builder/amazon/chroot: provision within the chroot

This commit is contained in:
Mitchell Hashimoto 2013-07-30 14:44:03 -07:00
parent 778657e995
commit 9f2399516a
3 changed files with 130 additions and 0 deletions

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package chroot
import (
"github.com/mitchellh/packer/packer"
"io"
"log"
"os"
"os/exec"
"path/filepath"
"syscall"
)
// Communicator is a special communicator that works by executing
// commands locally but within a chroot.
type Communicator struct {
Chroot string
}
func (c *Communicator) Start(cmd *packer.RemoteCmd) error {
chrootCmdPath, err := exec.LookPath("chroot")
if err != nil {
return err
}
localCmd := exec.Command(chrootCmdPath, c.Chroot, "/bin/sh", "-c", cmd.Command)
localCmd.Stdin = cmd.Stdin
localCmd.Stdout = cmd.Stdout
localCmd.Stderr = cmd.Stderr
log.Printf("Executing: %s %#v", localCmd.Path, localCmd.Args)
if err := localCmd.Start(); err != nil {
return err
}
go func() {
exitStatus := 0
if err := localCmd.Wait(); err != nil {
if exitErr, ok := err.(*exec.ExitError); ok {
exitStatus = 1
// There is no process-independent way to get the REAL
// exit status so we just try to go deeper.
if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
exitStatus = status.ExitStatus()
}
}
}
cmd.SetExited(exitStatus)
}()
return nil
}
func (c *Communicator) Upload(dst string, r io.Reader) error {
dst = filepath.Join(c.Chroot, dst)
f, err := os.Open(dst)
if err != nil {
return err
}
defer f.Close()
if _, err := io.Copy(f, r); err != nil {
return err
}
return nil
}
func (c *Communicator) Download(src string, w io.Writer) error {
src = filepath.Join(c.Chroot, src)
f, err := os.Open(src)
if err != nil {
return err
}
defer f.Close()
if _, err := io.Copy(w, f); err != nil {
return err
}
return nil
}

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package chroot
import (
"github.com/mitchellh/packer/packer"
"testing"
)
func TestCommunicator_ImplementsCommunicator(t *testing.T) {
var raw interface{}
raw = &Communicator{}
if _, ok := raw.(packer.Communicator); !ok {
t.Fatalf("Communicator should be a communicator")
}
}

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package chroot
import (
"github.com/mitchellh/multistep"
"github.com/mitchellh/packer/packer"
"log"
)
// StepChrootProvision provisions the instance within a chroot.
type StepChrootProvision struct {
mounts []string
}
func (s *StepChrootProvision) Run(state map[string]interface{}) multistep.StepAction {
hook := state["hook"].(packer.Hook)
mountPath := state["mount_path"].(string)
ui := state["ui"].(packer.Ui)
// Create our communicator
comm := &Communicator{
Chroot: mountPath,
}
// Provision
log.Println("Running the provision hook")
if err := hook.Run(packer.HookProvision, ui, comm, nil); err != nil {
state["error"] = err
return multistep.ActionHalt
}
return multistep.ActionContinue
}
func (s *StepChrootProvision) Cleanup(state map[string]interface{}) {}