implement pod stats

Implement pod stats for the local and remote client. Both code paths end
up in infra/abi to allow for code share.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

2 files changed, 89 insertions, 0 deletions

diff --git a/pkg/domain/infra/abi/pods_stats.go b/pkg/domain/infra/abi/pods_stats.go
new file mode 100644
index 000000000..a41c01da0
--- /dev/null
+++ b/pkg/domain/infra/abi/pods_stats.go
@@ -0,0 +1,85 @@
+package abi
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/pkg/cgroups"
+	"github.com/containers/libpod/pkg/domain/entities"
+	"github.com/containers/libpod/pkg/rootless"
+	"github.com/docker/go-units"
+	"github.com/pkg/errors"
+)
+
+// PodStats implements printing stats about pods.
+func (ic *ContainerEngine) PodStats(ctx context.Context, namesOrIds []string, options entities.PodStatsOptions) ([]*entities.PodStatsReport, error) {
+	// Cgroups v2 check for rootless.
+	if rootless.IsRootless() {
+		unified, err := cgroups.IsCgroup2UnifiedMode()
+		if err != nil {
+			return nil, err
+		}
+		if !unified {
+			return nil, errors.New("pod stats is not supported in rootless mode without cgroups v2")
+		}
+	}
+	// Get the (running) pods and convert them to the entities format.
+	pods, err := getPodsByContext(options.All, options.Latest, namesOrIds, ic.Libpod)
+	if err != nil {
+		return nil, errors.Wrap(err, "unable to get list of pods")
+	}
+	return ic.podsToStatsReport(pods)
+}
+
+// podsToStatsReport converts a slice of pods into a corresponding slice of stats reports.
+func (ic *ContainerEngine) podsToStatsReport(pods []*libpod.Pod) ([]*entities.PodStatsReport, error) {
+	reports := []*entities.PodStatsReport{}
+	for i := range pods { // Access by index to prevent potential loop-variable leaks.
+		podStats, err := pods[i].GetPodStats(nil)
+		if err != nil {
+			return nil, err
+		}
+		podID := pods[i].ID()[:12]
+		for j := range podStats {
+			r := entities.PodStatsReport{
+				CPU:      floatToPercentString(podStats[j].CPU),
+				MemUsage: combineHumanValues(podStats[j].MemUsage, podStats[j].MemLimit),
+				Mem:      floatToPercentString(podStats[j].MemPerc),
+				NetIO:    combineHumanValues(podStats[j].NetInput, podStats[j].NetOutput),
+				BlockIO:  combineHumanValues(podStats[j].BlockInput, podStats[j].BlockOutput),
+				PIDS:     pidsToString(podStats[j].PIDs),
+				CID:      podStats[j].ContainerID[:12],
+				Name:     podStats[j].Name,
+				Pod:      podID,
+			}
+			reports = append(reports, &r)
+		}
+	}
+
+	return reports, nil
+}
+
+func combineHumanValues(a, b uint64) string {
+	if a == 0 && b == 0 {
+		return "-- / --"
+	}
+	return fmt.Sprintf("%s / %s", units.HumanSize(float64(a)), units.HumanSize(float64(b)))
+}
+
+func floatToPercentString(f float64) string {
+	strippedFloat, err := libpod.RemoveScientificNotationFromFloat(f)
+	if err != nil || strippedFloat == 0 {
+		// If things go bazinga, return a safe value
+		return "--"
+	}
+	return fmt.Sprintf("%.2f", strippedFloat) + "%"
+}
+
+func pidsToString(pid uint64) string {
+	if pid == 0 {
+		// If things go bazinga, return a safe value
+		return "--"
+	}
+	return fmt.Sprintf("%d", pid)
+}
diff --git a/pkg/domain/infra/tunnel/pods.go b/pkg/domain/infra/tunnel/pods.go
index e7641c077..c193c6752 100644
--- a/pkg/domain/infra/tunnel/pods.go
+++ b/pkg/domain/infra/tunnel/pods.go
@@ -211,3 +211,7 @@ func (ic *ContainerEngine) PodInspect(ctx context.Context, options entities.PodI
 	}
 	return pods.Inspect(ic.ClientCxt, options.NameOrID)
 }
+
+func (ic *ContainerEngine) PodStats(ctx context.Context, namesOrIds []string, options entities.PodStatsOptions) ([]*entities.PodStatsReport, error) {
+	return pods.Stats(ic.ClientCxt, namesOrIds, options)
+}