runtime: add new command to collect metrics from Kata containers

Add a new command to collect metrics and return metrics to Prometheus.

Signed-off-by: bin liu <bin@hyper.sh>

src/runtime/cli/kata-monitor/main.go

@@ -0,0 +1,59 @@
+// Copyright (c) 2020 Ant Financial
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package main
+
+import (
+	"flag"
+	"net/http"
+	"os"
+	"time"
+
+	kataMonitor "github.com/kata-containers/kata-containers/src/runtime/pkg/kata-monitor"
+	"github.com/sirupsen/logrus"
+)
+
+var metricListenAddr = flag.String("listen-address", ":8090", "The address to listen on for HTTP requests.")
+var containerdAddr = flag.String("containerd-address", "/run/containerd/containerd.sock", "Containerd address to accept client requests.")
+var containerdConfig = flag.String("containerd-conf", "/etc/containerd/config.toml", "Containerd config file.")
+var logLevel = flag.String("log-level", "info", "Log level of logrus(trace/debug/info/warn/error/fatal/panic).")
+
+func main() {
+	flag.Parse()
+
+	// init logrus
+	initLog()
+
+	// create new MAgent
+	ma, err := kataMonitor.NewKataMonitor(*containerdAddr, *containerdConfig)
+	if err != nil {
+		panic(err)
+	}
+
+	// setup handlers, now only metrics is supported
+	http.HandleFunc("/metrics", ma.ProcessMetricsRequest)
+
+	// listening on the server
+	logrus.Fatal(http.ListenAndServe(*metricListenAddr, nil))
+}
+
+// initLog setup logger
+func initLog() {
+	kataMonitorLog := logrus.WithFields(logrus.Fields{
+		"name": "kata-monitor",
+		"pid":  os.Getpid(),
+	})
+
+	// set log level, default to warn
+	level, err := logrus.ParseLevel(*logLevel)
+	if err != nil {
+		level = logrus.WarnLevel
+	}
+
+	kataMonitorLog.Logger.SetLevel(level)
+	kataMonitorLog.Logger.Formatter = &logrus.TextFormatter{TimestampFormat: time.RFC3339Nano}
+
+	kataMonitor.SetLogger(kataMonitorLog)
+}