summaryrefslogtreecommitdiff
path: root/libpod/runtime_pod_linux.go
blob: e9ce130da300feb36d9dc9ec3e2672eaf1c91a66 (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
// +build linux

package libpod

import (
	"context"
	"fmt"
	"path"
	"path/filepath"
	"strings"

	"github.com/containers/libpod/libpod/define"
	"github.com/containers/libpod/libpod/events"
	"github.com/containers/libpod/pkg/cgroups"
	"github.com/containers/libpod/pkg/rootless"
	spec "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

// NewPod makes a new, empty pod
func (r *Runtime) NewPod(ctx context.Context, options ...PodCreateOption) (*Pod, error) {
	r.lock.Lock()
	defer r.lock.Unlock()

	if !r.valid {
		return nil, define.ErrRuntimeStopped
	}

	pod, err := newPod(r)
	if err != nil {
		return nil, errors.Wrapf(err, "error creating pod")
	}

	// Set default namespace to runtime's namespace
	// Do so before options run so they can override it
	if r.config.Namespace != "" {
		pod.config.Namespace = r.config.Namespace
	}

	for _, option := range options {
		if err := option(pod); err != nil {
			return nil, errors.Wrapf(err, "error running pod create option")
		}
	}

	if pod.config.Name == "" {
		name, err := r.generateName()
		if err != nil {
			return nil, err
		}
		pod.config.Name = name
	}

	// Allocate a lock for the pod
	lock, err := r.lockManager.AllocateLock()
	if err != nil {
		return nil, errors.Wrapf(err, "error allocating lock for new pod")
	}
	pod.lock = lock
	pod.config.LockID = pod.lock.ID()

	pod.valid = true

	// Check CGroup parent sanity, and set it if it was not set
	switch r.config.CgroupManager {
	case CgroupfsCgroupsManager:
		if pod.config.CgroupParent == "" {
			pod.config.CgroupParent = CgroupfsDefaultCgroupParent
		} else if strings.HasSuffix(path.Base(pod.config.CgroupParent), ".slice") {
			return nil, errors.Wrapf(define.ErrInvalidArg, "systemd slice received as cgroup parent when using cgroupfs")
		}
		// If we are set to use pod cgroups, set the cgroup parent that
		// all containers in the pod will share
		// No need to create it with cgroupfs - the first container to
		// launch should do it for us
		if pod.config.UsePodCgroup {
			pod.state.CgroupPath = filepath.Join(pod.config.CgroupParent, pod.ID())
		}
	case SystemdCgroupsManager:
		if pod.config.CgroupParent == "" {
			if rootless.IsRootless() {
				pod.config.CgroupParent = SystemdDefaultRootlessCgroupParent
			} else {
				pod.config.CgroupParent = SystemdDefaultCgroupParent
			}
		} else if len(pod.config.CgroupParent) < 6 || !strings.HasSuffix(path.Base(pod.config.CgroupParent), ".slice") {
			return nil, errors.Wrapf(define.ErrInvalidArg, "did not receive systemd slice as cgroup parent when using systemd to manage cgroups")
		}
		// If we are set to use pod cgroups, set the cgroup parent that
		// all containers in the pod will share
		if pod.config.UsePodCgroup {
			cgroupPath, err := systemdSliceFromPath(pod.config.CgroupParent, fmt.Sprintf("libpod_pod_%s", pod.ID()))
			if err != nil {
				return nil, errors.Wrapf(err, "unable to create pod cgroup for pod %s", pod.ID())
			}
			pod.state.CgroupPath = cgroupPath
		}
	default:
		return nil, errors.Wrapf(define.ErrInvalidArg, "unsupported CGroup manager: %s - cannot validate cgroup parent", r.config.CgroupManager)
	}

	if pod.config.UsePodCgroup {
		logrus.Debugf("Got pod cgroup as %s", pod.state.CgroupPath)
	}
	if !pod.HasInfraContainer() && pod.SharesNamespaces() {
		return nil, errors.Errorf("Pods must have an infra container to share namespaces")
	}
	if pod.HasInfraContainer() && !pod.SharesNamespaces() {
		logrus.Warnf("Pod has an infra container, but shares no namespaces")
	}

	if err := r.state.AddPod(pod); err != nil {
		return nil, errors.Wrapf(err, "error adding pod to state")
	}

	if pod.HasInfraContainer() {
		ctr, err := r.createInfraContainer(ctx, pod)
		if err != nil {
			// Tear down pod, as it is assumed a the pod will contain
			// a pause container, and it does not.
			if err2 := r.removePod(ctx, pod, true, true); err2 != nil {
				logrus.Errorf("Error removing pod after pause container creation failure: %v", err2)
			}
			return nil, errors.Wrapf(err, "error adding Infra Container")
		}
		pod.state.InfraContainerID = ctr.ID()
		if err := pod.save(); err != nil {
			return nil, err
		}
	}
	pod.newPodEvent(events.Create)
	return pod, nil
}

func (r *Runtime) removePod(ctx context.Context, p *Pod, removeCtrs, force bool) error {
	if err := p.updatePod(); err != nil {
		return err
	}

	ctrs, err := r.state.PodContainers(p)
	if err != nil {
		return err
	}

	numCtrs := len(ctrs)

	// If the only container in the pod is the pause container, remove the pod and container unconditionally.
	pauseCtrID := p.state.InfraContainerID
	if numCtrs == 1 && ctrs[0].ID() == pauseCtrID {
		removeCtrs = true
		force = true
	}
	if !removeCtrs && numCtrs > 0 {
		return errors.Wrapf(define.ErrCtrExists, "pod %s contains containers and cannot be removed", p.ID())
	}

	// Go through and lock all containers so we can operate on them all at
	// once.
	// First loop also checks that we are ready to go ahead and remove.
	for _, ctr := range ctrs {
		ctrLock := ctr.lock
		ctrLock.Lock()
		defer ctrLock.Unlock()

		// If we're force-removing, no need to check status.
		if force {
			continue
		}

		// Sync all containers
		if err := ctr.syncContainer(); err != nil {
			return err
		}

		// Ensure state appropriate for removal
		if err := ctr.checkReadyForRemoval(); err != nil {
			return errors.Wrapf(err, "pod %s has containers that are not ready to be removed", p.ID())
		}
	}

	var removalErr error

	// We're going to be removing containers.
	// If we are CGroupfs cgroup driver, to avoid races, we need to hit
	// the pod and conmon CGroups with a PID limit to prevent them from
	// spawning any further processes (particularly cleanup processes) which
	// would prevent removing the CGroups.
	if p.runtime.config.CgroupManager == CgroupfsCgroupsManager {
		// Get the conmon CGroup
		conmonCgroupPath := filepath.Join(p.state.CgroupPath, "conmon")
		conmonCgroup, err := cgroups.Load(conmonCgroupPath)
		if err != nil && err != cgroups.ErrCgroupDeleted {
			if removalErr == nil {
				removalErr = errors.Wrapf(err, "error retrieving pod %s conmon cgroup %s", p.ID(), conmonCgroupPath)
			} else {
				logrus.Errorf("Error retrieving pod %s conmon cgroup %s: %v", p.ID(), conmonCgroupPath, err)
			}
		}

		// New resource limits
		resLimits := new(spec.LinuxResources)
		resLimits.Pids = new(spec.LinuxPids)
		resLimits.Pids.Limit = 1 // Inhibit forks with very low pids limit

		// Don't try if we failed to retrieve the cgroup
		if err == nil {
			if err := conmonCgroup.Update(resLimits); err != nil {
				if removalErr == nil {
					removalErr = errors.Wrapf(err, "error updating pod %s conmon group", p.ID())
				} else {
					logrus.Errorf("Error updating pod %s conmon cgroup %s: %v", p.ID(), conmonCgroupPath, err)
				}
			}
		}
	}

	// Second loop - all containers are good, so we should be clear to
	// remove.
	for _, ctr := range ctrs {
		// Remove the container
		if err := r.removeContainer(ctx, ctr, force, true, true); err != nil {
			if removalErr != nil {
				removalErr = err
			} else {
				logrus.Errorf("Error removing container %s from pod %s: %v", ctr.ID(), p.ID(), err)
			}
		}
	}

	// Remove all containers in the pod from the state.
	if err := r.state.RemovePodContainers(p); err != nil {
		// If this fails, there isn't much more we can do.
		// The containers in the pod are unusable, but they still exist,
		// so pod removal will fail.
		return err
	}

	// Remove pod cgroup, if present
	if p.state.CgroupPath != "" {
		logrus.Debugf("Removing pod cgroup %s", p.state.CgroupPath)

		switch p.runtime.config.CgroupManager {
		case SystemdCgroupsManager:
			if err := deleteSystemdCgroup(p.state.CgroupPath); err != nil {
				if removalErr == nil {
					removalErr = errors.Wrapf(err, "error removing pod %s cgroup", p.ID())
				} else {
					logrus.Errorf("Error deleting pod %s cgroup %s: %v", p.ID(), p.state.CgroupPath, err)
				}
			}
		case CgroupfsCgroupsManager:
			// Delete the cgroupfs cgroup
			// Make sure the conmon cgroup is deleted first
			// Since the pod is almost gone, don't bother failing
			// hard - instead, just log errors.
			conmonCgroupPath := filepath.Join(p.state.CgroupPath, "conmon")
			conmonCgroup, err := cgroups.Load(conmonCgroupPath)
			if err != nil && err != cgroups.ErrCgroupDeleted {
				if removalErr == nil {
					removalErr = errors.Wrapf(err, "error retrieving pod %s conmon cgroup", p.ID())
				} else {
					logrus.Debugf("Error retrieving pod %s conmon cgroup %s: %v", p.ID(), conmonCgroupPath, err)
				}
			}
			if err == nil {
				if err := conmonCgroup.Delete(); err != nil {
					if removalErr == nil {
						removalErr = errors.Wrapf(err, "error removing pod %s conmon cgroup", p.ID())
					} else {
						logrus.Errorf("Error deleting pod %s conmon cgroup %s: %v", p.ID(), conmonCgroupPath, err)
					}
				}
			}
			cgroup, err := cgroups.Load(p.state.CgroupPath)
			if err != nil && err != cgroups.ErrCgroupDeleted {
				if removalErr == nil {
					removalErr = errors.Wrapf(err, "error retrieving pod %s cgroup", p.ID())
				} else {
					logrus.Errorf("Error retrieving pod %s cgroup %s: %v", p.ID(), p.state.CgroupPath, err)
				}
			}
			if err == nil {
				if err := cgroup.Delete(); err != nil {
					if removalErr == nil {
						removalErr = errors.Wrapf(err, "error removing pod %s cgroup", p.ID())
					} else {
						logrus.Errorf("Error deleting pod %s cgroup %s: %v", p.ID(), p.state.CgroupPath, err)
					}
				}
			}
		default:
			// This should be caught much earlier, but let's still
			// keep going so we make sure to evict the pod before
			// ending up with an inconsistent state.
			if removalErr == nil {
				removalErr = errors.Wrapf(define.ErrInternal, "unrecognized cgroup manager %s when removing pod %s cgroups", p.runtime.config.CgroupManager, p.ID())
			} else {
				logrus.Errorf("Unknown cgroups manager %s specified - cannot remove pod %s cgroup", p.runtime.config.CgroupManager, p.ID())
			}
		}
	}

	// Remove pod from state
	if err := r.state.RemovePod(p); err != nil {
		if removalErr != nil {
			logrus.Errorf("%v", removalErr)
		}
		return err
	}

	// Mark pod invalid
	p.valid = false
	p.newPodEvent(events.Remove)

	// Deallocate the pod lock
	if err := p.lock.Free(); err != nil {
		if removalErr == nil {
			removalErr = errors.Wrapf(err, "error freeing pod %s lock", p.ID())
		} else {
			logrus.Errorf("Error freeing pod %s lock: %v", p.ID(), err)
		}
	}

	return removalErr
}