add metrics

Signed-off-by: LiHui <andrewli@yunify.com>

pkg/utils/metrics/metrics.go

@@ -0,0 +1,65 @@
+package metrics
+
+import (
+	"github.com/emicklei/go-restful"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	apimachineryversion "k8s.io/apimachinery/pkg/version"
+	compbasemetrics "k8s.io/component-base/metrics"
+	ksVersion "kubesphere.io/kubesphere/pkg/version"
+	"net/http"
+	"sync"
+)
+
+var (
+	Defaults DefaultMetrics
+	//registerMetrics sync.Once
+	defaultRegistry = compbasemetrics.NewKubeRegistry()
+	// MustRegister registers registerable metrics but uses the defaultRegistry, panic upon the first registration that causes an error
+	MustRegister = defaultRegistry.MustRegister
+	// Register registers a collectable metric but uses the defaultRegistry
+	Register = defaultRegistry.Register
+)
+
+// DefaultMetrics installs the default prometheus metrics handler
+type DefaultMetrics struct{}
+
+// Install adds the DefaultMetrics handler
+func (m DefaultMetrics) Install(c *restful.Container) {
+	register()
+	c.Handle("/kapis/metrics", Handler())
+}
+
+func versionGet() apimachineryversion.Info {
+	info := ksVersion.Get()
+	return apimachineryversion.Info{
+		Major:        info.GitMajor,
+		Minor:        info.GitMinor,
+		GitVersion:   info.GitVersion,
+		GitCommit:    info.GitCommit,
+		GitTreeState: info.GitTreeState,
+		BuildDate:    info.BuildDate,
+		GoVersion:    info.GoVersion,
+		Compiler:     info.Compiler,
+		Platform:     info.Platform,
+	}
+}
+
+// Handler returns an HTTP handler for the DefaultGatherer. It is
+// already instrumented with InstrumentHandler (using "prometheus" as handler
+// name).
+func Handler() http.Handler {
+	return promhttp.InstrumentMetricHandler(prometheus.DefaultRegisterer, promhttp.HandlerFor(defaultRegistry, promhttp.HandlerOpts{}))
+}
+
+var registerMetrics sync.Once
+
+func register() {
+	registerMetrics.Do(func() {
+		defaultRegistry.RawMustRegister(prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{}))
+		defaultRegistry.RawMustRegister(prometheus.NewGoCollector())
+		for _, metric := range metrics {
+			MustRegister(metric)
+		}
+	})
+}