namespaces

Documentation

Overview

Package namespaces provides functions to render information of Linux namespaces and cgroups.

To enable debug info, set namespaces.DEBUG to true.

For a full guide visit https://github.com/mhausenblas/cinf

Index

• Variables
• func Gather()
• func LookupCG(cgspec string)
• func LookupNS(targetns string)
• func LookupPID(pid string)
• func MonitorPID(monspec string)
• func Showall()
• type NSTYPE
• type Namespace
• type Process

Variables

var (
	DEBUG bool
	NS    []NSTYPE

	MAX_COMMAND_LEN int
)

Functions

func Gather

func Gather()

Gather reads out process-related info from /proc and fills the global namespaces map with it. Note that only filenames that match the [0-9]* pattern are considered here since those are the ones representing processes, with the filename being the PID.

Example:

namespaces.Gather()

func LookupCG

func LookupCG(cgspec string)

LookupCG displays details about a cgroup a process belongs to. Note that cgspec is expected to be in the format PID:CGROUP_HIERARCHY with allowed values for CGROUP_HIERARCHY being the cgroups v1 hierarchy values as found in /proc/groups - see http://man7.org/linux/man-pages/man7/cgroups.7.html for more infos.

Example:

namespaces.LookupCG("1000:2")

func LookupNS

func LookupNS(targetns string)

LookupNS displays details about a specific namespace.

Example:

namespaces.LookupNS("4026532198")

func LookupPID

func LookupPID(pid string)

LookupPID displays the namespaces a process is in.

Example:

namespaces.LookupPID("1000")

func MonitorPID

func MonitorPID(monspec string)

MonitorPID monitors control files values of cgroup a process belongs to. Note that monspec is expected to be in the format PID:CF1,CF2,… with allowed values for CFx being the cgroups control files as described in http://man7.org/linux/man-pages/man7/cgroups.7.html

Example:

namespaces.MonitorPID("1000:memory.usage_in_bytes,memory.max_usage_in_bytes")

func Showall

func Showall()

Showall displays details about all active namespaces. For example:

namespaces.Showall()

Types

type NSTYPE

type NSTYPE string

const (
	NS_MOUNT  NSTYPE = "mnt"    // CLONE_NEWNS, filesystem mount points
	NS_UTS    NSTYPE = "uts"    // CLONE_NEWUTS, nodename and NIS domain name
	NS_IPC    NSTYPE = "ipc"    // CLONE_NEWIPC, interprocess communication
	NS_PID    NSTYPE = "pid"    // CLONE_NEWPID, process ID number space isolation
	NS_NET    NSTYPE = "net"    // CLONE_NEWNET, network system resources
	NS_USER   NSTYPE = "user"   // CLONE_NEWUSER, user and group ID number space isolation
	NS_CGROUP NSTYPE = "cgroup" // CLONE_NEWCGROUP, cgroup root directory
)

The supported namespaces

type Namespace

type Namespace struct {
	Type NSTYPE
	Id   string
}

type Process

type Process struct {
	Pid     string
	PPid    string
	Name    string
	State   string
	Threads string
	Cgroups string
	Uids    string
	Command string
}