error.go

package vagrantutil

import (
	"errors"
	"os"
	"strings"
)

// List of errors ignored by Destroy / Status methods:
const (
	errNotCreated    = "A Vagrant environment or target machine is required to run this"
	errRubyNotExists = "No such file or directory - getcwd (Errno::ENOENT)"
)

func isNotCreated(err error) bool {
	return os.IsNotExist(err) || strings.Contains(err.Error(), errNotCreated) ||
		strings.Contains(err.Error(), errRubyNotExists)
}

// The following errors are returned by the Wait function:
var (
	ErrBoxAlreadyExists  = errors.New("box already exists")
	ErrBoxInvalidVersion = errors.New("invalid box version")
	ErrBoxNotAvailable   = errors.New("box is not available")
	ErrBoxDownload       = errors.New("unable to download the box")
	ErrVirtualBox        = errors.New("VirtualBox is missing or not operational")
)

var defaultWaiter Waiter

// Waiter is used to consume output channel from a Vagrant command, parsing
// each line looking for an error when command execution fails.
type Waiter struct {
	// OutputFunc, when non-nil, is called each time a Wait method receives
	// a line of output from command channel.
	OutputFunc func(string)
}

// Wait is a convenience method that consumes Vagrant output looking
// for well-known errors.
//
// It returns an error variable for any known error condition, which makes it
// easier for the caller to recover from failure.
//
// If OutputFunc is non-nil, it's called on each line of output received
// from the out channel.
func (w *Waiter) Wait(out <-chan *CommandOutput, err error) error {
	var e error
	for o := range out {
		if w.OutputFunc != nil {
			w.OutputFunc(o.Line)
		}
		for s, err := range errMapping {
			if strings.Contains(o.Line, s) {
				e = nonil(e, err)
			}
		}
		e = nonil(e, o.Error)
	}
	return nonil(e, err)
}

// Wait is a convenience function that consumes Vagrant output looking
// for well-known errors.
func Wait(out <-chan *CommandOutput, err error) error {
	return defaultWaiter.Wait(out, err)
}

var errMapping = map[string]error{
	"The box you're attempting to add already exists.":               ErrBoxAlreadyExists,
	"Gem::Requirement::BadRequirementError":                          ErrBoxInvalidVersion,
	"could not be accessed in the remote catalog.":                   ErrBoxNotAvailable,
	"An error occurred while downloading the remote file.":           ErrBoxDownload,
	"VirtualBox is complaining that the kernel module is not loaded": ErrVirtualBox,
}

func nonil(err ...error) error {
	for _, e := range err {
		if e != nil {
			return e
		}
	}
	return nil
}