-
Notifications
You must be signed in to change notification settings - Fork 89
/
cleanup_linux.go
202 lines (173 loc) · 5.71 KB
/
cleanup_linux.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
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
// Copyright (c) 2018-2021, Sylabs Inc. All rights reserved.
// This software is licensed under a 3-clause BSD license. Please consult the
// LICENSE.md file distributed with the sources of this project regarding your
// rights to use or distribute this software.
package singularity
import (
"context"
"fmt"
"os"
"path/filepath"
"runtime"
"strings"
"syscall"
"github.com/sylabs/singularity/v4/internal/pkg/instance"
fakerootConfig "github.com/sylabs/singularity/v4/internal/pkg/runtime/engine/fakeroot/config"
"github.com/sylabs/singularity/v4/internal/pkg/util/bin"
"github.com/sylabs/singularity/v4/internal/pkg/util/crypt"
"github.com/sylabs/singularity/v4/internal/pkg/util/priv"
"github.com/sylabs/singularity/v4/internal/pkg/util/starter"
"github.com/sylabs/singularity/v4/pkg/runtime/engine/config"
"github.com/sylabs/singularity/v4/pkg/sylog"
"github.com/sylabs/singularity/v4/pkg/util/capabilities"
)
// CleanupContainer is called from master after the MonitorContainer returns.
// It is responsible for ensuring that the container has been properly torn down.
//
// Additional privileges may be gained when running
// in suid flow. However, when a user namespace is requested and it is not
// a hybrid workflow (e.g. fakeroot), then there is no privileged saved uid
// and thus no additional privileges can be gained.
//
// For better understanding of runtime flow in general refer to
// https://github.com/opencontainers/runtime-spec/blob/master/runtime.md#lifecycle.
// CleanupContainer is performing step 8/9 here.
func (e *EngineOperations) CleanupContainer(ctx context.Context, _ error, _ syscall.WaitStatus) error {
// firstly stop all fuse drivers before any image removal
// by image driver interruption or image cleanup for hybrid
// fakeroot workflow
e.stopFuseDrivers()
if e.EngineConfig.GetImageFuse() {
// Lazy unmount so any underlay mount points don't block umount call against rootfs,
// which must be unmounted from master to proceed with the host cleanup.
// Everything is tidied up as the container mount namespace disappears.
if err := umount(true); err != nil {
sylog.Errorf("%s", err)
}
}
if tempDir := e.EngineConfig.GetDeleteTempDir(); tempDir != "" && !e.EngineConfig.GetImageFuse() {
sylog.Verbosef("Removing image tempDir %s", tempDir)
sylog.Infof("Cleaning up image...")
var err error
if e.EngineConfig.GetFakeroot() && os.Getuid() != 0 {
// this is required when we are using SUID workflow
// because master process is not in the fakeroot
// context and can get permission denied error during
// image removal, so we execute "rm -rf /tmp/image" via
// the fakeroot engine
err = fakerootCleanup(tempDir)
} else {
err = os.RemoveAll(tempDir)
}
if err != nil {
sylog.Errorf("failed to delete container image tempDir %s: %s", tempDir, err)
}
}
if networkSetup != nil {
net := e.EngineConfig.GetNetwork()
privileged := false
// If a CNI configuration was allowed as non-root (or fakeroot)
if net != "none" && os.Geteuid() != 0 {
priv.Escalate()
privileged = true
}
sylog.Debugf("Cleaning up CNI network config %s", net)
if err := networkSetup.DelNetworks(ctx); err != nil {
sylog.Errorf("could not delete networks: %v", err)
}
if privileged {
priv.Drop()
}
}
if cgroupsManager != nil {
if err := cgroupsManager.Destroy(); err != nil {
sylog.Warningf("failed to remove cgroup configuration: %v", err)
}
}
if cryptDev != "" {
if err := cleanupCrypt(cryptDev); err != nil {
sylog.Errorf("could not cleanup crypt: %v", err)
}
}
if e.EngineConfig.GetInstance() {
file, err := instance.Get(e.CommonConfig.ContainerID, instance.SingSubDir)
if err != nil {
return err
}
return file.Delete()
}
return nil
}
func umount(lazy bool) (err error) {
var oldEffective uint64
caps := uint64(0)
caps |= uint64(1 << capabilities.Map["CAP_SYS_ADMIN"].Value)
umountFlags := 0
if lazy {
umountFlags = syscall.MNT_DETACH
}
runtime.LockOSThread()
defer runtime.UnlockOSThread()
oldEffective, err = capabilities.SetProcessEffective(caps)
if err != nil {
return err
}
defer func() {
_, e := capabilities.SetProcessEffective(oldEffective)
if err == nil {
err = e
}
}()
for i := len(umountPoints) - 1; i >= 0; i-- {
p := umountPoints[i]
sylog.Debugf("Umount %s", p)
retries := 0
retry:
err = syscall.Unmount(p, umountFlags)
// ignore EINVAL meaning it's not a mount point
//nolint:forcetypeassert
if err != nil && err.(syscall.Errno) != syscall.EINVAL {
// when rootfs mount point is a sandbox, the unmount
// fail more often with EBUSY, but it's just a matter of
// time before resources are released by the kernel so we
// retry until the unmount operation succeed (retries 10 times)
//nolint:forcetypeassert
if err.(syscall.Errno) == syscall.EBUSY && retries < 10 {
retries++
goto retry
}
return fmt.Errorf("while unmounting %s directory: %s", p, err)
}
}
return err
}
func cleanupCrypt(path string) error {
// Strict umount to be sure crypt device not in use
if err := umount(false); err != nil {
return err
}
devName := filepath.Base(path)
cryptDev := &crypt.Device{}
if err := cryptDev.CloseCryptDevice(devName); err != nil {
return fmt.Errorf("unable to delete crypt device: %s", devName)
}
return nil
}
func fakerootCleanup(path string) error {
rm, err := bin.FindBin("rm")
if err != nil {
return err
}
command := []string{rm, "-rf", path}
sylog.Debugf("Calling fakeroot engine to execute %q", strings.Join(command, " "))
cfg := &config.Common{
EngineName: fakerootConfig.Name,
ContainerID: "fakeroot",
EngineConfig: &fakerootConfig.EngineConfig{Args: command},
}
return starter.Run(
"Singularity fakeroot",
cfg,
starter.UseSuid(true),
)
}