TUN-4356: Set AUTOMAXPROCS to the CPU limit when running in a Linux container

vendor/go.uber.org/automaxprocs/internal/cgroups/cgroup.go

@@ -0,0 +1,78 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// +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()
+
+	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)
+}

vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups.go

@@ -0,0 +1,117 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// +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"
+	// _cgroupSubsysCPUAcct is the CPU accounting CGroup subsystem.
+	_cgroupSubsysCPUAcct = "cpuacct"
+	// _cgroupSubsysCPUSet is the CPUSet CGroup subsystem.
+	_cgroupSubsysCPUSet = "cpuset"
+	// _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"
+)
+
+const (
+	_procPathCGroup    = "/proc/self/cgroup"
+	_procPathMountInfo = "/proc/self/mountinfo"
+)
+
+// CGroups is a map that associates each CGroup with its subsystem name.
+type CGroups map[string]*CGroup
+
+// NewCGroups returns a new *CGroups from given `mountinfo` and `cgroup` files
+// under for some process under `/proc` file system (see also proc(5) for more
+// information).
+func NewCGroups(procPathMountInfo, procPathCGroup string) (CGroups, error) {
+	cgroupSubsystems, err := parseCGroupSubsystems(procPathCGroup)
+	if err != nil {
+		return nil, err
+	}
+
+	cgroups := make(CGroups)
+	newMountPoint := func(mp *MountPoint) error {
+		if mp.FSType != _cgroupFSType {
+			return nil
+		}
+
+		for _, opt := range mp.SuperOptions {
+			subsys, exists := cgroupSubsystems[opt]
+			if !exists {
+				continue
+			}
+
+			cgroupPath, err := mp.Translate(subsys.Name)
+			if err != nil {
+				return err
+			}
+			cgroups[opt] = NewCGroup(cgroupPath)
+		}
+
+		return nil
+	}
+
+	if err := parseMountInfo(procPathMountInfo, newMountPoint); err != nil {
+		return nil, err
+	}
+	return cgroups, nil
+}
+
+// NewCGroupsForCurrentProcess returns a new *CGroups instance for the current
+// process.
+func NewCGroupsForCurrentProcess() (CGroups, error) {
+	return NewCGroups(_procPathMountInfo, _procPathCGroup)
+}
+
+// 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
+}

vendor/go.uber.org/automaxprocs/internal/cgroups/doc.go

@@ -0,0 +1,23 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package cgroups provides utilities to access Linux control group (CGroups)
+// parameters (CPU quota, for example) for a given process.
+package cgroups

vendor/go.uber.org/automaxprocs/internal/cgroups/errors.go

@@ -0,0 +1,51 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// +build linux
+
+package cgroups
+
+import "fmt"
+
+type cgroupSubsysFormatInvalidError struct {
+	line string
+}
+
+type mountPointFormatInvalidError struct {
+	line string
+}
+
+type pathNotExposedFromMountPointError struct {
+	mountPoint string
+	root       string
+	path       string
+}
+
+func (err cgroupSubsysFormatInvalidError) Error() string {
+	return fmt.Sprintf("invalid format for CGroupSubsys: %q", err.line)
+}
+
+func (err mountPointFormatInvalidError) Error() string {
+	return fmt.Sprintf("invalid format for MountPoint: %q", err.line)
+}
+
+func (err pathNotExposedFromMountPointError) Error() string {
+	return fmt.Sprintf("path %q is not a descendant of mount point root %q and cannot be exposed from %q", err.path, err.root, err.mountPoint)
+}

vendor/go.uber.org/automaxprocs/internal/cgroups/mountpoint.go

@@ -0,0 +1,166 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// +build linux
+
+package cgroups
+
+import (
+	"bufio"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+const (
+	_mountInfoSep               = " "
+	_mountInfoOptsSep           = ","
+	_mountInfoOptionalFieldsSep = "-"
+)
+
+const (
+	_miFieldIDMountID = iota
+	_miFieldIDParentID
+	_miFieldIDDeviceID
+	_miFieldIDRoot
+	_miFieldIDMountPoint
+	_miFieldIDOptions
+	_miFieldIDOptionalFields
+
+	_miFieldCountFirstHalf
+)
+
+const (
+	_miFieldOffsetFSType = iota
+	_miFieldOffsetMountSource
+	_miFieldOffsetSuperOptions
+
+	_miFieldCountSecondHalf
+)
+
+const _miFieldCountMin = _miFieldCountFirstHalf + _miFieldCountSecondHalf
+
+// MountPoint is the data structure for the mount points in
+// `/proc/$PID/mountinfo`. See also proc(5) for more information.
+type MountPoint struct {
+	MountID        int
+	ParentID       int
+	DeviceID       string
+	Root           string
+	MountPoint     string
+	Options        []string
+	OptionalFields []string
+	FSType         string
+	MountSource    string
+	SuperOptions   []string
+}
+
+// NewMountPointFromLine parses a line read from `/proc/$PID/mountinfo` and
+// returns a new *MountPoint.
+func NewMountPointFromLine(line string) (*MountPoint, error) {
+	fields := strings.Split(line, _mountInfoSep)
+
+	if len(fields) < _miFieldCountMin {
+		return nil, mountPointFormatInvalidError{line}
+	}
+
+	mountID, err := strconv.Atoi(fields[_miFieldIDMountID])
+	if err != nil {
+		return nil, err
+	}
+
+	parentID, err := strconv.Atoi(fields[_miFieldIDParentID])
+	if err != nil {
+		return nil, err
+	}
+
+	for i, field := range fields[_miFieldIDOptionalFields:] {
+		if field == _mountInfoOptionalFieldsSep {
+			fsTypeStart := _miFieldIDOptionalFields + i + 1
+
+			if len(fields) != fsTypeStart+_miFieldCountSecondHalf {
+				return nil, mountPointFormatInvalidError{line}
+			}
+
+			miFieldIDFSType := _miFieldOffsetFSType + fsTypeStart
+			miFieldIDMountSource := _miFieldOffsetMountSource + fsTypeStart
+			miFieldIDSuperOptions := _miFieldOffsetSuperOptions + fsTypeStart
+
+			return &MountPoint{
+				MountID:        mountID,
+				ParentID:       parentID,
+				DeviceID:       fields[_miFieldIDDeviceID],
+				Root:           fields[_miFieldIDRoot],
+				MountPoint:     fields[_miFieldIDMountPoint],
+				Options:        strings.Split(fields[_miFieldIDOptions], _mountInfoOptsSep),
+				OptionalFields: fields[_miFieldIDOptionalFields:(fsTypeStart - 1)],
+				FSType:         fields[miFieldIDFSType],
+				MountSource:    fields[miFieldIDMountSource],
+				SuperOptions:   strings.Split(fields[miFieldIDSuperOptions], _mountInfoOptsSep),
+			}, nil
+		}
+	}
+
+	return nil, mountPointFormatInvalidError{line}
+}
+
+// Translate converts an absolute path inside the *MountPoint's file system to
+// the host file system path in the mount namespace the *MountPoint belongs to.
+func (mp *MountPoint) Translate(absPath string) (string, error) {
+	relPath, err := filepath.Rel(mp.Root, absPath)
+
+	if err != nil {
+		return "", err
+	}
+	if relPath == ".." || strings.HasPrefix(relPath, "../") {
+		return "", pathNotExposedFromMountPointError{
+			mountPoint: mp.MountPoint,
+			root:       mp.Root,
+			path:       absPath,
+		}
+	}
+
+	return filepath.Join(mp.MountPoint, relPath), nil
+}
+
+// parseMountInfo parses procPathMountInfo (usually at `/proc/$PID/mountinfo`)
+// and yields parsed *MountPoint into newMountPoint.
+func parseMountInfo(procPathMountInfo string, newMountPoint func(*MountPoint) error) error {
+	mountInfoFile, err := os.Open(procPathMountInfo)
+	if err != nil {
+		return err
+	}
+	defer mountInfoFile.Close()
+
+	scanner := bufio.NewScanner(mountInfoFile)
+
+	for scanner.Scan() {
+		mountPoint, err := NewMountPointFromLine(scanner.Text())
+		if err != nil {
+			return err
+		}
+		if err := newMountPoint(mountPoint); err != nil {
+			return err
+		}
+	}
+
+	return scanner.Err()
+}

vendor/go.uber.org/automaxprocs/internal/cgroups/subsys.go

@@ -0,0 +1,102 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// +build linux
+
+package cgroups
+
+import (
+	"bufio"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	_cgroupSep       = ":"
+	_cgroupSubsysSep = ","
+)
+
+const (
+	_csFieldIDID = iota
+	_csFieldIDSubsystems
+	_csFieldIDName
+	_csFieldCount
+)
+
+// CGroupSubsys represents the data structure for entities in
+// `/proc/$PID/cgroup`. See also proc(5) for more information.
+type CGroupSubsys struct {
+	ID         int
+	Subsystems []string
+	Name       string
+}
+
+// NewCGroupSubsysFromLine returns a new *CGroupSubsys by parsing a string in
+// the format of `/proc/$PID/cgroup`
+func NewCGroupSubsysFromLine(line string) (*CGroupSubsys, error) {
+	fields := strings.SplitN(line, _cgroupSep, _csFieldCount)
+
+	if len(fields) != _csFieldCount {
+		return nil, cgroupSubsysFormatInvalidError{line}
+	}
+
+	id, err := strconv.Atoi(fields[_csFieldIDID])
+	if err != nil {
+		return nil, err
+	}
+
+	cgroup := &CGroupSubsys{
+		ID:         id,
+		Subsystems: strings.Split(fields[_csFieldIDSubsystems], _cgroupSubsysSep),
+		Name:       fields[_csFieldIDName],
+	}
+
+	return cgroup, nil
+}
+
+// parseCGroupSubsystems parses procPathCGroup (usually at `/proc/$PID/cgroup`)
+// and returns a new map[string]*CGroupSubsys.
+func parseCGroupSubsystems(procPathCGroup string) (map[string]*CGroupSubsys, error) {
+	cgroupFile, err := os.Open(procPathCGroup)
+	if err != nil {
+		return nil, err
+	}
+	defer cgroupFile.Close()
+
+	scanner := bufio.NewScanner(cgroupFile)
+	subsystems := make(map[string]*CGroupSubsys)
+
+	for scanner.Scan() {
+		cgroup, err := NewCGroupSubsysFromLine(scanner.Text())
+		if err != nil {
+			return nil, err
+		}
+		for _, subsys := range cgroup.Subsystems {
+			subsystems[subsys] = cgroup
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return subsystems, nil
+}