support cgroup v2

Author: Curl-Li

consts.go

@@ -92,12 +92,6 @@ var check2name = map[configureType]string{
 	gcHeap:    "GCHeap",
 }
 
-const (
-	cgroupMemLimitPath  = "/sys/fs/cgroup/memory/memory.limit_in_bytes"
-	cgroupCpuQuotaPath  = "/sys/fs/cgroup/cpu/cpu.cfs_quota_us"
-	cgroupCpuPeriodPath = "/sys/fs/cgroup/cpu/cpu.cfs_period_us"
-)
-
 const minCollectCyclesBeforeDumpStart = 10
 
 const (

doc/zh.md

@@ -235,7 +235,7 @@ h, _ := holmes.New(
 ```
 
 ### 在docker 或者cgroup环境下运行 holmes
-
+支持 Cgroup V1, V2 两个版本, 但暂不支持混用。
 ```go
 h, _ := holmes.New(
     holmes.WithCollectInterval("5s"),

internal/cg/cgroups/cgroup.go

@@ -0,0 +1,74 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You 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.
+
+//go:build linux
+// +build linux
+
+package cgroups
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+)
+
+// CGroup represents the data structure for a Linux control group.
+type CGroup struct {
+	path string
+}
+
+// NewCGroup returns a new *CGroup from a given path.
+func NewCGroup(path string) CGroup {
+	return CGroup{path: path}
+}
+
+// Path returns the path of the CGroup*.
+func (cg *CGroup) Path() string {
+	return cg.path
+}
+
+// ParamPath returns the path of the given cgroup param under itself.
+func (cg *CGroup) ParamPath(param string) string {
+	return filepath.Join(cg.path, param)
+}
+
+// readFirstLine reads the first line from a cgroup param file.
+func (cg *CGroup) readFirstLine(param string) (string, error) {
+	paramFile, err := os.Open(cg.ParamPath(param))
+	if err != nil {
+		return "", err
+	}
+	defer paramFile.Close() // nolint: errcheck
+
+	scanner := bufio.NewScanner(paramFile)
+	if scanner.Scan() {
+		return scanner.Text(), nil
+	}
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+	return "", io.ErrUnexpectedEOF
+}
+
+// readInt parses the first line from a cgroup param file as int.
+func (cg *CGroup) readInt(param string) (int, error) {
+	text, err := cg.readFirstLine(param)
+	if err != nil {
+		return 0, err
+	}
+	return strconv.Atoi(text)
+}

internal/cg/cgroups/cgroup_test.go

@@ -0,0 +1,122 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You 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.
+
+//go:build linux
+// +build linux
+
+package cgroups
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCGroupParamPath(t *testing.T) {
+	cgroup := NewCGroup("/sys/fs/cgroup/cpu")
+	assert.Equal(t, "/sys/fs/cgroup/cpu", cgroup.Path())
+	assert.Equal(t, "/sys/fs/cgroup/cpu/cpu.cfs_quota_us", cgroup.ParamPath("cpu.cfs_quota_us"))
+}
+
+func TestCGroupReadFirstLine(t *testing.T) {
+	testTable := []struct {
+		name            string
+		paramName       string
+		expectedContent string
+		shouldHaveError bool
+	}{
+		{
+			name:            "set",
+			paramName:       "cpu.cfs_period_us",
+			expectedContent: "100000",
+			shouldHaveError: false,
+		},
+		{
+			name:            "absent",
+			paramName:       "cpu.stat",
+			expectedContent: "",
+			shouldHaveError: true,
+		},
+		{
+			name:            "empty",
+			paramName:       "cpu.cfs_quota_us",
+			expectedContent: "",
+			shouldHaveError: true,
+		},
+	}
+
+	for _, tt := range testTable {
+		cgroupPath := filepath.Join(testDataCGroupsPath, "v1", "cpu", tt.name)
+		cgroup := NewCGroup(cgroupPath)
+
+		content, err := cgroup.readFirstLine(tt.paramName)
+		assert.Equal(t, tt.expectedContent, content, tt.name)
+
+		if tt.shouldHaveError {
+			assert.Error(t, err, tt.name)
+		} else {
+			assert.NoError(t, err, tt.name)
+		}
+	}
+}
+
+func TestCGroupReadInt(t *testing.T) {
+	testTable := []struct {
+		name            string
+		paramName       string
+		expectedValue   int
+		shouldHaveError bool
+	}{
+		{
+			name:            "set",
+			paramName:       "cpu.cfs_period_us",
+			expectedValue:   100000,
+			shouldHaveError: false,
+		},
+		{
+			name:            "empty",
+			paramName:       "cpu.cfs_quota_us",
+			expectedValue:   0,
+			shouldHaveError: true,
+		},
+		{
+			name:            "invalid",
+			paramName:       "cpu.cfs_quota_us",
+			expectedValue:   0,
+			shouldHaveError: true,
+		},
+		{
+			name:            "absent",
+			paramName:       "cpu.cfs_quota_us",
+			expectedValue:   0,
+			shouldHaveError: true,
+		},
+	}
+
+	for _, tt := range testTable {
+		cgroupPath := filepath.Join(testDataCGroupsPath, "v1", "cpu", tt.name)
+		cgroup := NewCGroup(cgroupPath)
+
+		value, err := cgroup.readInt(tt.paramName)
+		assert.Equal(t, tt.expectedValue, value, "%s/%s", tt.name, tt.paramName)
+
+		if tt.shouldHaveError {
+			assert.Error(t, err, tt.name)
+		} else {
+			assert.NoError(t, err, tt.name)
+		}
+	}
+}

internal/cg/cgroups/cgroups.go

@@ -0,0 +1,105 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You 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.
+
+//go:build linux
+// +build linux
+
+package cgroups
+
+const (
+	// _cgroupFSType is the Linux CGroup file system type used in
+	// `/proc/$PID/mountinfo`.
+	_cgroupFSType = "cgroup"
+	// _cgroupSubsysCPU is the CPU CGroup subsystem.
+	_cgroupSubsysCPU = "cpu"
+	// _cgroupSubsysMemory is the Memory CGroup subsystem.
+	_cgroupSubsysMemory = "memory"
+
+	// _cgroupCPUCFSQuotaUsParam is the file name for the CGroup CFS quota
+	// parameter.
+	_cgroupCPUCFSQuotaUsParam = "cpu.cfs_quota_us"
+	// _cgroupCPUCFSPeriodUsParam is the file name for the CGroup CFS period
+	// parameter.
+	_cgroupCPUCFSPeriodUsParam = "cpu.cfs_period_us"
+	// _cgroupMemLimitParam is the file name for the CGroup CFS memory
+	// parameter.
+	_cgroupMemLimitParam = "memory.limit_in_bytes"
+)
+
+// CGroups is a map that associates each CGroup with its subsystem name.
+type CGroups map[string]CGroup
+
+func newCGroups(mountInfo []*MountPoint, subsystems map[string]*CGroupSubsys) (CGroups, error) {
+	cgroups := make(CGroups)
+	for _, mp := range mountInfo {
+		if mp.FSType != _cgroupFSType {
+			continue
+		}
+		for _, opt := range mp.SuperOptions {
+			subsys, exists := subsystems[opt]
+			if !exists {
+				continue
+			}
+
+			cgroupPath, err := mp.Translate(subsys.Name)
+			if err != nil {
+				return nil, err
+			}
+			cgroups[opt] = NewCGroup(cgroupPath)
+		}
+
+	}
+	return cgroups, nil
+}
+
+// MemLimit returns the memory limit with memory cgroup controller.
+// `memory.max` wat not set, the method returns `(-1, nil)`
+func (cg CGroups) MemLimit() (int, bool, error) {
+	memCGroup, ok := cg[_cgroupSubsysMemory]
+	if !ok {
+		return -1, false, nil
+	}
+	memLimit, err := memCGroup.readInt(_cgroupMemLimitParam)
+	if defined := memLimit > 0; err != nil || !defined {
+		return -1, defined, err
+	}
+	return memLimit, true, nil
+}
+
+// CPUQuota returns the CPU quota applied with the CPU cgroup controller.
+// It is a result of `cpu.cfs_quota_us / cpu.cfs_period_us`. If the value of
+// `cpu.cfs_quota_us` was not set (-1), the method returns `(-1, nil)`.
+func (cg CGroups) CPUQuota() (float64, bool, error) {
+	cpuCGroup, exists := cg[_cgroupSubsysCPU]
+	if !exists {
+		return -1, false, nil
+	}
+
+	cfsQuotaUs, err := cpuCGroup.readInt(_cgroupCPUCFSQuotaUsParam)
+	if defined := cfsQuotaUs > 0; err != nil || !defined {
+		return -1, defined, err
+	}
+
+	cfsPeriodUs, err := cpuCGroup.readInt(_cgroupCPUCFSPeriodUsParam)
+	if err != nil {
+		return -1, false, err
+	}
+
+	return float64(cfsQuotaUs) / float64(cfsPeriodUs), true, nil
+}
+
+func (cg CGroups) Version() string {
+	return _cgroupFSType
+}