packer-cn/provisioner/salt/provisioner.go

// This package implements a provisioner for Packer that executes a
// saltstack highstate within the remote machine
package salt

import (
	"fmt"
	"github.com/mitchellh/iochan"
	"github.com/mitchellh/mapstructure"
	"github.com/mitchellh/packer/packer"
	"io"
	"log"
	"sort"
	"strings"
)

var Ui packer.Ui

type config struct {
	// If true, skips installing Salt. Defaults to false.
	SkipInstall bool `mapstructure:"skip_install"`
}

type Provisioner struct {
	config config
}

func (p *Provisioner) Prepare(raws ...interface{}) error {
	var md mapstructure.Metadata
	decoderConfig := &mapstructure.DecoderConfig{
		Metadata: &md,
		Result:   &p.config,
	}

	decoder, err := mapstructure.NewDecoder(decoderConfig)
	if err != nil {
		return err
	}

	for _, raw := range raws {
		err := decoder.Decode(raw)
		if err != nil {
			return err
		}
	}

	// Accumulate any errors
	errs := make([]error, 0)

	// Unused keys are errors
	if len(md.Unused) > 0 {
		sort.Strings(md.Unused)
		for _, unused := range md.Unused {
			if unused != "type" && !strings.HasPrefix(unused, "packer_") {
				errs = append(
					errs, fmt.Errorf("Unknown configuration key: %s", unused))
			}
		}
	}

	if len(errs) > 0 {
		return &packer.MultiError{errs}
	}

	return nil
}

func InstallSalt(comm packer.Communicator) (err error) {
	Ui.Say("Installing Salt")
	cmd := "wget -O - http://bootstrap.saltstack.org | sudo sh"
	if err = executeCommand(cmd, comm); err != nil {
		return fmt.Errorf("Unable to install Salt: %d", err)
	}

	return nil
}

func (p *Provisioner) Provision(ui packer.Ui, comm packer.Communicator) error {
	var err error
	Ui = ui

	if !p.config.SkipInstall {
		if err = InstallSalt(comm); err != nil {
			return fmt.Errorf("Error installing Salt: %s", err)
		}
	}

	return nil
}

func executeCommand(command string, comm packer.Communicator) (err error) {
	// Setup the remote command
	stdout_r, stdout_w := io.Pipe()
	stderr_r, stderr_w := io.Pipe()

	var cmd packer.RemoteCmd
	cmd.Command = command
	cmd.Stdout = stdout_w
	cmd.Stderr = stderr_w

	log.Printf("Executing command: %s", cmd.Command)
	err = comm.Start(&cmd)
	if err != nil {
		return fmt.Errorf("Failed executing command: %s", err)
	}

	exitChan := make(chan int, 1)
	stdoutChan := iochan.DelimReader(stdout_r, '\n')
	stderrChan := iochan.DelimReader(stderr_r, '\n')

	go func() {
		defer stdout_w.Close()
		defer stderr_w.Close()

		cmd.Wait()
		exitChan <- cmd.ExitStatus
	}()

OutputLoop:
	for {
		select {
		case output := <-stderrChan:
			Ui.Message(strings.TrimSpace(output))
		case output := <-stdoutChan:
			Ui.Message(strings.TrimSpace(output))
		case exitStatus := <-exitChan:
			log.Printf("Chef Solo provisioner exited with status %d", exitStatus)

			if exitStatus != 0 {
				return fmt.Errorf("Command exited with non-zero exit status: %d", exitStatus)
			}

			break OutputLoop
		}
	}

	// Make sure we finish off stdout/stderr because we may have gotten
	// a message from the exit channel first.
	for output := range stdoutChan {
		Ui.Message(output)
	}

	for output := range stderrChan {
		Ui.Message(output)
	}

	return nil
}