Fix incorrect KubevirtVmHighMemoryUsage description

Signed-off-by: João Vilaça <jvilaca@redhat.com>

hack/prom-rule-ci/prom-rules-tests.yaml

@@ -574,7 +574,7 @@ tests:
         alertname: KubevirtVmHighMemoryUsage
         exp_alerts:
           - exp_annotations:
-              description: "Container compute in pod virt-launcher-testvm-123 in namespace ns-test free memory is less than 20 MB and it is close to requested memory"
+              description: "Container compute in pod virt-launcher-testvm-123 in namespace ns-test free memory is less than 50Mi and it is close to requested memory"
               summary: "VM is at risk of being evicted and in serious cases of memory exhaustion being terminated by the runtime."
               runbook_url: "https://kubevirt.io/monitoring/runbooks/KubevirtVmHighMemoryUsage"
             exp_labels:
@@ -601,7 +601,7 @@ tests:
         alertname: KubevirtVmHighMemoryUsage
         exp_alerts:
           - exp_annotations:
-              description: "Container compute in pod virt-launcher-testvm-123 in namespace ns-test free memory is less than 20 MB and it is close to requested memory"
+              description: "Container compute in pod virt-launcher-testvm-123 in namespace ns-test free memory is less than 50Mi and it is close to requested memory"
               summary: "VM is at risk of being evicted and in serious cases of memory exhaustion being terminated by the runtime."
               runbook_url: "https://kubevirt.io/monitoring/runbooks/KubevirtVmHighMemoryUsage"
             exp_labels:
@@ -628,7 +628,7 @@ tests:
         alertname: KubevirtVmHighMemoryUsage
         exp_alerts:
           - exp_annotations:
-              description: "Container compute in pod virt-launcher-testvm-123 in namespace ns-test free memory is less than 20 MB and it is close to requested memory"
+              description: "Container compute in pod virt-launcher-testvm-123 in namespace ns-test free memory is less than 50Mi and it is close to requested memory"
               summary: "VM is at risk of being evicted and in serious cases of memory exhaustion being terminated by the runtime."
               runbook_url: "https://kubevirt.io/monitoring/runbooks/KubevirtVmHighMemoryUsage"
             exp_labels:

pkg/virt-operator/resource/generate/components/prometheus.go

@@ -3,6 +3,7 @@ package components
 import (
 	"errors"
 	"fmt"
+	"k8s.io/apimachinery/pkg/api/resource"
 	"os"
 	"strings"
 
@@ -97,6 +98,8 @@ func NewPrometheusRuleSpec(ns string, workloadUpdatesEnabled bool) *v1.Prometheu
 		return fmt.Sprintf(errorRatioQuery, ns, podName, errorCodeRegex, durationInMinutes, ns, podName, durationInMinutes)
 	}
 
+	fiftyMB := resource.MustParse("50Mi")
+
 	runbookURLTemplate := getRunbookURLTemplate()
 
 	var kubevirtRules []v1.Rule
@@ -383,7 +386,7 @@ func NewPrometheusRuleSpec(ns string, workloadUpdatesEnabled bool) *v1.Prometheu
 			Expr:  intstr.FromString("kubevirt_vm_container_free_memory_bytes_based_on_working_set_bytes < 52428800 or kubevirt_vm_container_free_memory_bytes_based_on_rss < 52428800"),
 			For:   "1m",
 			Annotations: map[string]string{
-				"description": "Container {{ $labels.container }} in pod {{ $labels.pod }} in namespace {{ $labels.namespace }} free memory is less than 20 MB and it is close to requested memory",
+				"description": fmt.Sprintf("Container {{ $labels.container }} in pod {{ $labels.pod }} in namespace {{ $labels.namespace }} free memory is less than %s and it is close to requested memory", fiftyMB.String()),
 				"summary":     "VM is at risk of being evicted and in serious cases of memory exhaustion being terminated by the runtime.",
 				"runbook_url": fmt.Sprintf(runbookURLTemplate, "KubevirtVmHighMemoryUsage"),
 			},