cgroup2: implement `docker stats`

The following fields are unsupported:

* BlkioStats: all fields other than IoServiceBytesRecursive
* CPUStats: CPUUsage.PercpuUsage
* MemoryStats: MaxUsage and Failcnt

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

api/swagger.yaml

@@ -5564,6 +5564,12 @@ paths:
         If either `precpu_stats.online_cpus` or `cpu_stats.online_cpus` is
         nil then for compatibility with older daemons the length of the
         corresponding `cpu_usage.percpu_usage` array should be used.
+
+        On a cgroup v2 host, the following fields are not set
+        * `blkio_stats`: all fields other than `io_service_bytes_recursive`
+        * `cpu_stats`: `cpu_usage.percpu_usage`
+        * `memory_stats`: `max_usage` and `failcnt`
+        Also, `memory_stats.stats` fields are incompatible with cgroup v1.
       operationId: "ContainerStats"
       produces: ["application/json"]
       responses:

daemon/daemon_unix.go

@@ -17,6 +17,7 @@ import (
 	"time"
 
 	statsV1 "github.com/containerd/cgroups/stats/v1"
+	statsV2 "github.com/containerd/cgroups/v2/stats"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/blkiodev"
 	pblkiodev "github.com/docker/docker/api/types/blkiodev"
@@ -1446,6 +1447,17 @@ func (daemon *Daemon) stats(c *container.Container) (*types.StatsJSON, error) {
 	s := &types.StatsJSON{}
 	s.Read = cs.Read
 	stats := cs.Metrics
+	switch t := stats.(type) {
+	case *statsV1.Metrics:
+		return daemon.statsV1(s, t)
+	case *statsV2.Metrics:
+		return daemon.statsV2(s, t)
+	default:
+		return nil, errors.Errorf("unexpected type of metrics %+v", t)
+	}
+}
+
+func (daemon *Daemon) statsV1(s *types.StatsJSON, stats *statsV1.Metrics) (*types.StatsJSON, error) {
 	if stats.Blkio != nil {
 		s.BlkioStats = types.BlkioStats{
 			IoServiceBytesRecursive: copyBlkioEntry(stats.Blkio.IoServiceBytesRecursive),
@@ -1539,6 +1551,104 @@ func (daemon *Daemon) stats(c *container.Container) (*types.StatsJSON, error) {
 	return s, nil
 }
 
+func (daemon *Daemon) statsV2(s *types.StatsJSON, stats *statsV2.Metrics) (*types.StatsJSON, error) {
+	if stats.Io != nil {
+		var isbr []types.BlkioStatEntry
+		for _, re := range stats.Io.Usage {
+			isbr = append(isbr,
+				types.BlkioStatEntry{
+					Major: re.Major,
+					Minor: re.Minor,
+					Op:    "read",
+					Value: re.Rbytes,
+				},
+				types.BlkioStatEntry{
+					Major: re.Major,
+					Minor: re.Minor,
+					Op:    "write",
+					Value: re.Wbytes,
+				},
+			)
+		}
+		s.BlkioStats = types.BlkioStats{
+			IoServiceBytesRecursive: isbr,
+			// Other fields are unsupported
+		}
+	}
+
+	if stats.CPU != nil {
+		s.CPUStats = types.CPUStats{
+			CPUUsage: types.CPUUsage{
+				TotalUsage: stats.CPU.UsageUsec * 1000,
+				// PercpuUsage is not supported
+				UsageInKernelmode: stats.CPU.SystemUsec * 1000,
+				UsageInUsermode:   stats.CPU.UserUsec * 1000,
+			},
+			ThrottlingData: types.ThrottlingData{
+				Periods:          stats.CPU.NrPeriods,
+				ThrottledPeriods: stats.CPU.NrThrottled,
+				ThrottledTime:    stats.CPU.ThrottledUsec * 1000,
+			},
+		}
+	}
+
+	if stats.Memory != nil {
+		raw := make(map[string]uint64)
+		raw["anon"] = stats.Memory.Anon
+		raw["file"] = stats.Memory.File
+		raw["kernel_stack"] = stats.Memory.KernelStack
+		raw["slab"] = stats.Memory.Slab
+		raw["sock"] = stats.Memory.Sock
+		raw["shmem"] = stats.Memory.Shmem
+		raw["file_mapped"] = stats.Memory.FileMapped
+		raw["file_dirty"] = stats.Memory.FileDirty
+		raw["file_writeback"] = stats.Memory.FileWriteback
+		raw["anon_thp"] = stats.Memory.AnonThp
+		raw["inactive_anon"] = stats.Memory.InactiveAnon
+		raw["active_anon"] = stats.Memory.ActiveAnon
+		raw["inactive_file"] = stats.Memory.InactiveFile
+		raw["active_file"] = stats.Memory.ActiveFile
+		raw["unevictable"] = stats.Memory.Unevictable
+		raw["slab_reclaimable"] = stats.Memory.SlabReclaimable
+		raw["slab_unreclaimable"] = stats.Memory.SlabUnreclaimable
+		raw["pgfault"] = stats.Memory.Pgfault
+		raw["pgmajfault"] = stats.Memory.Pgmajfault
+		raw["workingset_refault"] = stats.Memory.WorkingsetRefault
+		raw["workingset_activate"] = stats.Memory.WorkingsetActivate
+		raw["workingset_nodereclaim"] = stats.Memory.WorkingsetNodereclaim
+		raw["pgrefill"] = stats.Memory.Pgrefill
+		raw["pgscan"] = stats.Memory.Pgscan
+		raw["pgsteal"] = stats.Memory.Pgsteal
+		raw["pgactivate"] = stats.Memory.Pgactivate
+		raw["pgdeactivate"] = stats.Memory.Pgdeactivate
+		raw["pglazyfree"] = stats.Memory.Pglazyfree
+		raw["pglazyfreed"] = stats.Memory.Pglazyfreed
+		raw["thp_fault_alloc"] = stats.Memory.ThpFaultAlloc
+		raw["thp_collapse_alloc"] = stats.Memory.ThpCollapseAlloc
+		s.MemoryStats = types.MemoryStats{
+			// Stats is not compatible with v1
+			Stats: raw,
+			Usage: stats.Memory.Usage,
+			// MaxUsage is not supported
+			Limit: stats.Memory.UsageLimit,
+			// TODO: Failcnt
+		}
+		// if the container does not set memory limit, use the machineMemory
+		if s.MemoryStats.Limit > daemon.machineMemory && daemon.machineMemory > 0 {
+			s.MemoryStats.Limit = daemon.machineMemory
+		}
+	}
+
+	if stats.Pids != nil {
+		s.PidsStats = types.PidsStats{
+			Current: stats.Pids.Current,
+			Limit:   stats.Pids.Limit,
+		}
+	}
+
+	return s, nil
+}
+
 // setDefaultIsolation determines the default isolation mode for the
 // daemon to run in. This is only applicable on Windows
 func (daemon *Daemon) setDefaultIsolation() error {

libcontainerd/types/types_linux.go

@@ -3,7 +3,6 @@ package types // import "github.com/docker/docker/libcontainerd/types"
 import (
 	"time"
 
-	statsV1 "github.com/containerd/cgroups/stats/v1"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 )
 
@@ -12,14 +11,17 @@ type Summary struct{}
 
 // Stats holds metrics properties as returned by containerd
 type Stats struct {
-	Read    time.Time
-	Metrics *statsV1.Metrics
+	Read time.Time
+	// Metrics is expected to be either one of:
+	// * github.com/containerd/cgroups/stats/v1.Metrics
+	// * github.com/containerd/cgroups/stats/v2.Metrics
+	Metrics interface{}
 }
 
 // InterfaceToStats returns a stats object from the platform-specific interface.
 func InterfaceToStats(read time.Time, v interface{}) *Stats {
 	return &Stats{
-		Metrics: v.(*statsV1.Metrics),
+		Metrics: v,
 		Read:    read,
 	}
 }

vendor/github.com/containerd/cgroups/v2/stats/doc.go

@@ -0,0 +1,17 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package stats

vendor/github.com/containerd/cgroups/v2/stats/metrics.proto

@@ -0,0 +1,96 @@
+syntax = "proto3";
+
+package io.containerd.cgroups.v2;
+
+ import "gogoproto/gogo.proto";
+
+message Metrics {
+	PidsStat pids = 1;
+	CPUStat cpu = 2 [(gogoproto.customname) = "CPU"];
+	MemoryStat memory = 4;
+	RdmaStat rdma = 5;
+	IOStat io = 6;
+	repeated HugeTlbStat hugetlb = 7;
+}
+
+message PidsStat {
+	uint64 current = 1;
+	uint64 limit = 2;
+}
+
+message CPUStat {
+	uint64 usage_usec  = 1;
+	uint64 user_usec = 2;
+	uint64 system_usec = 3;
+	uint64 nr_periods = 4;
+	uint64 nr_throttled = 5;
+	uint64 throttled_usec = 6;
+}
+
+message MemoryStat {
+	uint64 anon = 1;
+	uint64 file = 2;
+	uint64 kernel_stack = 3;
+	uint64 slab = 4;
+	uint64 sock = 5;
+	uint64 shmem = 6;
+	uint64 file_mapped = 7;
+	uint64 file_dirty = 8;
+	uint64 file_writeback = 9;
+	uint64 anon_thp = 10;
+	uint64 inactive_anon = 11;
+	uint64 active_anon = 12;
+	uint64 inactive_file = 13;
+	uint64 active_file = 14;
+	uint64 unevictable = 15;
+	uint64 slab_reclaimable = 16;
+	uint64 slab_unreclaimable = 17;
+	uint64 pgfault = 18;
+	uint64 pgmajfault = 19;
+	uint64 workingset_refault = 20;
+	uint64 workingset_activate = 21;
+	uint64 workingset_nodereclaim = 22;
+	uint64 pgrefill = 23;
+	uint64 pgscan = 24;
+	uint64 pgsteal = 25;
+	uint64 pgactivate = 26;
+	uint64 pgdeactivate = 27;
+	uint64 pglazyfree = 28;
+	uint64 pglazyfreed = 29;
+	uint64 thp_fault_alloc = 30;
+	uint64 thp_collapse_alloc = 31;
+	uint64 usage = 32;
+	uint64 usage_limit = 33;
+	uint64 swap_usage = 34;
+	uint64 swap_limit = 35;
+}
+
+message RdmaStat {
+	repeated RdmaEntry current = 1;
+	repeated RdmaEntry limit = 2;
+}
+
+message RdmaEntry {
+	string device = 1;
+	uint32 hca_handles = 2;
+	uint32 hca_objects = 3;
+}
+
+message IOStat {
+	repeated IOEntry usage = 1;
+}
+
+message IOEntry {
+	uint64 major = 1;
+	uint64 minor = 2;
+	uint64 rbytes = 3;
+	uint64 wbytes = 4;
+	uint64 rios = 5;
+	uint64 wios = 6;
+}
+
+message HugeTlbStat {
+	uint64 current = 1;
+	uint64 max = 2;
+	string pagesize = 3;
+}