forked from containers/build
/
chroot-child.go
89 lines (79 loc) · 2.33 KB
/
chroot-child.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
// Copyright 2016 The appc Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package chroot
import (
"fmt"
"os"
"os/exec"
"runtime"
"strings"
"syscall"
"github.com/spf13/cobra"
)
func init() {
cmdACBuildChroot.PersistentFlags().StringVar(&flagCmd, "cmd", "", "The command to run")
cmdACBuildChroot.PersistentFlags().StringSliceVar(&flagArgs, "args", nil, "arguments for the command")
cmdACBuildChroot.PersistentFlags().StringSliceVar(&flagEnv, "env", nil, "environment for the command")
cmdACBuildChroot.PersistentFlags().StringVar(&flagChroot, "chroot", "", "dir to chroot into")
cmdACBuildChroot.PersistentFlags().StringVar(&flagWorkingDir, "working-dir", "", "working directory for the command")
}
var (
flagCmd string
flagArgs []string
flagEnv []string
flagChroot string
flagWorkingDir string
cmdACBuildChroot = &cobra.Command{
Use: "",
Run: runChroot,
}
)
func stderr(format string, a ...interface{}) {
out := fmt.Sprintf(format, a...)
fmt.Fprintln(os.Stderr, strings.TrimSuffix(out, "\n"))
}
func errAndExit(format string, a ...interface{}) {
stderr(format, a...)
os.Exit(1)
}
func runChroot(cmd *cobra.Command, args []string) {
runtime.LockOSThread()
err := syscall.Chroot(flagChroot)
if err != nil {
errAndExit("couldn't chroot: %v", err)
}
err = os.Chdir("/")
if err != nil {
errAndExit("couldn't cd: %v", err)
}
if flagWorkingDir != "" {
err = os.Chdir(flagWorkingDir)
if err != nil {
errAndExit("couldn't cd: %v", err)
}
}
execCmd := exec.Command(flagCmd, flagArgs...)
execCmd.Env = flagEnv
execCmd.Stdin = os.Stdin
execCmd.Stdout = os.Stdout
execCmd.Stderr = os.Stderr
err = execCmd.Run()
if err != nil {
if exitErr, ok := err.(*exec.ExitError); ok {
code := exitErr.Sys().(syscall.WaitStatus).ExitStatus()
os.Exit(code)
}
errAndExit("%v", err)
}
}