Added a few extra node rules (#478)

contrib/kube-prometheus/assets/prometheus/rules/node.rules

@@ -8,3 +8,35 @@ ALERT NodeExporterDown
     summary = "node-exporter cannot be scraped",
     description = "Prometheus could not scrape a node-exporter for more than 10m, or node-exporters have disappeared from discovery.",
   }
+ALERT K8SNodeOutOfDisk
+  IF kube_node_status_out_of_disk{condition="true"} == 1
+  LABELS {
+    service = "k8s",
+    severity = "critical"
+  }
+  ANNOTATIONS {
+    summary = "Node ran out of disk space.",
+    description = "{{ $labels.node }} has run out of disk space.",
+  }
+ 
+ALERT K8SNodeMemoryPressure
+  IF kube_node_status_memory_pressure{condition="true"} == 1
+  LABELS {
+    service = "k8s",
+    severity = "warning"
+  }
+  ANNOTATIONS {
+    summary = "Node is under memory pressure.",
+    description = "{{ $labels.node }} is under memory pressure.",
+  }
+ 
+ALERT K8SNodeDiskPressure
+  IF kube_node_status_disk_pressure{condition="true"} == 1
+  LABELS {
+    service = "k8s",
+    severity = "warning"
+  }
+  ANNOTATIONS {
+    summary = "Node is under disk pressure.",
+    description = "{{ $labels.node }} is under disk pressure.",
+  }

contrib/kube-prometheus/manifests/prometheus/prometheus-k8s-rules.yaml

@@ -582,6 +582,38 @@ data:
         summary = "node-exporter cannot be scraped",
         description = "Prometheus could not scrape a node-exporter for more than 10m, or node-exporters have disappeared from discovery.",
       }
+    ALERT K8SNodeOutOfDisk
+      IF kube_node_status_out_of_disk{condition="true"} == 1
+      LABELS {
+        service = "k8s",
+        severity = "critical"
+      }
+      ANNOTATIONS {
+        summary = "Node ran out of disk space.",
+        description = "{{ $labels.node }} has run out of disk space.",
+      }
+     
+    ALERT K8SNodeMemoryPressure
+      IF kube_node_status_memory_pressure{condition="true"} == 1
+      LABELS {
+        service = "k8s",
+        severity = "warning"
+      }
+      ANNOTATIONS {
+        summary = "Node is under memory pressure.",
+        description = "{{ $labels.node }} is under memory pressure.",
+      }
+     
+    ALERT K8SNodeDiskPressure
+      IF kube_node_status_disk_pressure{condition="true"} == 1
+      LABELS {
+        service = "k8s",
+        severity = "warning"
+      }
+      ANNOTATIONS {
+        summary = "Node is under disk pressure.",
+        description = "{{ $labels.node }} is under disk pressure.",
+      }
   prometheus.rules: |+
     ALERT FailedReload
       IF prometheus_config_last_reload_successful == 0