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
90
91
92
93
94
95
96
|
// +build linux
package nsinit
import (
"github.com/dotcloud/docker/pkg/libcontainer"
"github.com/dotcloud/docker/pkg/libcontainer/network"
"github.com/dotcloud/docker/pkg/system"
"os"
"os/exec"
"syscall"
)
// Exec performes setup outside of a namespace so that a container can be
// executed. Exec is a high level function for working with container namespaces.
func (ns *linuxNs) Exec(container *libcontainer.Container, term Terminal, args []string) (int, error) {
var (
master *os.File
console string
err error
)
// create a pipe so that we can syncronize with the namespaced process and
// pass the veth name to the child
syncPipe, err := NewSyncPipe()
if err != nil {
return -1, err
}
if container.Tty {
master, console, err = system.CreateMasterAndConsole()
if err != nil {
return -1, err
}
term.SetMaster(master)
}
command := ns.commandFactory.Create(container, console, syncPipe.child, args)
if err := term.Attach(command); err != nil {
return -1, err
}
defer term.Close()
if err := command.Start(); err != nil {
return -1, err
}
if err := ns.stateWriter.WritePid(command.Process.Pid); err != nil {
command.Process.Kill()
return -1, err
}
defer ns.stateWriter.DeletePid()
// Do this before syncing with child so that no children
// can escape the cgroup
if err := ns.SetupCgroups(container, command.Process.Pid); err != nil {
command.Process.Kill()
return -1, err
}
if err := ns.InitializeNetworking(container, command.Process.Pid, syncPipe); err != nil {
command.Process.Kill()
return -1, err
}
// Sync with child
syncPipe.Close()
if err := command.Wait(); err != nil {
if _, ok := err.(*exec.ExitError); !ok {
return -1, err
}
}
return command.ProcessState.Sys().(syscall.WaitStatus).ExitStatus(), nil
}
func (ns *linuxNs) SetupCgroups(container *libcontainer.Container, nspid int) error {
if container.Cgroups != nil {
if err := container.Cgroups.Apply(nspid); err != nil {
return err
}
}
return nil
}
func (ns *linuxNs) InitializeNetworking(container *libcontainer.Container, nspid int, pipe *SyncPipe) error {
context := libcontainer.Context{}
for _, config := range container.Networks {
strategy, err := network.GetStrategy(config.Type)
if err != nil {
return err
}
if err := strategy.Create(config, nspid, context); err != nil {
return err
}
}
return pipe.SendToChild(context)
}
|
