runtime: add implementation of GetMetrics

add implementation of `GetMetrics` for runtime.

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

src/runtime/virtcontainers/sandbox_metrics.go

@@ -0,0 +1,130 @@
+package virtcontainers
+
+import (
+	mutils "github.com/kata-containers/kata-containers/src/runtime/pkg/utils"
+	"github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/agent/protocols/grpc"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/procfs"
+)
+
+const namespaceHypervisor = "kata_hypervisor"
+const namespaceKatashim = "kata_shim"
+
+var (
+	hypervisorThreads = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: namespaceHypervisor,
+		Name:      "threads",
+		Help:      "Hypervisor process threads.",
+	})
+
+	hypervisorProcStatus = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespaceHypervisor,
+		Name:      "proc_status",
+		Help:      "Hypervisor process status.",
+	},
+		[]string{"item"},
+	)
+
+	hypervisorProcStat = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespaceHypervisor,
+		Name:      "proc_stat",
+		Help:      "Hypervisor process statistics.",
+	},
+		[]string{"item"},
+	)
+
+	hypervisorNetdev = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespaceHypervisor,
+		Name:      "netdev",
+		Help:      "Net devices statistics.",
+	},
+		[]string{"interface", "item"},
+	)
+
+	hypervisorIOStat = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespaceHypervisor,
+		Name:      "io_stat",
+		Help:      "Process IO statistics.",
+	},
+		[]string{"item"},
+	)
+
+	hypervisorOpenFDs = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: namespaceHypervisor,
+		Name:      "fds",
+		Help:      "Open FDs for hypervisor.",
+	})
+
+	agentRpcDurationsHistogram = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: namespaceKatashim,
+		Name:      "agent_rpc_durations_histogram_million_seconds",
+		Help:      "RPC latency distributions.",
+		Buckets:   prometheus.ExponentialBuckets(1, 2, 10),
+	},
+		[]string{"action"},
+	)
+)
+
+func RegMetrics() {
+	prometheus.MustRegister(hypervisorThreads)
+	prometheus.MustRegister(hypervisorProcStatus)
+	prometheus.MustRegister(hypervisorProcStat)
+	prometheus.MustRegister(hypervisorNetdev)
+	prometheus.MustRegister(hypervisorIOStat)
+	prometheus.MustRegister(hypervisorOpenFDs)
+	prometheus.MustRegister(agentRpcDurationsHistogram)
+}
+
+// UpdateRuntimeMetrics update shim/hypervisor's metrics
+func (s *Sandbox) UpdateRuntimeMetrics() error {
+	pids := s.hypervisor.getPids()
+	if len(pids) == 0 {
+		return nil
+	}
+
+	hypervisorPid := pids[0]
+
+	proc, err := procfs.NewProc(hypervisorPid)
+	if err != nil {
+		return err
+	}
+
+	// process FDs
+	if fds, err := proc.FileDescriptorsLen(); err == nil {
+		hypervisorOpenFDs.Set(float64(fds))
+	}
+
+	// process net device statistics
+	if netdev, err := proc.NetDev(); err == nil {
+		// netdev: map[string]NetDevLine
+		for _, v := range netdev {
+			mutils.SetGaugeVecNetDev(hypervisorNetdev, v)
+		}
+	}
+
+	// process statistics
+	if procStat, err := proc.Stat(); err == nil {
+		hypervisorThreads.Set(float64(procStat.NumThreads))
+		mutils.SetGaugeVecProcStat(hypervisorProcStat, procStat)
+	}
+
+	// process status
+	if procStatus, err := proc.NewStatus(); err == nil {
+		mutils.SetGaugeVecProcStatus(hypervisorProcStatus, procStatus)
+	}
+
+	// process IO statistics
+	if ioStat, err := proc.IO(); err == nil {
+		mutils.SetGaugeVecProcIO(hypervisorIOStat, ioStat)
+	}
+
+	return nil
+}
+
+func (s *Sandbox) GetAgentMetrics() (string, error) {
+	r, err := s.agent.getAgentMetrics(&grpc.GetMetricsRequest{})
+	if err != nil {
+		return "", err
+	}
+	return r.Metrics, nil
+}