reexec

Documentation

Overview

Package reexec facilitates the busybox style reexec of the docker binary that we require because of the forking limitations of using Go. Handlers can be registered with a name and the argv 0 of the exec of the binary will be used to find and execute custom init paths.

Index

• func Command(args ...string) *exec.Cmd
• func Init() bool
• func Register(name string, initializer func())
• func Self() string

Functions

func Command

func Command(args ...string) *exec.Cmd

Command returns *exec.Cmd which has Path as current binary. Also it setting SysProcAttr.Pdeathsig to SIGTERM. This will use the in-memory version (/proc/self/exe) of the current binary, it is thus safe to delete or replace the on-disk binary (os.Args[0]).

As SysProcAttr.Pdeathsig is set, the signal will be sent to the process when the OS thread which created the process dies. It is the caller's responsibility to ensure that the creating thread is not terminated prematurely. See https://go.dev/issue/27505 for more details.

func Init

func Init() bool

Init is called as the first part of the exec process and returns true if an initialization function was called.

func Register

func Register(name string, initializer func())

Register adds an initialization func under the specified name

func Self

func Self() string

Self returns the path to the current process's binary. Returns "/proc/self/exe".