Add machine created/terminated counters (kubernetes-sigs#213)

go.mod

@@ -1,6 +1,6 @@
 module github.com/aws/karpenter-core
 
-go 1.19
+go 1.20
 
 require (
 	github.com/Pallinder/go-randomdata v1.2.0

hack/toolchain.sh

@@ -11,12 +11,12 @@ main() {
 
 tools() {
     go install github.com/google/go-licenses@v1.2.0
-    go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.49.0
+    go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.51.1
     go install github.com/google/ko@v0.11.2
     go install github.com/mikefarah/yq/v4@v4.24.5
     go install github.com/norwoodj/helm-docs/cmd/helm-docs@v1.8.1
     go install sigs.k8s.io/controller-runtime/tools/setup-envtest@v0.0.0-20220421205612-c162794a9b12
-    go install sigs.k8s.io/controller-tools/cmd/controller-gen@v0.11.2
+    go install sigs.k8s.io/controller-tools/cmd/controller-gen@v0.11.3
     go install github.com/sigstore/cosign/cmd/cosign@v1.10.0
     go install github.com/gohugoio/hugo@v0.97.3+extended
     go install golang.org/x/vuln/cmd/govulncheck@v0.0.0-20220902211423-27dd78d2ca39

pkg/metrics/metrics.go

@@ -20,7 +20,8 @@ import (
 )
 
 const (
-	nodeSubsystem = "nodes"
+	nodeSubsystem    = "nodes"
+	machineSubsystem = "machines"
 )
 
 var (
@@ -46,6 +47,28 @@ var (
 			"reason",
 		},
 	)
+	MachinesCreatedCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: Namespace,
+			Subsystem: machineSubsystem,
+			Name:      "created",
+			Help:      "Number of machines created in total by Karpenter. Labeled by reason the machine was created.",
+		},
+		[]string{
+			"reason",
+		},
+	)
+	MachinesTerminatedCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: Namespace,
+			Subsystem: machineSubsystem,
+			Name:      "terminated",
+			Help:      "Number of machines terminated in total by Karpenter. Labeled by reason the machine was terminated.",
+		},
+		[]string{
+			"reason",
+		},
+	)
 )
 
 func MustRegister() {

pkg/scheduling/requirement.go

@@ -19,7 +19,6 @@ import (
 	"math"
 	"math/rand"
 	"strconv"
-	"time"
 
 	"github.com/samber/lo"
 	v1 "k8s.io/api/core/v1"
@@ -28,10 +27,6 @@ import (
 	"github.com/aws/karpenter-core/pkg/apis/v1alpha5"
 )
 
-func init() {
-	rand.Seed(time.Now().UnixNano())
-}
-
 // Requirement is an efficient represenatation of v1.NodeSelectorRequirement
 type Requirement struct {
 	Key         string