summaryrefslogtreecommitdiff
path: root/pkg/specgen/generate/oci.go
blob: 4953735b119eb22c204f9749afe4f12e3ed5e03b (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
package generate

import (
	"context"
	"strings"

	"github.com/containers/common/pkg/config"
	"github.com/containers/libpod/v2/libpod"
	"github.com/containers/libpod/v2/libpod/define"
	"github.com/containers/libpod/v2/libpod/image"
	"github.com/containers/libpod/v2/pkg/rootless"
	"github.com/containers/libpod/v2/pkg/specgen"
	"github.com/opencontainers/runc/libcontainer/user"
	spec "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/opencontainers/runtime-tools/generate"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
	"golang.org/x/sys/unix"
)

func addRlimits(s *specgen.SpecGenerator, g *generate.Generator) error {
	var (
		isRootless = rootless.IsRootless()
		nofileSet  = false
		nprocSet   = false
	)

	if s.Rlimits == nil {
		g.Config.Process.Rlimits = nil
		return nil
	}

	for _, u := range s.Rlimits {
		name := "RLIMIT_" + strings.ToUpper(u.Type)
		if name == "RLIMIT_NOFILE" {
			nofileSet = true
		} else if name == "RLIMIT_NPROC" {
			nprocSet = true
		}
		g.AddProcessRlimits(name, u.Hard, u.Soft)
	}

	// If not explicitly overridden by the user, default number of open
	// files and number of processes to the maximum they can be set to
	// (without overriding a sysctl)
	if !nofileSet {
		max := define.RLimitDefaultValue
		current := define.RLimitDefaultValue
		if isRootless {
			var rlimit unix.Rlimit
			if err := unix.Getrlimit(unix.RLIMIT_NOFILE, &rlimit); err != nil {
				logrus.Warnf("failed to return RLIMIT_NOFILE ulimit %q", err)
			}
			if rlimit.Cur < current {
				current = rlimit.Cur
			}
			if rlimit.Max < max {
				max = rlimit.Max
			}
		}
		g.AddProcessRlimits("RLIMIT_NOFILE", max, current)
	}
	if !nprocSet {
		max := define.RLimitDefaultValue
		current := define.RLimitDefaultValue
		if isRootless {
			var rlimit unix.Rlimit
			if err := unix.Getrlimit(unix.RLIMIT_NPROC, &rlimit); err != nil {
				logrus.Warnf("failed to return RLIMIT_NPROC ulimit %q", err)
			}
			if rlimit.Cur < current {
				current = rlimit.Cur
			}
			if rlimit.Max < max {
				max = rlimit.Max
			}
		}
		g.AddProcessRlimits("RLIMIT_NPROC", max, current)
	}

	return nil
}

// Produce the final command for the container.
func makeCommand(ctx context.Context, s *specgen.SpecGenerator, img *image.Image, rtc *config.Config) ([]string, error) {
	finalCommand := []string{}

	entrypoint := s.Entrypoint
	if entrypoint == nil && img != nil {
		newEntry, err := img.Entrypoint(ctx)
		if err != nil {
			return nil, err
		}
		entrypoint = newEntry
	}

	finalCommand = append(finalCommand, entrypoint...)

	command := s.Command
	if command == nil && img != nil {
		newCmd, err := img.Cmd(ctx)
		if err != nil {
			return nil, err
		}
		command = newCmd
	}

	finalCommand = append(finalCommand, command...)

	if len(finalCommand) == 0 {
		return nil, errors.Errorf("no command or entrypoint provided, and no CMD or ENTRYPOINT from image")
	}

	if s.Init {
		initPath := s.InitPath
		if initPath == "" && rtc != nil {
			initPath = rtc.Engine.InitPath
		}
		if initPath == "" {
			return nil, errors.Errorf("no path to init binary found but container requested an init")
		}
		finalCommand = append([]string{"/dev/init", "--"}, finalCommand...)
	}

	return finalCommand, nil
}

func SpecGenToOCI(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Runtime, rtc *config.Config, newImage *image.Image, mounts []spec.Mount, pod *libpod.Pod, finalCmd []string) (*spec.Spec, error) {
	var (
		inUserNS bool
	)
	cgroupPerm := "ro"
	g, err := generate.New("linux")
	if err != nil {
		return nil, err
	}
	// Remove the default /dev/shm mount to ensure we overwrite it
	g.RemoveMount("/dev/shm")
	g.HostSpecific = true
	addCgroup := true
	canMountSys := true

	isRootless := rootless.IsRootless()
	if isRootless {
		inUserNS = true
	}
	if !s.UserNS.IsHost() {
		if s.UserNS.IsContainer() || s.UserNS.IsPath() {
			inUserNS = true
		}
		if s.UserNS.IsPrivate() {
			inUserNS = true
		}
	}
	if inUserNS && s.NetNS.IsHost() {
		canMountSys = false
	}

	if s.Privileged && canMountSys {
		cgroupPerm = "rw"
		g.RemoveMount("/sys")
		sysMnt := spec.Mount{
			Destination: "/sys",
			Type:        "sysfs",
			Source:      "sysfs",
			Options:     []string{"rprivate", "nosuid", "noexec", "nodev", "rw"},
		}
		g.AddMount(sysMnt)
	} else if !canMountSys {
		addCgroup = false
		g.RemoveMount("/sys")
		r := "ro"
		if s.Privileged {
			r = "rw"
		}
		sysMnt := spec.Mount{
			Destination: "/sys",
			Type:        "bind", // should we use a constant for this, like createconfig?
			Source:      "/sys",
			Options:     []string{"rprivate", "nosuid", "noexec", "nodev", r, "rbind"},
		}
		g.AddMount(sysMnt)
		if !s.Privileged && isRootless {
			g.AddLinuxMaskedPaths("/sys/kernel")
		}
	}
	gid5Available := true
	if isRootless {
		nGids, err := GetAvailableGids()
		if err != nil {
			return nil, err
		}
		gid5Available = nGids >= 5
	}
	// When using a different user namespace, check that the GID 5 is mapped inside
	// the container.
	if gid5Available && (s.IDMappings != nil && len(s.IDMappings.GIDMap) > 0) {
		mappingFound := false
		for _, r := range s.IDMappings.GIDMap {
			if r.ContainerID <= 5 && 5 < r.ContainerID+r.Size {
				mappingFound = true
				break
			}
		}
		if !mappingFound {
			gid5Available = false
		}

	}
	if !gid5Available {
		// If we have no GID mappings, the gid=5 default option would fail, so drop it.
		g.RemoveMount("/dev/pts")
		devPts := spec.Mount{
			Destination: "/dev/pts",
			Type:        "devpts",
			Source:      "devpts",
			Options:     []string{"rprivate", "nosuid", "noexec", "newinstance", "ptmxmode=0666", "mode=0620"},
		}
		g.AddMount(devPts)
	}

	if inUserNS && s.IpcNS.IsHost() {
		g.RemoveMount("/dev/mqueue")
		devMqueue := spec.Mount{
			Destination: "/dev/mqueue",
			Type:        "bind", // constant ?
			Source:      "/dev/mqueue",
			Options:     []string{"bind", "nosuid", "noexec", "nodev"},
		}
		g.AddMount(devMqueue)
	}
	if inUserNS && s.PidNS.IsHost() {
		g.RemoveMount("/proc")
		procMount := spec.Mount{
			Destination: "/proc",
			Type:        TypeBind,
			Source:      "/proc",
			Options:     []string{"rbind", "nosuid", "noexec", "nodev"},
		}
		g.AddMount(procMount)
	}

	if addCgroup {
		cgroupMnt := spec.Mount{
			Destination: "/sys/fs/cgroup",
			Type:        "cgroup",
			Source:      "cgroup",
			Options:     []string{"rprivate", "nosuid", "noexec", "nodev", "relatime", cgroupPerm},
		}
		g.AddMount(cgroupMnt)
	}
	g.SetProcessCwd(s.WorkDir)

	g.SetProcessArgs(finalCmd)

	g.SetProcessTerminal(s.Terminal)

	for key, val := range s.Annotations {
		g.AddAnnotation(key, val)
	}
	g.AddProcessEnv("container", "podman")

	g.Config.Linux.Resources = s.ResourceLimits

	// Devices
	if s.Privileged {
		// If privileged, we need to add all the host devices to the
		// spec.  We do not add the user provided ones because we are
		// already adding them all.
		if err := addPrivilegedDevices(&g); err != nil {
			return nil, err
		}
	} else {
		// add default devices from containers.conf
		for _, device := range rtc.Containers.Devices {
			if err := DevicesFromPath(&g, device); err != nil {
				return nil, err
			}
		}
		// add default devices specified by caller
		for _, device := range s.Devices {
			if err := DevicesFromPath(&g, device.Path); err != nil {
				return nil, err
			}
		}
	}

	// SECURITY OPTS
	g.SetProcessNoNewPrivileges(s.NoNewPrivileges)

	if !s.Privileged {
		g.SetProcessApparmorProfile(s.ApparmorProfile)
	}

	BlockAccessToKernelFilesystems(s.Privileged, s.PidNS.IsHost(), &g)

	for name, val := range s.Env {
		g.AddProcessEnv(name, val)
	}

	if err := addRlimits(s, &g); err != nil {
		return nil, err
	}

	// NAMESPACES
	if err := specConfigureNamespaces(s, &g, rt, pod); err != nil {
		return nil, err
	}
	configSpec := g.Config

	if err := securityConfigureGenerator(s, &g, newImage, rtc); err != nil {
		return nil, err
	}

	// BIND MOUNTS
	configSpec.Mounts = SupercedeUserMounts(mounts, configSpec.Mounts)
	// Process mounts to ensure correct options
	if err := InitFSMounts(configSpec.Mounts); err != nil {
		return nil, err
	}

	// Add annotations
	if configSpec.Annotations == nil {
		configSpec.Annotations = make(map[string]string)
	}

	if s.Remove {
		configSpec.Annotations[define.InspectAnnotationAutoremove] = define.InspectResponseTrue
	} else {
		configSpec.Annotations[define.InspectAnnotationAutoremove] = define.InspectResponseFalse
	}

	if len(s.VolumesFrom) > 0 {
		configSpec.Annotations[define.InspectAnnotationVolumesFrom] = strings.Join(s.VolumesFrom, ",")
	}

	if s.Privileged {
		configSpec.Annotations[define.InspectAnnotationPrivileged] = define.InspectResponseTrue
	} else {
		configSpec.Annotations[define.InspectAnnotationPrivileged] = define.InspectResponseFalse
	}

	if s.Init {
		configSpec.Annotations[define.InspectAnnotationInit] = define.InspectResponseTrue
	} else {
		configSpec.Annotations[define.InspectAnnotationInit] = define.InspectResponseFalse
	}

	return configSpec, nil
}

func GetAvailableGids() (int64, error) {
	idMap, err := user.ParseIDMapFile("/proc/self/gid_map")
	if err != nil {
		return 0, err
	}
	count := int64(0)
	for _, r := range idMap {
		count += r.Count
	}
	return count, nil
}