aboutsummaryrefslogtreecommitdiff
path: root/libpod/storage.go
blob: 10827f13e7f7102b07387a073bbfe52230693073 (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
package libpod

import (
	"context"
	"encoding/json"
	"time"

	istorage "github.com/containers/image/storage"
	"github.com/containers/image/types"
	"github.com/containers/storage"
	"github.com/opencontainers/image-spec/specs-go/v1"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

type storageService struct {
	store storage.Store
}

// getStorageService returns a storageService which can create container root
// filesystems from images
func getStorageService(store storage.Store) (*storageService, error) {
	return &storageService{store: store}, nil
}

// ContainerInfo wraps a subset of information about a container: the locations
// of its nonvolatile and volatile per-container directories, along with a copy
// of the configuration blob from the image that was used to create the
// container, if the image had a configuration.
type ContainerInfo struct {
	Dir    string
	RunDir string
	Config *v1.Image
}

// RuntimeContainerMetadata is the structure that we encode as JSON and store
// in the metadata field of storage.Container objects.  It is used for
// specifying attributes containers when they are being created, and allows a
// container's MountLabel, and possibly other values, to be modified in one
// read/write cycle via calls to storageService.ContainerMetadata,
// RuntimeContainerMetadata.SetMountLabel, and
// storageService.SetContainerMetadata.
type RuntimeContainerMetadata struct {
	// The provided name and the ID of the image that was used to
	// instantiate the container.
	ImageName string `json:"image-name"` // Applicable to both PodSandboxes and Containers
	ImageID   string `json:"image-id"`   // Applicable to both PodSandboxes and Containers
	// The container's name, which for an infrastructure container is usually PodName + "-infra".
	ContainerName string `json:"name"`                 // Applicable to both PodSandboxes and Containers, mandatory
	CreatedAt     int64  `json:"created-at"`           // Applicable to both PodSandboxes and Containers
	MountLabel    string `json:"mountlabel,omitempty"` // Applicable to both PodSandboxes and Containers
}

// SetMountLabel updates the mount label held by a RuntimeContainerMetadata
// object.
func (metadata *RuntimeContainerMetadata) SetMountLabel(mountLabel string) {
	metadata.MountLabel = mountLabel
}

// CreateContainerStorage creates the storage end of things.  We already have the container spec created
// TO-DO We should be passing in an Image object in the future.
func (r *storageService) CreateContainerStorage(ctx context.Context, systemContext *types.SystemContext, imageName, imageID, containerName, containerID, mountLabel string, options *storage.ContainerOptions) (cinfo ContainerInfo, err error) {
	var imageConfig *v1.Image
	if imageName != "" {
		var ref types.ImageReference
		if containerName == "" {
			return ContainerInfo{}, ErrEmptyID
		}
		// Check if we have the specified image.
		ref, err := istorage.Transport.ParseStoreReference(r.store, imageID)
		if err != nil {
			return ContainerInfo{}, err
		}
		img, err := istorage.Transport.GetStoreImage(r.store, ref)
		if err != nil {
			return ContainerInfo{}, err
		}
		// Pull out a copy of the image's configuration.
		image, err := ref.NewImage(ctx, systemContext)
		if err != nil {
			return ContainerInfo{}, err
		}
		defer image.Close()

		// Get OCI configuration of image
		imageConfig, err = image.OCIConfig(ctx)
		if err != nil {
			return ContainerInfo{}, err
		}

		// Update the image name and ID.
		if imageName == "" && len(img.Names) > 0 {
			imageName = img.Names[0]
		}
		imageID = img.ID
	}

	// Build metadata to store with the container.
	metadata := RuntimeContainerMetadata{
		ImageName:     imageName,
		ImageID:       imageID,
		ContainerName: containerName,
		CreatedAt:     time.Now().Unix(),
		MountLabel:    mountLabel,
	}
	mdata, err := json.Marshal(&metadata)
	if err != nil {
		return ContainerInfo{}, err
	}

	// Build the container.
	names := []string{containerName}

	if options == nil {
		options = &storage.ContainerOptions{
			IDMappingOptions: storage.IDMappingOptions{
				HostUIDMapping: true,
				HostGIDMapping: true,
			},
		}
	}
	container, err := r.store.CreateContainer(containerID, names, imageID, "", string(mdata), options)
	if err != nil {
		logrus.Debugf("failed to create container %s(%s): %v", metadata.ContainerName, containerID, err)

		return ContainerInfo{}, err
	}
	logrus.Debugf("created container %q", container.ID)

	// If anything fails after this point, we need to delete the incomplete
	// container before returning.
	defer func() {
		if err != nil {
			if err2 := r.store.DeleteContainer(container.ID); err2 != nil {
				logrus.Infof("%v deleting partially-created container %q", err2, container.ID)

				return
			}
			logrus.Infof("deleted partially-created container %q", container.ID)
		}
	}()

	// Add a name to the container's layer so that it's easier to follow
	// what's going on if we're just looking at the storage-eye view of things.
	layerName := metadata.ContainerName + "-layer"
	names, err = r.store.Names(container.LayerID)
	if err != nil {
		return ContainerInfo{}, err
	}
	names = append(names, layerName)
	err = r.store.SetNames(container.LayerID, names)
	if err != nil {
		return ContainerInfo{}, err
	}

	// Find out where the container work directories are, so that we can return them.
	containerDir, err := r.store.ContainerDirectory(container.ID)
	if err != nil {
		return ContainerInfo{}, err
	}
	logrus.Debugf("container %q has work directory %q", container.ID, containerDir)

	containerRunDir, err := r.store.ContainerRunDirectory(container.ID)
	if err != nil {
		return ContainerInfo{}, err
	}
	logrus.Debugf("container %q has run directory %q", container.ID, containerRunDir)

	return ContainerInfo{
		Dir:    containerDir,
		RunDir: containerRunDir,
		Config: imageConfig,
	}, nil
}

func (r *storageService) DeleteContainer(idOrName string) error {
	if idOrName == "" {
		return ErrEmptyID
	}
	container, err := r.store.Container(idOrName)
	if err != nil {
		return err
	}
	err = r.store.DeleteContainer(container.ID)
	if err != nil {
		logrus.Debugf("failed to delete container %q: %v", container.ID, err)
		return err
	}
	return nil
}

func (r *storageService) SetContainerMetadata(idOrName string, metadata RuntimeContainerMetadata) error {
	mdata, err := json.Marshal(&metadata)
	if err != nil {
		logrus.Debugf("failed to encode metadata for %q: %v", idOrName, err)
		return err
	}
	return r.store.SetMetadata(idOrName, string(mdata))
}

func (r *storageService) GetContainerMetadata(idOrName string) (RuntimeContainerMetadata, error) {
	metadata := RuntimeContainerMetadata{}
	mdata, err := r.store.Metadata(idOrName)
	if err != nil {
		return metadata, err
	}
	if err = json.Unmarshal([]byte(mdata), &metadata); err != nil {
		return metadata, err
	}
	return metadata, nil
}

func (r *storageService) MountContainerImage(idOrName string) (string, error) {
	container, err := r.store.Container(idOrName)
	if err != nil {
		if errors.Cause(err) == storage.ErrContainerUnknown {
			return "", ErrNoSuchCtr
		}
		return "", err
	}
	metadata := RuntimeContainerMetadata{}
	if err = json.Unmarshal([]byte(container.Metadata), &metadata); err != nil {
		return "", err
	}
	mountPoint, err := r.store.Mount(container.ID, metadata.MountLabel)
	if err != nil {
		logrus.Debugf("failed to mount container %q: %v", container.ID, err)
		return "", err
	}
	logrus.Debugf("mounted container %q at %q", container.ID, mountPoint)
	return mountPoint, nil
}

func (r *storageService) UnmountContainerImage(idOrName string, force bool) (bool, error) {
	if idOrName == "" {
		return false, ErrEmptyID
	}
	container, err := r.store.Container(idOrName)
	if err != nil {
		return false, err
	}

	if !force {
		mounted, err := r.store.Mounted(container.ID)
		if err != nil {
			return false, err
		}
		if mounted == 0 {
			return false, storage.ErrLayerNotMounted
		}
	}
	mounted, err := r.store.Unmount(container.ID, force)
	if err != nil {
		logrus.Debugf("failed to unmount container %q: %v", container.ID, err)
		return false, err
	}
	logrus.Debugf("unmounted container %q", container.ID)
	return mounted, nil
}

func (r *storageService) MountedContainerImage(idOrName string) (int, error) {
	if idOrName == "" {
		return 0, ErrEmptyID
	}
	container, err := r.store.Container(idOrName)
	if err != nil {
		return 0, err
	}
	mounted, err := r.store.Mounted(container.ID)
	if err != nil {
		return 0, err
	}
	return mounted, nil
}

func (r *storageService) GetMountpoint(id string) (string, error) {
	container, err := r.store.Container(id)
	if err != nil {
		if errors.Cause(err) == storage.ErrContainerUnknown {
			return "", ErrNoSuchCtr
		}
		return "", err
	}
	layer, err := r.store.Layer(container.LayerID)
	if err != nil {
		return "", err
	}

	return layer.MountPoint, nil
}

func (r *storageService) GetWorkDir(id string) (string, error) {
	container, err := r.store.Container(id)
	if err != nil {
		if errors.Cause(err) == storage.ErrContainerUnknown {
			return "", ErrNoSuchCtr
		}
		return "", err
	}
	return r.store.ContainerDirectory(container.ID)
}

func (r *storageService) GetRunDir(id string) (string, error) {
	container, err := r.store.Container(id)
	if err != nil {
		if errors.Cause(err) == storage.ErrContainerUnknown {
			return "", ErrNoSuchCtr
		}
		return "", err
	}
	return r.store.ContainerRunDirectory(container.ID)
}