvailable_bytes
+              and node_memory_MemTotal_bytes
+            '';
+            legendFormat = "RAM usage on {{instance}} ({{job}})";
+            instant = false;
           };
-          labels = {
-            severity = "warning";
-            category = "performance";
+        }
+        # Expression C: Reduce Query A to its last value, preserving labels
+        {
+          refId = "C";
+          datasourceUid = "__expr__";
+          model = {
+            type = "reduce";
+            expression = "A"; # Input is Query A
+            reducer = "last"; # Get the last value of each series in A
+          };
+        }
+        # Expression D: Apply math condition to the reduced values from C
+        {
+          refId = "D";
+          datasourceUid = "__expr__";
+          model = {
+            type = "math";
+            expression = "$C > 90"; # Alert if RAM usage from C is > 90%
           };
         }
       ];
+
+      for = "10m"; # Duration the condition must be met
+      noDataState = "NoData";
+      execErrState = "Error";
+
+      annotations = {
+        summary = "High RAM usage on {{ $labels.instance }}";
+        description = ''RAM usage on {{ $labels.instance }} (job: {{ $labels.job }}) has been above 90% for more than 10 minutes. Current value: {{ if $values.C }}{{ $values.C | humanizePercentage }}{{ else }}N/A{{ end }}%.'';
+      };
+      labels = {
+        severity = "warning";
+        category = "performance";
+      };
     }
   ];
 }