launch

Documentation

Index

• Constants
• Variables
• func EscapeID(id string) string
• func GetMetadataFilePath(layersDir string) string
• func ProcessPath(pType string) string
• type BashShell
  • func (b *BashShell) Launch(proc ShellProcess) error
• type Buildpack
• type CmdShell
  • func (c *CmdShell) Launch(proc ShellProcess) error
• type Env
• type ExecD
• type ExecDRunner
  • func NewExecDRunner() *ExecDRunner
  • func (e *ExecDRunner) ExecD(path string, env Env) error
• type ExecFunc
• type Launcher
  • func (l *Launcher) Launch(self string, cmd []string) error
  • func (l *Launcher) LaunchProcess(self string, proc Process) error
  • func (l *Launcher) ProcessFor(cmd []string) (Process, error)
• type Metadata
  • func (m Metadata) FindProcessType(pType string) (Process, bool)
• type Process
  • func (p Process) NoDefault() Process
• type Shell
• type ShellProcess

Constants

const (
	CNBDir = `/cnb`
)

Variables

var (
	LifecycleDir = filepath.Join(CNBDir, "lifecycle")
	ProcessDir   = filepath.Join(CNBDir, "process")
	LauncherPath = filepath.Join(LifecycleDir, "launcher"+exe)
)

var (
	OSExecFunc   = syscall.Exec
	DefaultShell = &BashShell{Exec: OSExecFunc}
)

Functions

func EscapeID

func EscapeID(id string) string

func GetMetadataFilePath

func GetMetadataFilePath(layersDir string) string

func ProcessPath

func ProcessPath(pType string) string

ProcessPath returns the absolute path to the symlink for a given process type

Types

type BashShell

type BashShell struct {
	Exec ExecFunc
}

func (*BashShell) Launch

func (b *BashShell) Launch(proc ShellProcess) error

Launch launches the given ShellProcess with Bash

It shall execute a Bash command that sources profile scripts and then executes the process in a nested Bash command When ShellProcess.Script is true nested Bash script shall be proc.Command with proc.Args provided as argument to Bash When ShellProcess.Script is false a Bash command shall be contructed from proc.Command and proc.Args

type Buildpack

type Buildpack struct {
	API string `toml:"api"`
	ID  string `toml:"id"`
}

type CmdShell

type CmdShell struct {
	Exec ExecFunc
}

func (*CmdShell) Launch

func (c *CmdShell) Launch(proc ShellProcess) error

Launch launches the given ShellProcess with cmd

type Env

type Env interface {
	AddEnvDir(envDir string, defaultAction env.ActionType) error
	AddRootDir(baseDir string) error
	Get(string) string
	List() []string
	Set(name, k string)
}

type ExecD

type ExecD interface {
	ExecD(path string, env Env) error
}

type ExecDRunner

type ExecDRunner struct {
	Out, Err io.Writer // Out and Err can be used to configure Stdout and Stderr processes run by ExecDRunner.
}

ExecDRunner is responsible for running ExecD binaries.

func NewExecDRunner

func NewExecDRunner() *ExecDRunner

NewExecDRunner creates an ExecDRunner with Out and Err set to stdout and stderr

func (*ExecDRunner) ExecD

func (e *ExecDRunner) ExecD(path string, env Env) error

ExecD executes the executable file at path and sets the returned variables in env. The executable at path should implement the ExecD interface in the buildpack specification https://github.com/buildpacks/spec/blob/main/buildpack.md#execd

type ExecFunc

type ExecFunc func(argv0 string, argv []string, envv []string) error

type Launcher

type Launcher struct {
	AppDir             string
	Buildpacks         []Buildpack
	DefaultProcessType string
	Env                Env
	Exec               ExecFunc
	ExecD              ExecD
	Shell              Shell
	LayersDir          string
	PlatformAPI        *api.Version
	Processes          []Process
	Setenv             func(string, string) error
}

func (*Launcher) Launch

func (l *Launcher) Launch(self string, cmd []string) error

Launch uses cmd to select a process and launches that process. For direct=false processes, self is used to set argv0 during profile script execution

func (*Launcher) LaunchProcess

func (l *Launcher) LaunchProcess(self string, proc Process) error

LaunchProcess launches the provided process. For direct=false processes, self is used to set argv0 during profile script execution

func (*Launcher) ProcessFor

func (l *Launcher) ProcessFor(cmd []string) (Process, error)

ProcessFor creates a process from container cmd

If the Platform API if 0.4 or greater and DefaultProcess is set:
  * The default process is returned with `cmd` appended to the process args
If the Platform API is less than 0.4
  * If there is exactly one argument and it matches a process type, it returns that process.
  * If cmd is empty, it returns the default process
Else
  * it constructs a new process from cmd
  * If the first element in cmd is `cmd` the process shall be direct

type Metadata

type Metadata struct {
	Processes  []Process   `toml:"processes" json:"processes"`
	Buildpacks []Buildpack `toml:"buildpacks" json:"buildpacks"`
}

func (Metadata) FindProcessType

func (m Metadata) FindProcessType(pType string) (Process, bool)

type Process

type Process struct {
	Type             string   `toml:"type" json:"type"`
	Command          string   `toml:"command" json:"command"`
	Args             []string `toml:"args" json:"args"`
	Direct           bool     `toml:"direct" json:"direct"`
	Default          bool     `toml:"default,omitempty" json:"default,omitempty"`
	BuildpackID      string   `toml:"buildpack-id" json:"buildpackID"`
	WorkingDirectory string   `toml:"working-dir,omitempty" json:"working-dir,omitempty"`
}

func (Process) NoDefault

func (p Process) NoDefault() Process

type Shell

type Shell interface {
	Launch(ShellProcess) error
}

type ShellProcess

type ShellProcess struct {
	Script           bool // Script indicates whether Command is a script or should be a token in a generated script
	Args             []string
	Command          string
	Caller           string // Caller used to set argv0 for Bash profile scripts and is ignored in Cmd
	Profiles         []string
	Env              []string
	WorkingDirectory string
}