File: state_linux.go

package info (click to toggle)
runc 1.0.0~rc6%2Bdfsg1-3
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 1,972 kB
  • sloc: sh: 1,386; ansic: 946; makefile: 117
file content (251 lines) | stat: -rw-r--r-- 5,273 bytes parent folder | download | duplicates (2)
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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
// +build linux

package libcontainer

import (
	"fmt"
	"os"
	"path/filepath"

	"github.com/opencontainers/runc/libcontainer/configs"

	"github.com/sirupsen/logrus"
	"golang.org/x/sys/unix"
)

func newStateTransitionError(from, to containerState) error {
	return &stateTransitionError{
		From: from.status().String(),
		To:   to.status().String(),
	}
}

// stateTransitionError is returned when an invalid state transition happens from one
// state to another.
type stateTransitionError struct {
	From string
	To   string
}

func (s *stateTransitionError) Error() string {
	return fmt.Sprintf("invalid state transition from %s to %s", s.From, s.To)
}

type containerState interface {
	transition(containerState) error
	destroy() error
	status() Status
}

func destroy(c *linuxContainer) error {
	if !c.config.Namespaces.Contains(configs.NEWPID) {
		if err := signalAllProcesses(c.cgroupManager, unix.SIGKILL); err != nil {
			logrus.Warn(err)
		}
	}
	err := c.cgroupManager.Destroy()
	if c.intelRdtManager != nil {
		if ierr := c.intelRdtManager.Destroy(); err == nil {
			err = ierr
		}
	}
	if rerr := os.RemoveAll(c.root); err == nil {
		err = rerr
	}
	c.initProcess = nil
	if herr := runPoststopHooks(c); err == nil {
		err = herr
	}
	c.state = &stoppedState{c: c}
	return err
}

func runPoststopHooks(c *linuxContainer) error {
	if c.config.Hooks != nil {
		s, err := c.currentOCIState()
		if err != nil {
			return err
		}
		for _, hook := range c.config.Hooks.Poststop {
			if err := hook.Run(s); err != nil {
				return err
			}
		}
	}
	return nil
}

// stoppedState represents a container is a stopped/destroyed state.
type stoppedState struct {
	c *linuxContainer
}

func (b *stoppedState) status() Status {
	return Stopped
}

func (b *stoppedState) transition(s containerState) error {
	switch s.(type) {
	case *runningState, *restoredState:
		b.c.state = s
		return nil
	case *stoppedState:
		return nil
	}
	return newStateTransitionError(b, s)
}

func (b *stoppedState) destroy() error {
	return destroy(b.c)
}

// runningState represents a container that is currently running.
type runningState struct {
	c *linuxContainer
}

func (r *runningState) status() Status {
	return Running
}

func (r *runningState) transition(s containerState) error {
	switch s.(type) {
	case *stoppedState:
		t, err := r.c.runType()
		if err != nil {
			return err
		}
		if t == Running {
			return newGenericError(fmt.Errorf("container still running"), ContainerNotStopped)
		}
		r.c.state = s
		return nil
	case *pausedState:
		r.c.state = s
		return nil
	case *runningState:
		return nil
	}
	return newStateTransitionError(r, s)
}

func (r *runningState) destroy() error {
	t, err := r.c.runType()
	if err != nil {
		return err
	}
	if t == Running {
		return newGenericError(fmt.Errorf("container is not destroyed"), ContainerNotStopped)
	}
	return destroy(r.c)
}

type createdState struct {
	c *linuxContainer
}

func (i *createdState) status() Status {
	return Created
}

func (i *createdState) transition(s containerState) error {
	switch s.(type) {
	case *runningState, *pausedState, *stoppedState:
		i.c.state = s
		return nil
	case *createdState:
		return nil
	}
	return newStateTransitionError(i, s)
}

func (i *createdState) destroy() error {
	i.c.initProcess.signal(unix.SIGKILL)
	return destroy(i.c)
}

// pausedState represents a container that is currently pause.  It cannot be destroyed in a
// paused state and must transition back to running first.
type pausedState struct {
	c *linuxContainer
}

func (p *pausedState) status() Status {
	return Paused
}

func (p *pausedState) transition(s containerState) error {
	switch s.(type) {
	case *runningState, *stoppedState:
		p.c.state = s
		return nil
	case *pausedState:
		return nil
	}
	return newStateTransitionError(p, s)
}

func (p *pausedState) destroy() error {
	t, err := p.c.runType()
	if err != nil {
		return err
	}
	if t != Running && t != Created {
		if err := p.c.cgroupManager.Freeze(configs.Thawed); err != nil {
			return err
		}
		return destroy(p.c)
	}
	return newGenericError(fmt.Errorf("container is paused"), ContainerPaused)
}

// restoredState is the same as the running state but also has associated checkpoint
// information that maybe need destroyed when the container is stopped and destroy is called.
type restoredState struct {
	imageDir string
	c        *linuxContainer
}

func (r *restoredState) status() Status {
	return Running
}

func (r *restoredState) transition(s containerState) error {
	switch s.(type) {
	case *stoppedState, *runningState:
		return nil
	}
	return newStateTransitionError(r, s)
}

func (r *restoredState) destroy() error {
	if _, err := os.Stat(filepath.Join(r.c.root, "checkpoint")); err != nil {
		if !os.IsNotExist(err) {
			return err
		}
	}
	return destroy(r.c)
}

// loadedState is used whenever a container is restored, loaded, or setting additional
// processes inside and it should not be destroyed when it is exiting.
type loadedState struct {
	c *linuxContainer
	s Status
}

func (n *loadedState) status() Status {
	return n.s
}

func (n *loadedState) transition(s containerState) error {
	n.c.state = s
	return nil
}

func (n *loadedState) destroy() error {
	if err := n.c.refreshState(); err != nil {
		return err
	}
	return n.c.state.destroy()
}