From dd86128e0dff1c4261d23b76e0ad0bcdabd10dc6 Mon Sep 17 00:00:00 2001
From: Kazuyoshi Kato <katokazu@amazon.com>
Date: Fri, 11 Nov 2022 18:10:01 +0000
Subject: [PATCH] Convert hcsshim's stats to cgroups' stats

Since hcsshim still uses containerd/cgroups 1.x which uses
gogo/protobuf.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>
---
 cmd/ctr/commands/tasks/metrics.go | 46 +++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 11 deletions(-)

diff --git a/cmd/ctr/commands/tasks/metrics.go b/cmd/ctr/commands/tasks/metrics.go
index b2c18f296..3fd9c4639 100644
--- a/cmd/ctr/commands/tasks/metrics.go
+++ b/cmd/ctr/commands/tasks/metrics.go
@@ -24,15 +24,16 @@ import (
 	"text/tabwriter"
 
 	wstats "github.com/Microsoft/hcsshim/cmd/containerd-shim-runhcs-v1/stats"
-	v1 "github.com/containerd/cgroups/stats/v1"
-	v2 "github.com/containerd/cgroups/v2/stats"
+	v1 "github.com/containerd/cgroups/v3/cgroup1/stats"
+	v2 "github.com/containerd/cgroups/v3/cgroup2/stats"
 	"github.com/containerd/containerd/cmd/ctr/commands"
+	"github.com/containerd/containerd/protobuf/proto"
 	"github.com/containerd/typeurl"
 	"github.com/urfave/cli"
 )
 
 func init() {
-	// metricsCommand is only added on Linux as github.com/containerd/cgroups
+	// metricsCommand is only added on Linux as github.com/containerd/cgroups/v3
 	// does not compile on darwin or windows
 	Command.Subcommands = append(Command.Subcommands, metricsCommand)
 }
@@ -103,14 +104,9 @@ var metricsCommand = cli.Command{
 			} else if data2 != nil {
 				printCgroup2MetricsTable(w, data2)
 			} else {
-				if windowsStats.GetLinux() != nil {
-					printCgroupMetricsTable(w, windowsStats.GetLinux())
-				} else if windowsStats.GetWindows() != nil {
-					printWindowsContainerStatistics(w, windowsStats.GetWindows())
-				}
-				// Print VM stats if its isolated
-				if windowsStats.VM != nil {
-					printWindowsVMStatistics(w, windowsStats.VM)
+				err := printWindowsStats(w, windowsStats)
+				if err != nil {
+					return fmt.Errorf("cannot convert metrics data from windows.Statistics: %w", err)
 				}
 			}
 			return w.Flush()
@@ -166,6 +162,34 @@ func printCgroup2MetricsTable(w *tabwriter.Writer, data *v2.Metrics) {
 	}
 }
 
+func printWindowsStats(w *tabwriter.Writer, windowsStats *wstats.Statistics) error {
+	if windowsStats.GetLinux() != nil {
+		var stats v1.Metrics
+
+		// It cannot be casted to v1.Metrics since windowsStats is still generated by gogo/protobuf.
+		linux := windowsStats.GetLinux()
+
+		// But Marshal/Unmarshal works because the underlying protobuf message is compatible.
+		data, err := linux.Marshal()
+		if err != nil {
+			return err
+		}
+		err = proto.Unmarshal(data, &stats)
+		if err != nil {
+			return err
+		}
+
+		printCgroupMetricsTable(w, &stats)
+	} else if windowsStats.GetWindows() != nil {
+		printWindowsContainerStatistics(w, windowsStats.GetWindows())
+	}
+	// Print VM stats if its isolated
+	if windowsStats.VM != nil {
+		printWindowsVMStatistics(w, windowsStats.VM)
+	}
+	return nil
+}
+
 func printWindowsContainerStatistics(w *tabwriter.Writer, stats *wstats.WindowsContainerStatistics) {
 	fmt.Fprintf(w, "METRIC\tVALUE\t\n")
 	fmt.Fprintf(w, "timestamp\t%s\t\n", stats.Timestamp)