stats: Expose CPU usage in API

`stats.CPU` is a number representing CPU usage in percents. It is possible
to calculate it from other exposed fields (once they are implemented
correctly) but why to do it, when this is already calculated.

This does not break API, it just adds another field.

Signed-off-by: Matej Marusak <mmarusak@redhat.com>

2 files changed, 63 insertions, 8 deletions

diff --git a/pkg/api/handlers/generic/containers_stats.go b/pkg/api/handlers/generic/containers_stats.go
index 19e2cc882..977979741 100644
--- a/pkg/api/handlers/generic/containers_stats.go
+++ b/pkg/api/handlers/generic/containers_stats.go
@@ -7,7 +7,6 @@ import (
 
 	"github.com/containers/libpod/libpod"
 	"github.com/containers/libpod/libpod/define"
-	"github.com/containers/libpod/pkg/api/handlers"
 	"github.com/containers/libpod/pkg/api/handlers/utils"
 	"github.com/containers/libpod/pkg/cgroups"
 	docker "github.com/docker/docker/api/types"
@@ -58,17 +57,18 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 	}
 
 	var preRead time.Time
-	var preCPUStats docker.CPUStats
+	var preCPUStats CPUStats
 	if query.Stream {
 		preRead = time.Now()
 		systemUsage, _ := cgroups.GetSystemCPUUsage()
-		preCPUStats = docker.CPUStats{
+		preCPUStats = CPUStats{
 			CPUUsage: docker.CPUUsage{
 				TotalUsage:        stats.CPUNano,
 				PercpuUsage:       stats.PerCPU,
 				UsageInKernelmode: stats.CPUSystemNano,
 				UsageInUsermode:   stats.CPUNano - stats.CPUSystemNano,
 			},
+			CPU:            stats.CPU,
 			SystemUsage:    systemUsage,
 			OnlineCPUs:     0,
 			ThrottlingData: docker.ThrottlingData{},
@@ -124,9 +124,8 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 		}
 
 		systemUsage, _ := cgroups.GetSystemCPUUsage()
-
-		s := handlers.Stats{StatsJSON: docker.StatsJSON{
-			Stats: docker.Stats{
+		s := StatsJSON{
+			Stats: Stats{
 				Read:    time.Now(),
 				PreRead: preRead,
 				PidsStats: docker.PidsStats{
@@ -143,13 +142,14 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 					IoTimeRecursive:         nil,
 					SectorsRecursive:        nil,
 				},
-				CPUStats: docker.CPUStats{
+				CPUStats: CPUStats{
 					CPUUsage: docker.CPUUsage{
 						TotalUsage:        cgroupStat.CPU.Usage.Total,
 						PercpuUsage:       cgroupStat.CPU.Usage.PerCPU,
 						UsageInKernelmode: cgroupStat.CPU.Usage.Kernel,
 						UsageInUsermode:   cgroupStat.CPU.Usage.Total - cgroupStat.CPU.Usage.Kernel,
 					},
+					CPU:         stats.CPU,
 					SystemUsage: systemUsage,
 					OnlineCPUs:  uint32(len(cgroupStat.CPU.Usage.PerCPU)),
 					ThrottlingData: docker.ThrottlingData{
@@ -173,7 +173,7 @@ func StatsContainer(w http.ResponseWriter, r *http.Request) {
 			Name:     stats.Name,
 			ID:       stats.ContainerID,
 			Networks: net,
-		}}
+		}
 
 		utils.WriteJSON(w, http.StatusOK, s)
 		if flusher, ok := w.(http.Flusher); ok {
diff --git a/pkg/api/handlers/generic/types.go b/pkg/api/handlers/generic/types.go
new file mode 100644
index 000000000..f068ac011
--- /dev/null
+++ b/pkg/api/handlers/generic/types.go
@@ -0,0 +1,55 @@
+package generic
+
+import (
+	"time"
+
+	docker "github.com/docker/docker/api/types"
+)
+
+// CPUStats aggregates and wraps all CPU related info of container
+type CPUStats struct {
+	// CPU Usage. Linux and Windows.
+	CPUUsage docker.CPUUsage `json:"cpu_usage"`
+
+	// System Usage. Linux only.
+	SystemUsage uint64 `json:"system_cpu_usage,omitempty"`
+
+	// Online CPUs. Linux only.
+	OnlineCPUs uint32 `json:"online_cpus,omitempty"`
+
+	// Usage of CPU in %. Linux only.
+	CPU float64 `json:"cpu"`
+
+	// Throttling Data. Linux only.
+	ThrottlingData docker.ThrottlingData `json:"throttling_data,omitempty"`
+}
+
+// Stats is Ultimate struct aggregating all types of stats of one container
+type Stats struct {
+	// Common stats
+	Read    time.Time `json:"read"`
+	PreRead time.Time `json:"preread"`
+
+	// Linux specific stats, not populated on Windows.
+	PidsStats  docker.PidsStats  `json:"pids_stats,omitempty"`
+	BlkioStats docker.BlkioStats `json:"blkio_stats,omitempty"`
+
+	// Windows specific stats, not populated on Linux.
+	NumProcs     uint32              `json:"num_procs"`
+	StorageStats docker.StorageStats `json:"storage_stats,omitempty"`
+
+	// Shared stats
+	CPUStats    CPUStats           `json:"cpu_stats,omitempty"`
+	PreCPUStats CPUStats           `json:"precpu_stats,omitempty"` // "Pre"="Previous"
+	MemoryStats docker.MemoryStats `json:"memory_stats,omitempty"`
+}
+
+type StatsJSON struct {
+	Stats
+
+	Name string `json:"name,omitempty"`
+	ID   string `json:"id,omitempty"`
+
+	// Networks request version >=1.21
+	Networks map[string]docker.NetworkStats `json:"networks,omitempty"`
+}