cri-o/utils/utils.go
Samuel Ortiz 9a4a1092fe
conmon: Return the exit status code
waitpid fills its second argument with a value that
contains the process exit code in the 8 least significant
bits. Instead of returning the complete value and then
convert it from ocid, return the exit status directly
by using WEXITSTATUS from conmon.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2017-01-14 02:00:45 +01:00

127 lines
3.1 KiB
Go

package utils
import (
"bytes"
"fmt"
"io"
"os"
"os/exec"
"path/filepath"
"strings"
"syscall"
"github.com/Sirupsen/logrus"
)
// ExecCmd executes a command with args and returns its output as a string along
// with an error, if any
func ExecCmd(name string, args ...string) (string, error) {
cmd := exec.Command(name, args...)
var stdout bytes.Buffer
var stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
err := cmd.Run()
if err != nil {
return "", fmt.Errorf("`%v %v` failed: %v (%v)", name, strings.Join(args, " "), stderr.String(), err)
}
return stdout.String(), nil
}
// ExecCmdWithStdStreams execute a command with the specified standard streams.
func ExecCmdWithStdStreams(stdin io.Reader, stdout, stderr io.Writer, name string, args ...string) error {
cmd := exec.Command(name, args...)
cmd.Stdin = stdin
cmd.Stdout = stdout
cmd.Stderr = stderr
err := cmd.Run()
if err != nil {
return fmt.Errorf("`%v %v` failed: %v", name, strings.Join(args, " "), err)
}
return nil
}
// Prctl is a way to make the prctl linux syscall
func Prctl(option int, arg2, arg3, arg4, arg5 uintptr) (err error) {
_, _, e1 := syscall.Syscall6(syscall.SYS_PRCTL, uintptr(option), arg2, arg3, arg4, arg5, 0)
if e1 != 0 {
err = e1
}
return
}
// CreateFakeRootfs creates a fake rootfs for test.
func CreateFakeRootfs(dir string, image string) error {
if len(image) <= 9 || image[:9] != "docker://" {
return fmt.Errorf("CreateFakeRootfs only support docker images currently")
}
rootfs := filepath.Join(dir, "rootfs")
if err := os.MkdirAll(rootfs, 0755); err != nil {
return err
}
// docker export $(docker create image[9:]) | tar -C rootfs -xf -
return dockerExport(image[9:], rootfs)
}
// CreateInfraRootfs creates a rootfs similar to CreateFakeRootfs, but only
// copies a single binary from the host into the rootfs. This is all done
// without Docker, and is only used currently for the pause container which is
// required for all sandboxes.
func CreateInfraRootfs(dir string, src string) error {
rootfs := filepath.Join(dir, "rootfs")
if err := os.MkdirAll(rootfs, 0755); err != nil {
return err
}
dest := filepath.Join(rootfs, filepath.Base(src))
logrus.Debugf("copying infra rootfs binary: %v -> %v", src, dest)
in, err := os.OpenFile(src, os.O_RDONLY, 0755)
if err != nil {
return err
}
defer in.Close()
out, err := os.OpenFile(dest, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0755)
if err != nil {
return err
}
defer out.Close()
if _, err := io.Copy(out, in); err != nil {
return err
}
return out.Sync()
}
func dockerExport(image string, rootfs string) error {
out, err := ExecCmd("docker", "create", image)
if err != nil {
return err
}
container := out[:strings.Index(out, "\n")]
cmd := fmt.Sprintf("docker export %s | tar -C %s -xf -", container, rootfs)
if _, err := ExecCmd("/bin/bash", "-c", cmd); err != nil {
err1 := dockerRemove(container)
if err1 == nil {
return err
}
return fmt.Errorf("%v; %v", err, err1)
}
return dockerRemove(container)
}
func dockerRemove(container string) error {
_, err := ExecCmd("docker", "rm", container)
return err
}