packer-cn/builder/lxc/communicator.go

180 lines
4.4 KiB
Go

package lxc
import (
"fmt"
"io"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
"strings"
"syscall"
"github.com/hashicorp/packer/packer"
)
type LxcAttachCommunicator struct {
RootFs string
ContainerName string
AttachOptions []string
CmdWrapper CommandWrapper
}
func (c *LxcAttachCommunicator) Start(cmd *packer.RemoteCmd) error {
localCmd, err := c.Execute(cmd.Command)
if err != nil {
return err
}
localCmd.Stdin = cmd.Stdin
localCmd.Stdout = cmd.Stdout
localCmd.Stderr = cmd.Stderr
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()
}
}
}
log.Printf(
"lxc-attach execution exited with '%d': '%s'",
exitStatus, cmd.Command)
cmd.SetExited(exitStatus)
}()
return nil
}
func (c *LxcAttachCommunicator) Upload(dst string, r io.Reader, fi *os.FileInfo) error {
log.Printf("Uploading to rootfs: %s", dst)
tf, err := ioutil.TempFile("", "packer-lxc-attach")
if err != nil {
return fmt.Errorf("Error uploading file to rootfs: %s", err)
}
defer os.Remove(tf.Name())
io.Copy(tf, r)
attachCommand := []string{"cat", "%s", " | ", "lxc-attach"}
attachCommand = append(attachCommand, c.AttachOptions...)
attachCommand = append(attachCommand, []string{"--name", "%s", "--", "/bin/sh -c \"/bin/cat > %s\""}...)
cpCmd, err := c.CmdWrapper(fmt.Sprintf(strings.Join(attachCommand, " "), tf.Name(), c.ContainerName, dst))
if err != nil {
return err
}
if fi != nil {
tfDir := filepath.Dir(tf.Name())
// rename tempfile to match original file name. This makes sure that if file is being
// moved into a directory, the filename is preserved instead of a temp name.
adjustedTempName := filepath.Join(tfDir, (*fi).Name())
mvCmd, err := c.CmdWrapper(fmt.Sprintf("mv %s %s", tf.Name(), adjustedTempName))
if err != nil {
return err
}
defer os.Remove(adjustedTempName)
ShellCommand(mvCmd).Run()
// change cpCmd to use new file name as source
cpCmd, err = c.CmdWrapper(fmt.Sprintf(strings.Join(attachCommand, " "), adjustedTempName, c.ContainerName, dst))
if err != nil {
return err
}
}
log.Printf("Running copy command: %s", dst)
return ShellCommand(cpCmd).Run()
}
func (c *LxcAttachCommunicator) UploadDir(dst string, src string, exclude []string) error {
// TODO: remove any file copied if it appears in `exclude`
dest := filepath.Join(c.RootFs, dst)
log.Printf("Uploading directory '%s' to rootfs '%s'", src, dest)
cpCmd, err := c.CmdWrapper(fmt.Sprintf("cp -R %s/. %s", src, dest))
if err != nil {
return err
}
return ShellCommand(cpCmd).Run()
}
func (c *LxcAttachCommunicator) Download(src string, w io.Writer) error {
src = filepath.Join(c.RootFs, src)
log.Printf("Downloading from rootfs dir: %s", 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
}
func (c *LxcAttachCommunicator) DownloadDir(src string, dst string, exclude []string) error {
return fmt.Errorf("DownloadDir is not implemented for lxc")
}
func (c *LxcAttachCommunicator) Execute(commandString string) (*exec.Cmd, error) {
log.Printf("Executing with lxc-attach in container: %s %s %s", c.ContainerName, c.RootFs, commandString)
attachCommand := []string{"lxc-attach"}
attachCommand = append(attachCommand, c.AttachOptions...)
attachCommand = append(attachCommand, []string{"--name", "%s", "--", "/bin/sh -c \"%s\""}...)
command, err := c.CmdWrapper(
fmt.Sprintf(strings.Join(attachCommand, " "), c.ContainerName, commandString))
if err != nil {
return nil, err
}
localCmd := ShellCommand(command)
log.Printf("Executing lxc-attach: %s %#v", localCmd.Path, localCmd.Args)
return localCmd, nil
}
func (c *LxcAttachCommunicator) CheckInit() (string, error) {
log.Printf("Debug runlevel exec")
localCmd, err := c.Execute("/sbin/runlevel")
if err != nil {
return "", err
}
pr, _ := localCmd.StdoutPipe()
if err = localCmd.Start(); err != nil {
return "", err
}
output, err := ioutil.ReadAll(pr)
if err != nil {
return "", err
}
err = localCmd.Wait()
if err != nil {
return "", err
}
return strings.TrimSpace(string(output)), nil
}