aboutsummaryrefslogtreecommitdiff
path: root/libpod/container.go
blob: 9b48d2ca166e952cd1c40e9deeb6fec6a72b5f81 (plain)
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
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
package libpod

import (
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"sync"
	"time"

	"github.com/containers/storage"
	"github.com/containers/storage/pkg/archive"
	"github.com/docker/docker/pkg/stringid"
	"github.com/docker/docker/pkg/term"
	spec "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/pkg/errors"
	crioAnnotations "github.com/projectatomic/libpod/pkg/annotations"
	"github.com/sirupsen/logrus"
	"github.com/ulule/deepcopier"
	"k8s.io/client-go/tools/remotecommand"
)

// ContainerState represents the current state of a container
type ContainerState int

const (
	// ContainerStateUnknown indicates that the container is in an error
	// state where information about it cannot be retrieved
	ContainerStateUnknown ContainerState = iota
	// ContainerStateConfigured indicates that the container has had its
	// storage configured but it has not been created in the OCI runtime
	ContainerStateConfigured ContainerState = iota
	// ContainerStateCreated indicates the container has been created in
	// the OCI runtime but not started
	ContainerStateCreated ContainerState = iota
	// ContainerStateRunning indicates the container is currently executing
	ContainerStateRunning ContainerState = iota
	// ContainerStateStopped indicates that the container was running but has
	// exited
	ContainerStateStopped ContainerState = iota
	// ContainerStatePaused indicates that the container has been paused
	ContainerStatePaused ContainerState = iota
)

// Container is a single OCI container
type Container struct {
	config *containerConfig

	pod         *Pod
	runningSpec *spec.Spec

	state *containerRuntimeInfo

	// TODO move to storage.Locker from sync.Mutex
	valid   bool
	lock    sync.Mutex
	runtime *Runtime
}

// containerState contains the current state of the container
// It is stored on disk in a tmpfs and recreated on reboot
type containerRuntimeInfo struct {
	// The current state of the running container
	State ContainerState `json:"state"`
	// The path to the JSON OCI runtime spec for this container
	ConfigPath string `json:"configPath,omitempty"`
	// RunDir is a per-boot directory for container content
	RunDir string `json:"runDir,omitempty"`
	// Mounted indicates whether the container's storage has been mounted
	// for use
	Mounted bool `json:"mounted,omitempty"`
	// MountPoint contains the path to the container's mounted storage
	Mountpoint string `json:"mountPoint,omitempty"`
	// StartedTime is the time the container was started
	StartedTime time.Time `json:"startedTime,omitempty"`
	// FinishedTime is the time the container finished executing
	FinishedTime time.Time `json:"finishedTime,omitempty"`
	// ExitCode is the exit code returned when the container stopped
	ExitCode int32 `json:"exitCode,omitempty"`
	// OOMKilled indicates that the container was killed as it ran out of
	// memory
	OOMKilled bool `json:"oomKilled,omitempty"`
	// PID is the PID of a running container
	PID int `json:"pid,omitempty"`

	// TODO: Save information about image used in container if one is used
}

// containerConfig contains all information that was used to create the
// container. It may not be changed once created.
// It is stored, read-only, on disk
type containerConfig struct {
	Spec *spec.Spec `json:"spec"`
	ID   string     `json:"id"`
	Name string     `json:"name"`
	// Information on the image used for the root filesystem
	RootfsImageID   string `json:"rootfsImageID,omitempty"`
	RootfsImageName string `json:"rootfsImageName,omitempty"`
	UseImageConfig  bool   `json:"useImageConfig"`
	// SELinux mount label for root filesystem
	MountLabel string `json:"MountLabel,omitempty"`
	// Static directory for container content that will persist across
	// reboot
	StaticDir string `json:"staticDir"`
	// Whether to keep container STDIN open
	Stdin bool
	// Pod the container belongs to
	Pod string `json:"pod,omitempty"`
	// Labels is a set of key-value pairs providing additional information
	// about a container
	Labels map[string]string `json:"labels,omitempty"`
	// StopSignal is the signal that will be used to stop the container
	StopSignal uint `json:"stopSignal,omitempty"`
	// Shared namespaces with container
	SharedNamespaceCtr *string           `json:"shareNamespacesWith,omitempty"`
	SharedNamespaceMap map[string]string `json:"sharedNamespaces"`
	// Time container was created
	CreatedTime time.Time `json:"createdTime"`

	// TODO save log location here and pass into OCI code
	// TODO allow overriding of log path
}

// ID returns the container's ID
func (c *Container) ID() string {
	return c.config.ID
}

// Name returns the container's name
func (c *Container) Name() string {
	return c.config.Name
}

// Spec returns the container's OCI runtime spec
// The spec returned is the one used to create the container. The running
// spec may differ slightly as mounts are added based on the image
func (c *Container) Spec() *spec.Spec {
	returnSpec := new(spec.Spec)
	deepcopier.Copy(c.config.Spec).To(returnSpec)

	return returnSpec
}

// Labels returns the container's labels
func (c *Container) Labels() map[string]string {
	labels := make(map[string]string)
	for key, value := range c.config.Labels {
		labels[key] = value
	}

	return labels
}

// LogPath returns the path to the container's log file
// This file will only be present after Init() is called to create the container
// in runc
func (c *Container) LogPath() string {
	// TODO store this in state and allow overriding
	return c.logPath()
}

// State returns the current state of the container
func (c *Container) State() (ContainerState, error) {
	c.lock.Lock()
	defer c.lock.Unlock()

	if err := c.syncContainer(); err != nil {
		return ContainerStateUnknown, err
	}

	return c.state.State, nil
}

// PID returns the PID of the container
// An error is returned if the container is not running
func (c *Container) PID() (int, error) {
	c.lock.Lock()
	defer c.lock.Unlock()

	if err := c.syncContainer(); err != nil {
		return -1, err
	}

	return c.state.PID, nil
}

// The path to the container's root filesystem - where the OCI spec will be
// placed, amongst other things
func (c *Container) bundlePath() string {
	return c.state.RunDir
}

// The path to the container's logs file
func (c *Container) logPath() string {
	return filepath.Join(c.config.StaticDir, "ctr.log")
}

// Retrieves the path of the container's attach socket
func (c *Container) attachSocketPath() string {
	return filepath.Join(c.runtime.ociRuntime.socketsDir, c.ID(), "attach")
}

// Sync this container with on-disk state and runc status
// Should only be called with container lock held
func (c *Container) syncContainer() error {
	if err := c.runtime.state.UpdateContainer(c); err != nil {
		return err
	}

	// If runc knows about the container, update its status in runc
	// And then save back to disk
	if (c.state.State != ContainerStateUnknown) &&
		(c.state.State != ContainerStateConfigured) {
		if err := c.runtime.ociRuntime.updateContainerStatus(c); err != nil {
			return err
		}
		if err := c.runtime.state.SaveContainer(c); err != nil {
			return err
		}
	}

	if !c.valid {
		return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
	}

	return nil
}

// Make a new container
func newContainer(rspec *spec.Spec) (*Container, error) {
	if rspec == nil {
		return nil, errors.Wrapf(ErrInvalidArg, "must provide a valid runtime spec to create container")
	}

	ctr := new(Container)
	ctr.config = new(containerConfig)
	ctr.state = new(containerRuntimeInfo)

	ctr.config.ID = stringid.GenerateNonCryptoID()
	ctr.config.Name = ctr.config.ID // TODO generate unique human-readable names

	ctr.config.Spec = new(spec.Spec)
	deepcopier.Copy(rspec).To(ctr.config.Spec)

	ctr.config.CreatedTime = time.Now()

	return ctr, nil
}

// Create container root filesystem for use
func (c *Container) setupStorage() error {
	if !c.valid {
		return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
	}

	if c.state.State != ContainerStateConfigured {
		return errors.Wrapf(ErrCtrStateInvalid, "container %s must be in Configured state to have storage set up", c.ID())
	}

	// Need both an image ID and image name, plus a bool telling us whether to use the image configuration
	if c.config.RootfsImageID == "" || c.config.RootfsImageName == "" {
		return errors.Wrapf(ErrInvalidArg, "must provide image ID and image name to use an image")
	}

	containerInfo, err := c.runtime.storageService.CreateContainerStorage(c.runtime.imageContext, c.config.RootfsImageName, c.config.RootfsImageID, c.config.Name, c.config.ID, c.config.MountLabel)
	if err != nil {
		return errors.Wrapf(err, "error creating container storage")
	}

	c.config.StaticDir = containerInfo.Dir
	c.state.RunDir = containerInfo.RunDir

	return nil
}

// Tear down a container's storage prior to removal
func (c *Container) teardownStorage() error {
	if !c.valid {
		return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
	}

	if c.state.State == ContainerStateRunning || c.state.State == ContainerStatePaused {
		return errors.Wrapf(ErrCtrStateInvalid, "cannot remove storage for container %s as it is running or paused", c.ID())
	}

	if c.state.Mounted {
		if err := c.runtime.storageService.StopContainer(c.ID()); err != nil {
			return errors.Wrapf(err, "error unmounting container %s root filesystem", c.ID())
		}

		c.state.Mounted = false
	}

	if err := c.runtime.storageService.DeleteContainer(c.ID()); err != nil {
		return errors.Wrapf(err, "error removing container %s root filesystem", c.ID())
	}

	return nil
}

// Init creates a container in the OCI runtime
func (c *Container) Init() (err error) {
	c.lock.Lock()
	defer c.lock.Unlock()

	if err := c.syncContainer(); err != nil {
		return err
	}

	if c.state.State != ContainerStateConfigured {
		return errors.Wrapf(ErrCtrExists, "container %s has already been created in runtime", c.ID())
	}

	mountPoint, err := c.runtime.storageService.StartContainer(c.ID())
	if err != nil {
		return errors.Wrapf(err, "error mounting storage for container %s", c.ID())
	}
	c.state.Mounted = true
	c.state.Mountpoint = mountPoint

	logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint)

	defer func() {
		if err != nil {
			if err2 := c.runtime.storageService.StopContainer(c.ID()); err2 != nil {
				logrus.Errorf("Error unmounting storage for container %s: %v", c.ID(), err2)
			}

			c.state.Mounted = false
			c.state.Mountpoint = ""
		}
	}()

	// Make the OCI runtime spec we will use
	c.runningSpec = new(spec.Spec)
	deepcopier.Copy(c.config.Spec).To(c.runningSpec)
	c.runningSpec.Root.Path = c.state.Mountpoint
	c.runningSpec.Annotations[crioAnnotations.Created] = c.config.CreatedTime.Format(time.RFC3339Nano)
	c.runningSpec.Annotations["org.opencontainers.image.stopSignal"] = fmt.Sprintf("%d", c.config.StopSignal)

	// Save the OCI spec to disk
	jsonPath := filepath.Join(c.bundlePath(), "config.json")
	fileJSON, err := json.Marshal(c.runningSpec)
	if err != nil {
		return errors.Wrapf(err, "error exporting runtime spec for container %s to JSON", c.ID())
	}
	if err := ioutil.WriteFile(jsonPath, fileJSON, 0644); err != nil {
		return errors.Wrapf(err, "error writing runtime spec JSON to file for container %s", c.ID())
	}
	c.state.ConfigPath = jsonPath

	logrus.Debugf("Created OCI spec for container %s at %s", c.ID(), jsonPath)

	// With the spec complete, do an OCI create
	// TODO set cgroup parent in a sane fashion
	if err := c.runtime.ociRuntime.createContainer(c, "/libpod_parent"); err != nil {
		return err
	}

	logrus.Debugf("Created container %s in runc", c.ID())

	c.state.State = ContainerStateCreated

	if err := c.runtime.state.SaveContainer(c); err != nil {
		return errors.Wrapf(err, "error saving container %s state", c.ID())
	}

	return nil
}

// Start starts a container
func (c *Container) Start() error {
	c.lock.Lock()
	defer c.lock.Unlock()

	if err := c.syncContainer(); err != nil {
		return err
	}

	// Container must be created or stopped to be started
	if !(c.state.State == ContainerStateCreated || c.state.State == ContainerStateStopped) {
		return errors.Wrapf(ErrCtrStateInvalid, "container %s must be in Created or Stopped state to be started", c.ID())
	}

	if err := c.runtime.ociRuntime.startContainer(c); err != nil {
		return err
	}

	logrus.Debugf("Started container %s", c.ID())

	// Update container's state as it should be ContainerStateRunning now
	if err := c.runtime.ociRuntime.updateContainerStatus(c); err != nil {
		return err
	}

	if err := c.runtime.state.SaveContainer(c); err != nil {
		return errors.Wrapf(err, "error saving container %s state", c.ID())
	}

	return nil
}

// Stop stops a container
func (c *Container) Stop() error {
	return ErrNotImplemented
}

// Kill sends a signal to a container
func (c *Container) Kill(signal uint) error {
	return ErrNotImplemented
}

// Exec starts a new process inside the container
// Returns fully qualified URL of streaming server for executed process
func (c *Container) Exec(cmd []string, tty bool, stdin bool) (string, error) {
	return "", ErrNotImplemented
}

// Attach attaches to a container
// Returns fully qualified URL of streaming server for the container
func (c *Container) Attach(noStdin bool, keys string, attached chan<- bool) error {
	if err := c.syncContainer(); err != nil {
		return err
	}

	if c.state.State == ContainerStateRunning || c.state.State == ContainerStatePaused {
		return errors.Wrapf(ErrCtrStateInvalid, "cannot remove storage for container %s as it is running or paused", c.ID())
	}

	// TODO is it valid to attach to a frozen container?
	if c.state.State == ContainerStateUnknown ||
		c.state.State == ContainerStateConfigured ||
		c.state.State == ContainerStatePaused {
		return errors.Wrapf(ErrCtrStateInvalid, "can only attach to created, running, or stopped containers")
	}

	// Check the validity of the provided keys first
	var err error
	detachKeys := []byte{}
	if len(keys) > 0 {
		detachKeys, err = term.ToBytes(keys)
		if err != nil {
			return errors.Wrapf(err, "invalid detach keys")
		}
	}

	resize := make(chan remotecommand.TerminalSize)
	defer close(resize)

	err = c.attachContainerSocket(resize, noStdin, detachKeys, attached)
	return err
}

// Mount mounts a container's filesystem on the host
// The path where the container has been mounted is returned
func (c *Container) Mount() (string, error) {
	return "", ErrNotImplemented
}

// Pause pauses a container
func (c *Container) Pause() error {
	return ErrNotImplemented
}

// Unpause unpauses a container
func (c *Container) Unpause() error {
	return ErrNotImplemented
}

// Export exports a container's root filesystem as a tar archive
// The archive will be saved as a file at the given path
func (c *Container) Export(path string) error {
	c.lock.Lock()
	defer c.lock.Unlock()

	if err := c.syncContainer(); err != nil {
		return err
	}

	mountPoint := c.state.Mountpoint
	if !c.state.Mounted {
		mount, err := c.runtime.store.Mount(c.ID(), c.config.MountLabel)
		if err != nil {
			return errors.Wrapf(err, "error mounting container %q", c.ID())
		}
		mountPoint = mount
		defer func() {
			if err := c.runtime.store.Unmount(c.ID()); err != nil {
				logrus.Errorf("error unmounting container %q: %v", c.ID(), err)
			}
		}()
	}

	input, err := archive.Tar(mountPoint, archive.Uncompressed)
	if err != nil {
		return errors.Wrapf(err, "error reading container directory %q", c.ID())
	}

	outFile, err := os.Create(path)
	if err != nil {
		return errors.Wrapf(err, "error creating file %q", path)
	}
	defer outFile.Close()

	_, err = io.Copy(outFile, input)
	return err
}

// Commit commits the changes between a container and its image, creating a new
// image
func (c *Container) Commit() (*storage.Image, error) {
	return nil, ErrNotImplemented
}