Improve stats output

This adds specific types and improves the json format for the marshaled
structure so that it is inline with the output that the spec produce,
camelCase not snake_case.

This should be the last change needed for people to really depend on the
output of this command and ensure that it does not change with any
internal changes instead of just marshaling the libcontainer structure.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

events.go

@@ -11,6 +11,7 @@ import (
 	"github.com/Sirupsen/logrus"
 	"github.com/codegangsta/cli"
 	"github.com/opencontainers/runc/libcontainer"
+	"github.com/opencontainers/runc/libcontainer/cgroups"
 )
 
 // event struct for encoding the event data to json.
@@ -20,9 +21,82 @@ type event struct {
 	Data interface{} `json:"data,omitempty"`
 }
 
+// stats is the runc specific stats structure for stability when encoding and decoding stats.
+type stats struct {
+	Cpu     cpu                `json:"cpu"`
+	Memory  memory             `json:"memory"`
+	Pids    pids               `json:"pids"`
+	Blkio   blkio              `json:"blkio"`
+	Hugetlb map[string]hugetlb `json:"hugetlb"`
+}
+
+type hugetlb struct {
+	Usage   uint64 `json:"usage,omitempty"`
+	Max     uint64 `json:"max,omitempty"`
+	Failcnt uint64 `json:"failcnt"`
+}
+
+type blkioEntry struct {
+	Major uint64 `json:"major,omitempty"`
+	Minor uint64 `json:"minor,omitempty"`
+	Op    string `json:"op,omitempty"`
+	Value uint64 `json:"value,omitempty"`
+}
+
+type blkio struct {
+	IoServiceBytesRecursive []blkioEntry `json:"ioServiceBytesRecursive,omitempty"`
+	IoServicedRecursive     []blkioEntry `json:"ioServicedRecursive,omitempty"`
+	IoQueuedRecursive       []blkioEntry `json:"ioQueueRecursive,omitempty"`
+	IoServiceTimeRecursive  []blkioEntry `json:"ioServiceTimeRecursive,omitempty"`
+	IoWaitTimeRecursive     []blkioEntry `json:"ioWaitTimeRecursive,omitempty"`
+	IoMergedRecursive       []blkioEntry `json:"ioMergedRecursive,omitempty"`
+	IoTimeRecursive         []blkioEntry `json:"ioTimeRecursive,omitempty"`
+	SectorsRecursive        []blkioEntry `json:"sectorsRecursive,omitempty"`
+}
+
+type pids struct {
+	Current uint64 `json:"current,omitempty"`
+	Limit   uint64 `json:"limit,omitempty"`
+}
+
+type throttling struct {
+	Periods          uint64 `json:"periods,omitempty"`
+	ThrottledPeriods uint64 `json:"throttledPeriods,omitempty"`
+	ThrottledTime    uint64 `json:"throttledTime,omitempty"`
+}
+
+type cpuUsage struct {
+	// Units: nanoseconds.
+	Total  uint64   `json:"total,omitempty"`
+	Percpu []uint64 `json:"percpu,omitempty"`
+	Kernel uint64   `json:"kernel"`
+	User   uint64   `json:"user"`
+}
+
+type cpu struct {
+	Usage      cpuUsage   `json:"usage,omitempty"`
+	Throttling throttling `json:"throttling,omitempty"`
+}
+
+type memoryEntry struct {
+	Limit   uint64 `json:"limit"`
+	Usage   uint64 `json:"usage,omitempty"`
+	Max     uint64 `json:"max,omitempty"`
+	Failcnt uint64 `json:"failcnt"`
+}
+
+type memory struct {
+	Cache     uint64            `json:"cache,omitempty"`
+	Usage     memoryEntry       `json:"usage,omitempty"`
+	Swap      memoryEntry       `json:"swap,omitempty"`
+	Kernel    memoryEntry       `json:"kernel,omitempty"`
+	KernelTCP memoryEntry       `json:"kernelTCP,omitempty"`
+	Raw       map[string]uint64 `json:"raw,omitempty"`
+}
+
 var eventsCommand = cli.Command{
 	Name:  "events",
-	Usage: "display container events such as OOM notifications, cpu, memory, IO and network stats",
+	Usage: "display container events such as OOM notifications, cpu, memory, and IO usage statistics",
 	ArgsUsage: `<container-id>
 
 Where "<container-id>" is the name for the instance of the container.`,
@@ -64,7 +138,7 @@ information is displayed once every 5 seconds.`,
 			if err != nil {
 				fatal(err)
 			}
-			events <- &event{Type: "stats", ID: container.ID(), Data: s}
+			events <- &event{Type: "stats", ID: container.ID(), Data: convertLibcontainerStats(s)}
 			close(events)
 			group.Wait()
 			return
@@ -95,7 +169,7 @@ information is displayed once every 5 seconds.`,
 					n = nil
 				}
 			case s := <-stats:
-				events <- &event{Type: "stats", ID: container.ID(), Data: s}
+				events <- &event{Type: "stats", ID: container.ID(), Data: convertLibcontainerStats(s)}
 			}
 			if n == nil {
 				close(events)
@@ -105,3 +179,73 @@ information is displayed once every 5 seconds.`,
 		group.Wait()
 	},
 }
+
+func convertLibcontainerStats(ls *libcontainer.Stats) *stats {
+	cg := ls.CgroupStats
+	if cg == nil {
+		return nil
+	}
+	var s stats
+	s.Pids.Current = cg.PidsStats.Current
+	s.Pids.Limit = cg.PidsStats.Limit
+
+	s.Cpu.Usage.Kernel = cg.CpuStats.CpuUsage.UsageInKernelmode
+	s.Cpu.Usage.User = cg.CpuStats.CpuUsage.UsageInUsermode
+	s.Cpu.Usage.Total = cg.CpuStats.CpuUsage.TotalUsage
+	s.Cpu.Usage.Percpu = cg.CpuStats.CpuUsage.PercpuUsage
+	s.Cpu.Throttling.Periods = cg.CpuStats.ThrottlingData.Periods
+	s.Cpu.Throttling.ThrottledPeriods = cg.CpuStats.ThrottlingData.ThrottledPeriods
+	s.Cpu.Throttling.ThrottledTime = cg.CpuStats.ThrottlingData.ThrottledTime
+
+	s.Memory.Cache = cg.MemoryStats.Cache
+	s.Memory.Kernel = convertMemoryEntry(cg.MemoryStats.KernelUsage)
+	s.Memory.KernelTCP = convertMemoryEntry(cg.MemoryStats.KernelTCPUsage)
+	s.Memory.Swap = convertMemoryEntry(cg.MemoryStats.SwapUsage)
+	s.Memory.Usage = convertMemoryEntry(cg.MemoryStats.Usage)
+	s.Memory.Raw = cg.MemoryStats.Stats
+
+	s.Blkio.IoServiceBytesRecursive = convertBlkioEntry(cg.BlkioStats.IoServiceBytesRecursive)
+	s.Blkio.IoServicedRecursive = convertBlkioEntry(cg.BlkioStats.IoServicedRecursive)
+	s.Blkio.IoQueuedRecursive = convertBlkioEntry(cg.BlkioStats.IoQueuedRecursive)
+	s.Blkio.IoServiceTimeRecursive = convertBlkioEntry(cg.BlkioStats.IoServiceTimeRecursive)
+	s.Blkio.IoWaitTimeRecursive = convertBlkioEntry(cg.BlkioStats.IoWaitTimeRecursive)
+	s.Blkio.IoMergedRecursive = convertBlkioEntry(cg.BlkioStats.IoMergedRecursive)
+	s.Blkio.IoTimeRecursive = convertBlkioEntry(cg.BlkioStats.IoTimeRecursive)
+	s.Blkio.SectorsRecursive = convertBlkioEntry(cg.BlkioStats.SectorsRecursive)
+
+	s.Hugetlb = make(map[string]hugetlb)
+	for k, v := range cg.HugetlbStats {
+		s.Hugetlb[k] = convertHugtlb(v)
+	}
+	return &s
+}
+
+func convertHugtlb(c cgroups.HugetlbStats) hugetlb {
+	return hugetlb{
+		Usage:   c.Usage,
+		Max:     c.MaxUsage,
+		Failcnt: c.Failcnt,
+	}
+}
+
+func convertMemoryEntry(c cgroups.MemoryData) memoryEntry {
+	return memoryEntry{
+		Limit:   c.Limit,
+		Usage:   c.Usage,
+		Max:     c.MaxUsage,
+		Failcnt: c.Failcnt,
+	}
+}
+
+func convertBlkioEntry(c []cgroups.BlkioStatEntry) []blkioEntry {
+	var out []blkioEntry
+	for _, e := range c {
+		out = append(out, blkioEntry{
+			Major: e.Major,
+			Minor: e.Minor,
+			Op:    e.Op,
+			Value: e.Value,
+		})
+	}
+	return out
+}