libkpod -> lib rename

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

lib/stats.go

@@ -0,0 +1,111 @@
+package lib
+
+import (
+	"path/filepath"
+	"syscall"
+	"time"
+
+	"strings"
+
+	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/opencontainers/runc/libcontainer"
+)
+
+// ContainerStats contains the statistics information for a running container
+type ContainerStats struct {
+	Container   string
+	CPU         float64
+	cpuNano     uint64
+	systemNano  uint64
+	MemUsage    uint64
+	MemLimit    uint64
+	MemPerc     float64
+	NetInput    uint64
+	NetOutput   uint64
+	BlockInput  uint64
+	BlockOutput uint64
+	PIDs        uint64
+}
+
+// GetContainerStats gets the running stats for a given container
+func (c *ContainerServer) GetContainerStats(ctr *oci.Container, previousStats *ContainerStats) (*ContainerStats, error) {
+	previousCPU := previousStats.cpuNano
+	previousSystem := previousStats.systemNano
+	libcontainerStats, err := c.LibcontainerStats(ctr)
+	if err != nil {
+		return nil, err
+	}
+	cgroupStats := libcontainerStats.CgroupStats
+	stats := new(ContainerStats)
+	stats.Container = ctr.ID()
+	stats.CPU = calculateCPUPercent(libcontainerStats, previousCPU, previousSystem)
+	stats.MemUsage = cgroupStats.MemoryStats.Usage.Usage
+	stats.MemLimit = getMemLimit(cgroupStats.MemoryStats.Usage.Limit)
+	stats.MemPerc = float64(stats.MemUsage) / float64(stats.MemLimit)
+	stats.PIDs = cgroupStats.PidsStats.Current
+	stats.BlockInput, stats.BlockOutput = calculateBlockIO(libcontainerStats)
+	stats.NetInput, stats.NetOutput = getContainerNetIO(libcontainerStats)
+
+	return stats, nil
+}
+
+func loadFactory(root string) (libcontainer.Factory, error) {
+	abs, err := filepath.Abs(root)
+	if err != nil {
+		return nil, err
+	}
+	cgroupManager := libcontainer.Cgroupfs
+	return libcontainer.New(abs, cgroupManager, libcontainer.CriuPath(""))
+}
+
+// getMemory limit returns the memory limit for a given cgroup
+// If the configured memory limit is larger than the total memory on the sys, the
+// physical system memory size is returned
+func getMemLimit(cgroupLimit uint64) uint64 {
+	si := &syscall.Sysinfo_t{}
+	err := syscall.Sysinfo(si)
+	if err != nil {
+		return cgroupLimit
+	}
+
+	physicalLimit := uint64(si.Totalram)
+	if cgroupLimit > physicalLimit {
+		return physicalLimit
+	}
+	return cgroupLimit
+}
+
+// Returns the total number of bytes transmitted and received for the given container stats
+func getContainerNetIO(stats *libcontainer.Stats) (received uint64, transmitted uint64) {
+	for _, iface := range stats.Interfaces {
+		received += iface.RxBytes
+		transmitted += iface.TxBytes
+	}
+	return
+}
+
+func calculateCPUPercent(stats *libcontainer.Stats, previousCPU, previousSystem uint64) float64 {
+	var (
+		cpuPercent  = 0.0
+		cpuDelta    = float64(stats.CgroupStats.CpuStats.CpuUsage.TotalUsage - previousCPU)
+		systemDelta = float64(uint64(time.Now().UnixNano()) - previousSystem)
+	)
+	if systemDelta > 0.0 && cpuDelta > 0.0 {
+		// gets a ratio of container cpu usage total, multiplies it by the number of cores (4 cores running
+		// at 100% utilization should be 400% utilization), and multiplies that by 100 to get a percentage
+		cpuPercent = (cpuDelta / systemDelta) * float64(len(stats.CgroupStats.CpuStats.CpuUsage.PercpuUsage)) * 100
+	}
+	return cpuPercent
+}
+
+func calculateBlockIO(stats *libcontainer.Stats) (read uint64, write uint64) {
+	for _, blkIOEntry := range stats.CgroupStats.BlkioStats.IoServiceBytesRecursive {
+		switch strings.ToLower(blkIOEntry.Op) {
+		case "read":
+			read += blkIOEntry.Value
+		case "write":
+			write += blkIOEntry.Value
+		}
+	}
+	return
+}