cgroups

Documentation

Index

• Constants
• func EnterPid(cgroupPaths map[string]string, pid int) error
• func FindCgroupMountpoint(subsystem string) (string, error)
• func FindCgroupMountpointAndRoot(subsystem string) (string, string, error)
• func FindCgroupMountpointDir() (string, error)
• func GetAllPids(path string) ([]int, error)
• func GetAllSubsystems() ([]string, error)
• func GetHugePageSize() ([]string, error)
• func GetInitCgroupDir(subsystem string) (string, error)
• func GetPids(path string) ([]int, error)
• func GetThisCgroupDir(subsystem string) (string, error)
• func IsNotFound(err error) bool
• func NewNotFoundError(sub string) error
• func ParseCgroupFile(path string) (map[string]string, error)
• func PathExists(path string) bool
• func RemovePaths(paths map[string]string) (err error)
• func WriteCgroupProc(dir string, pid int) error
• type BlkioStatEntry
• type BlkioStats
• type CpuStats
• type CpuUsage
• type HugetlbStats
• type Manager
• type MemoryData
• type MemoryStats
• type Mount
  • func GetCgroupMounts(all bool) ([]Mount, error)
  • func (m Mount) GetThisCgroupDir(cgroups map[string]string) (string, error)
• type NotFoundError
  • func (e *NotFoundError) Error() string
• type PidsStats
• type Stats
  • func NewStats() *Stats
• type ThrottlingData

Constants

const (
	CgroupProcesses = "cgroup.procs"
)

Functions

func EnterPid

func EnterPid(cgroupPaths map[string]string, pid int) error

func FindCgroupMountpoint

func FindCgroupMountpoint(subsystem string) (string, error)

https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt

func FindCgroupMountpointAndRoot

func FindCgroupMountpointAndRoot(subsystem string) (string, string, error)

func FindCgroupMountpointDir

func FindCgroupMountpointDir() (string, error)

func GetAllPids

func GetAllPids(path string) ([]int, error)

GetAllPids returns all pids, that were added to cgroup at path and to all its subcgroups.

func GetAllSubsystems

func GetAllSubsystems() ([]string, error)

GetAllSubsystems returns all the cgroup subsystems supported by the kernel

func GetHugePageSize

func GetHugePageSize() ([]string, error)

func GetInitCgroupDir

func GetInitCgroupDir(subsystem string) (string, error)

func GetPids

func GetPids(path string) ([]int, error)

GetPids returns all pids, that were added to cgroup at path.

func GetThisCgroupDir

func GetThisCgroupDir(subsystem string) (string, error)

GetThisCgroupDir returns the relative path to the cgroup docker is running in.

func IsNotFound

func IsNotFound(err error) bool

func NewNotFoundError

func NewNotFoundError(sub string) error

func ParseCgroupFile

func ParseCgroupFile(path string) (map[string]string, error)

ParseCgroupFile parses the given cgroup file, typically from /proc/<pid>/cgroup, into a map of subgroups to cgroup names.

func PathExists

func PathExists(path string) bool

func RemovePaths

func RemovePaths(paths map[string]string) (err error)

RemovePaths iterates over the provided paths removing them. We trying to remove all paths five times with increasing delay between tries. If after all there are not removed cgroups - appropriate error will be returned.

func WriteCgroupProc

func WriteCgroupProc(dir string, pid int) error

WriteCgroupProc writes the specified pid into the cgroup's cgroup.procs file

Types

type BlkioStatEntry

type BlkioStatEntry struct {
	Major uint64 `json:"major,omitempty"`
	Minor uint64 `json:"minor,omitempty"`
	Op    string `json:"op,omitempty"`
	Value uint64 `json:"value,omitempty"`
}

type BlkioStats

type BlkioStats struct {
	// number of bytes tranferred to and from the block device
	IoServiceBytesRecursive []BlkioStatEntry `json:"io_service_bytes_recursive,omitempty"`
	IoServicedRecursive     []BlkioStatEntry `json:"io_serviced_recursive,omitempty"`
	IoQueuedRecursive       []BlkioStatEntry `json:"io_queue_recursive,omitempty"`
	IoServiceTimeRecursive  []BlkioStatEntry `json:"io_service_time_recursive,omitempty"`
	IoWaitTimeRecursive     []BlkioStatEntry `json:"io_wait_time_recursive,omitempty"`
	IoMergedRecursive       []BlkioStatEntry `json:"io_merged_recursive,omitempty"`
	IoTimeRecursive         []BlkioStatEntry `json:"io_time_recursive,omitempty"`
	SectorsRecursive        []BlkioStatEntry `json:"sectors_recursive,omitempty"`
}

type CpuStats

type CpuStats struct {
	CpuUsage       CpuUsage       `json:"cpu_usage,omitempty"`
	ThrottlingData ThrottlingData `json:"throttling_data,omitempty"`
}

type CpuUsage

type CpuUsage struct {
	// Total CPU time consumed.
	// Units: nanoseconds.
	TotalUsage uint64 `json:"total_usage,omitempty"`
	// Total CPU time consumed per core.
	// Units: nanoseconds.
	PercpuUsage []uint64 `json:"percpu_usage,omitempty"`
	// Time spent by tasks of the cgroup in kernel mode.
	// Units: nanoseconds.
	UsageInKernelmode uint64 `json:"usage_in_kernelmode"`
	// Time spent by tasks of the cgroup in user mode.
	// Units: nanoseconds.
	UsageInUsermode uint64 `json:"usage_in_usermode"`
}

CpuUsage denotes the usage of a CPU. All CPU stats are aggregate since container inception.

type HugetlbStats

type HugetlbStats struct {
	// current res_counter usage for hugetlb
	Usage uint64 `json:"usage,omitempty"`
	// maximum usage ever recorded.
	MaxUsage uint64 `json:"max_usage,omitempty"`
	// number of times hugetlb usage allocation failure.
	Failcnt uint64 `json:"failcnt"`
}

type Manager

type Manager interface {
	// Applies cgroup configuration to the process with the specified pid
	Apply(pid int) error

	// Returns the PIDs inside the cgroup set
	GetPids() ([]int, error)

	// Returns the PIDs inside the cgroup set & all sub-cgroups
	GetAllPids() ([]int, error)

	// Returns statistics for the cgroup set
	GetStats() (*Stats, error)

	// Toggles the freezer cgroup according with specified state
	Freeze(state configs.FreezerState) error

	// Destroys the cgroup set
	Destroy() error

	// Returns cgroup paths to save in a state file and to be able to
	// restore the object later.
	GetPaths() map[string]string

	// Sets the cgroup as configured.
	Set(container *configs.Config) error
}

type MemoryData

type MemoryData struct {
	Usage    uint64 `json:"usage,omitempty"`
	MaxUsage uint64 `json:"max_usage,omitempty"`
	Failcnt  uint64 `json:"failcnt"`
	Limit    uint64 `json:"limit"`
}

type MemoryStats

type MemoryStats struct {
	// memory used for cache
	Cache uint64 `json:"cache,omitempty"`
	// usage of memory
	Usage MemoryData `json:"usage,omitempty"`
	// usage of memory + swap
	SwapUsage MemoryData `json:"swap_usage,omitempty"`
	// usage of kernel memory
	KernelUsage MemoryData `json:"kernel_usage,omitempty"`
	// usage of kernel TCP memory
	KernelTCPUsage MemoryData `json:"kernel_tcp_usage,omitempty"`

	Stats map[string]uint64 `json:"stats,omitempty"`
}

type Mount

type Mount struct {
	Mountpoint string
	Root       string
	Subsystems []string
}

func GetCgroupMounts

func GetCgroupMounts(all bool) ([]Mount, error)

GetCgroupMounts returns the mounts for the cgroup subsystems. all indicates whether to return just the first instance or all the mounts.

func (Mount) GetThisCgroupDir

func (m Mount) GetThisCgroupDir(cgroups map[string]string) (string, error)

type NotFoundError

type NotFoundError struct {
	Subsystem string
}

func (*NotFoundError) Error

func (e *NotFoundError) Error() string

type PidsStats

type PidsStats struct {
	// number of pids in the cgroup
	Current uint64 `json:"current,omitempty"`
	// active pids hard limit
	Limit uint64 `json:"limit,omitempty"`
}

type Stats

type Stats struct {
	CpuStats    CpuStats    `json:"cpu_stats,omitempty"`
	MemoryStats MemoryStats `json:"memory_stats,omitempty"`
	PidsStats   PidsStats   `json:"pids_stats,omitempty"`
	BlkioStats  BlkioStats  `json:"blkio_stats,omitempty"`
	// the map is in the format "size of hugepage: stats of the hugepage"
	HugetlbStats map[string]HugetlbStats `json:"hugetlb_stats,omitempty"`
}

func NewStats

func NewStats() *Stats

type ThrottlingData

type ThrottlingData struct {
	// Number of periods with throttling active
	Periods uint64 `json:"periods,omitempty"`
	// Number of periods when the container hit its throttling limit.
	ThrottledPeriods uint64 `json:"throttled_periods,omitempty"`
	// Aggregate time the container was throttled for in nanoseconds.
	ThrottledTime uint64 `json:"throttled_time,omitempty"`
}