entrypoint

type Entrypointer struct {
	// Entrypoint is the original specified entrypoint, if any.
	Entrypoint string
	// Args are the original specified args, if any.
	Args []string
	// WaitFile is the file to wait for. If not specified, execution begins
	// immediately.
	WaitFile string
	// PostFile is the file to write when complete. If not specified, no
	// file is written.
	PostFile string

	// Waiter encapsulates waiting for files to exist.
	Waiter Waiter
	// Runner encapsulates running commands.
	Runner Runner
	// PostWriter encapsulates writing files when complete.
	PostWriter PostWriter
}

type PostWriter interface {
	// Write writes to the path when complete.
	Write(file string)
}

type Runner interface {
	Run(args ...string)
}

type Waiter interface {
	// Wait blocks until the specified file exists.
	Wait(file string)
}