/
systemd.go
1747 lines (1537 loc) · 53.2 KB
/
systemd.go
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
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// -*- Mode: Go; indent-tabs-mode: t -*-
/*
* Copyright (C) 2014-2022 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package systemd
import (
"bufio"
"bytes"
"encoding/json"
"errors"
"fmt"
"io"
"os"
"os/exec"
"path/filepath"
"regexp"
"strconv"
"strings"
"sync"
"sync/atomic"
"text/template"
"time"
"github.com/snapcore/snapd/dirs"
"github.com/snapcore/snapd/gadget/quantity"
"github.com/snapcore/snapd/osutil"
"github.com/snapcore/snapd/osutil/squashfs"
"github.com/snapcore/snapd/sandbox/selinux"
"github.com/snapcore/snapd/strutil"
)
var (
// The output of 'systemctl show' for the ActiveState property must
// either be 'failed' or 'inactive' to detect as a valid stop. Any
// other value, including no output, results in an assumption that
// the queried service(s) are still running.
isStopDone = regexp.MustCompile(`(?m)\AActiveState=(?:failed|inactive)$`).Match
// how much time should Stop wait between calls to show
stopCheckDelay = 250 * time.Millisecond
// Empirical test results on slower targets (i.e. on Raspberry Pi 3)
// show that trying to stop 4 systemd units under heavy CPU and IO
// load can take 750ms to complete. Only generate notifications for
// units still running after 1 second to minimize noise.
stopNotifyDelay = time.Second
// daemonReloadLock is a package level lock to ensure that we
// do not run any `systemd daemon-reload` while a
// daemon-reload is in progress or a mount unit is
// generated/activated.
//
// See https://github.com/systemd/systemd/issues/10872 for the
// upstream systemd bug
daemonReloadLock extMutex
osutilIsMounted = osutil.IsMounted
// allow mocking the systemd version
Version = getVersion
// allow replacing the systemd implementation with a mock one
newSystemd = newSystemdReal
)
// mu is a sync.Mutex that also supports to check if the lock is taken
type extMutex struct {
lock sync.Mutex
muC int32
}
// Lock acquires the mutex
func (m *extMutex) Lock() {
m.lock.Lock()
atomic.AddInt32(&m.muC, 1)
}
// Unlock releases the mutex
func (m *extMutex) Unlock() {
atomic.AddInt32(&m.muC, -1)
m.lock.Unlock()
}
// Taken will panic with the given error message if the lock is not
// taken when this code runs. This is useful to internally check if
// something is accessed without a valid lock.
func (m *extMutex) Taken(errMsg string) {
if atomic.LoadInt32(&m.muC) != 1 {
panic("internal error: " + errMsg)
}
}
// MockNewSystemd can be used to replace the constructor of the
// Systemd types with a function that returns a mock object.
func MockNewSystemd(f func(be Backend, rootDir string, mode InstanceMode, rep Reporter) Systemd) func() {
oldNewSystemd := newSystemd
newSystemd = f
return func() {
newSystemd = oldNewSystemd
}
}
// systemctlCmd calls systemctl with the given args, returning its standard output (and wrapped error)
var systemctlCmd = func(args ...string) ([]byte, error) {
bs, stderr, err := osutil.RunSplitOutput("systemctl", args...)
if err != nil {
exitCode, runErr := osutil.ExitCode(err)
return nil, &Error{cmd: args, exitCode: exitCode, runErr: runErr,
msg: osutil.CombineStdOutErr(bs, stderr)}
}
return bs, nil
}
func MockSystemdVersion(version int, injectedError error) (restore func()) {
osutil.MustBeTestBinary("cannot mock systemd version outside of tests")
old := Version
Version = func() (int, error) {
return version, injectedError
}
return func() {
Version = old
}
}
// MockSystemctl allows to mock the systemctl invocations.
// The provided function will be called when systemctl would be invoked.
// The function can return the output and an error.
func MockSystemctl(f func(args ...string) ([]byte, error)) func() {
var mutex sync.Mutex
oldSystemctlCmd := systemctlCmd
systemctlCmd = func(args ...string) ([]byte, error) {
// Thread-safe wrapper to call the locked systemctl
mutex.Lock()
defer mutex.Unlock()
return f(args...)
}
return func() {
systemctlCmd = oldSystemctlCmd
}
}
// MockSystemctlWithDelay allows to mock the systemctl invocations.
// The provided function will be called when systemctl would be invoked.
// The function can return the output and an error. Also the function
// can return a delay that will be respected before completing the
// mocked invocation.
func MockSystemctlWithDelay(f func(args ...string) ([]byte, time.Duration, error)) func() {
var mutex sync.Mutex
oldSystemctlCmd := systemctlCmd
systemctlCmd = func(args ...string) (bs []byte, err error) {
// Thread-safe wrapper to call the locked systemctl
var delay time.Duration
func() {
mutex.Lock()
defer mutex.Unlock()
bs, delay, err = f(args...)
}()
// Emulate the delay outside the lock
time.Sleep(delay)
return bs, err
}
return func() {
systemctlCmd = oldSystemctlCmd
}
}
// MockStopDelays is used from tests so that Stop can be less
// forgiving there.
func MockStopDelays(checkDelay, notifyDelay time.Duration) func() {
oldCheckDelay := stopCheckDelay
oldNotifyDelay := stopNotifyDelay
stopCheckDelay = checkDelay
stopNotifyDelay = notifyDelay
return func() {
stopCheckDelay = oldCheckDelay
stopNotifyDelay = oldNotifyDelay
}
}
func Available() error {
_, err := systemctlCmd("--version")
return err
}
// getVersion returns systemd version.
func getVersion() (int, error) {
out, err := systemctlCmd("--version")
if err != nil {
return 0, err
}
// systemd version outpus is two lines - actual version and a list
// of features, e.g:
// systemd 229
// +PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP ...
//
// The version string may have extra data (a case on newer ubuntu), e.g:
// systemd 245 (245.4-4ubuntu3)
r := bufio.NewScanner(bytes.NewReader(out))
r.Split(bufio.ScanWords)
var verstr string
for i := 0; i < 2; i++ {
if !r.Scan() {
return 0, fmt.Errorf("cannot read systemd version: %v", r.Err())
}
s := r.Text()
if i == 0 && s != "systemd" {
return 0, fmt.Errorf("cannot parse systemd version: expected \"systemd\", got %q", s)
}
if i == 1 {
verstr = strings.TrimSpace(s)
}
}
ver, err := strconv.Atoi(verstr)
if err != nil {
return 0, fmt.Errorf("cannot convert systemd version to number: %s", verstr)
}
return ver, nil
}
type systemdTooOldError struct {
expected int
got int
}
func (e *systemdTooOldError) Error() string {
return fmt.Sprintf("systemd version %d is too old (expected at least %d)", e.got, e.expected)
}
// IsSystemdTooOld returns true if the error is a result of a failed
// check whether systemd version is at least what was asked for.
func IsSystemdTooOld(err error) bool {
_, ok := err.(*systemdTooOldError)
return ok
}
// EnsureAtLeast checks whether the installed version of systemd is greater or
// equal than the given one. An error is returned if the required version is
// not matched, and also if systemd is not installed or not working
func EnsureAtLeast(requiredVersion int) error {
version, err := Version()
if err != nil {
return err
}
if version < requiredVersion {
return &systemdTooOldError{got: version, expected: requiredVersion}
}
return nil
}
var osutilStreamCommand = osutil.StreamCommand
// jctl calls journalctl to get the JSON logs of the given services.
var jctl = func(svcs []string, n int, follow, namespaces bool) (io.ReadCloser, error) {
// args will need two entries per service, plus a fixed number (give or take
// one) for the initial options.
args := make([]string, 0, 2*len(svcs)+7) // We have at most 7 extra arguments
args = append(args, "-o", "json", "--no-pager") // 3...
if n < 0 {
args = append(args, "--no-tail") // < 2
} else {
args = append(args, "-n", strconv.Itoa(n)) // ... + 2 ...
}
if follow {
args = append(args, "-f") // ... + 1 == 6
}
if namespaces {
args = append(args, "--namespace=*") // ... + 1 == 7
}
for i := range svcs {
args = append(args, "-u", svcs[i]) // this is why 2×
}
return osutilStreamCommand("journalctl", args...)
}
func MockJournalctl(f func(svcs []string, n int, follow, namespaces bool) (io.ReadCloser, error)) func() {
oldJctl := jctl
jctl = f
return func() {
jctl = oldJctl
}
}
// MountUnitType is an enum for the supported mount unit types.
type MountUnitType int
const (
// RegularMountUnit is a mount with the usual dependencies
RegularMountUnit MountUnitType = iota
// BeforeDriversLoadMountUnit mounts things before kernel modules are
// loaded either by udevd or by systemd-modules-load.service.
BeforeDriversLoadMountUnit
)
type MountUnitOptions struct {
// MountUnitType is the type of mount unit we want
MountUnitType MountUnitType
// Whether the unit is transient or persistent across reboots
Lifetime UnitLifetime
Description string
What string
Where string
Fstype string
Options []string
Origin string
// PreventRestartIfModified is set if we do not want to restart the
// mount unit if modified
PreventRestartIfModified bool
}
// Backend identifies the implementation backend in use by a Systemd instance.
type Backend int
const (
// RunningSystemdBackend identifies the implementation backend
// talking to the running system systemd daemon.
RunningSystemdBackend Backend = iota
// EmulationModeBackend identifies the implementation backend
// emulating a subset of systemd against a filesystem.
EmulationModeBackend
)
type mountUpdateStatus int
const (
mountUnchanged mountUpdateStatus = iota
mountUpdated
mountCreated
)
// EnsureMountUnitFlags contains flags that modify behavior of EnsureMountUnitFile
// TODO should we call directly EnsureMountUnitFileWithOptions and
// remove this type instead?
type EnsureMountUnitFlags struct {
// PreventRestartIfModified is set if we do not want to restart the
// mount unit if even though it was modified
PreventRestartIfModified bool
// StartBeforeDriversLoad is set if the unit is needed before
// udevd starts to run rules
StartBeforeDriversLoad bool
}
// Systemd exposes a minimal interface to manage systemd via the systemctl command.
type Systemd interface {
// Backend returns the underlying implementation backend.
Backend() Backend
// DaemonReload reloads systemd's configuration.
DaemonReload() error
// DaemonRexec reexecutes systemd's system manager, should be
// only necessary to apply manager's configuration like
// watchdog.
DaemonReexec() error
// EnableNoReload the given services, do not reload systemd.
EnableNoReload(services []string) error
// DisableNoReload the given services, do not reload system.
DisableNoReload(services []string) error
// Start the given service or services.
Start(service []string) error
// StartNoBlock starts the given service or services non-blocking.
StartNoBlock(service []string) error
// Stop the given service, and wait until it has stopped.
Stop(services []string) error
// Kill all processes of the unit with the given signal.
Kill(service, signal, who string) error
// Restart the service, waiting for it to stop before starting it again.
Restart(services []string) error
// Reload or restart the service via 'systemctl reload-or-restart'
ReloadOrRestart(services []string) error
// RestartNoWaitForStop restarts the given services using systemctl restart,
// with no snapd specific logic to wait for the services to stop.
RestartNoWaitForStop(services []string) error
// Status fetches the status of given units. Statuses are
// returned in the same order as unit names passed in
// argument.
Status(units []string) ([]*UnitStatus, error)
// InactiveEnterTimestamp returns the time that the given unit entered the
// inactive state as defined by the systemd docs. Specifically, this time is
// the most recent time in which the unit transitioned from deactivating
// ("Stopping") to dead ("Stopped"). It may be the zero time if this has
// never happened during the current boot, since this property is only
// tracked during the current boot. It specifically does not return a time
// that is monotonic, so the time returned here may be subject to bugs if
// there was a discontinuous time jump on the system before or during the
// unit's transition to inactive.
// TODO: incorporate this result into Status instead?
InactiveEnterTimestamp(unit string) (time.Time, error)
// IsEnabled checks whether the given service is enabled.
IsEnabled(service string) (bool, error)
// IsActive checks whether the given service is Active
IsActive(service string) (bool, error)
// LogReader returns a reader for the given services' log.
// If follow is set to true, the reader returned will follow the log
// as it grows.
// If namespaces is set to true, the log reader will include journal namespace
// logs, and is required to get logs for services which are in journal namespaces.
LogReader(services []string, n int, follow, namespaces bool) (io.ReadCloser, error)
// EnsureMountUnitFile adds/enables/starts a mount unit.
EnsureMountUnitFile(description, what, where, fstype string, flags EnsureMountUnitFlags) (string, error)
// EnsureMountUnitFileWithOptions adds/enables/starts a mount unit with options.
EnsureMountUnitFileWithOptions(unitOptions *MountUnitOptions) (string, error)
// RemoveMountUnitFile unmounts/stops/disables/removes a mount unit.
RemoveMountUnitFile(baseDir string) error
// ListMountUnits gets the list of targets of the mount units created by
// the `origin` module for the given snap
ListMountUnits(snapName, origin string) ([]string, error)
// Mask the given service.
Mask(service string) error
// Unmask the given service.
Unmask(service string) error
// Mount requests a mount of what under where with options.
Mount(what, where string, options ...string) error
// Umount requests a mount from what or at where to be unmounted.
Umount(whatOrWhere string) error
// CurrentMemoryUsage returns the current memory usage for the specified
// unit.
CurrentMemoryUsage(unit string) (quantity.Size, error)
// CurrentTasksCount returns the number of tasks (processes, threads, kernel
// threads if enabled, etc) part of the unit, which can be a service or a
// slice.
CurrentTasksCount(unit string) (uint64, error)
// Run a command
Run(command []string, opts *RunOptions) ([]byte, error)
}
// KeyringMode describes how the kernel keyring is setup, see systemd.exec(5)
type KeyringMode string
const (
KeyringModeInherit KeyringMode = "inherit"
KeyringModePrivate KeyringMode = "private"
KeyringModeShared KeyringMode = "shared"
)
// RunOptions can be passed to systemd.Run()
type RunOptions struct {
// XXX: alternative we could just have `Propertes []string` here
// and let the caller do the keyring setup but feels a bit loose
KeyringMode KeyringMode
Stdin io.Reader
Properties []string
}
// A Log is a single entry in the systemd journal.
// In almost all cases, the strings map to a single string value, but as per the
// manpage for journalctl, under the json format,
//
// Journal entries permit non-unique fields within the same log entry. JSON
// does not allow non-unique fields within objects. Due to this, if a
// non-unique field is encountered a JSON array is used as field value,
// listing all field values as elements.
//
// and this snippet as well,
//
// Fields containing non-printable or non-UTF8 bytes are
// encoded as arrays containing the raw bytes individually
// formatted as unsigned numbers.
//
// as such, we sometimes get array values which need to be handled differently,
// so we manually try to decode the json for each message into different types.
type Log map[string]*json.RawMessage
const (
// the default target for systemd units that we generate
ServicesTarget = "multi-user.target"
// the target prerequisite for systemd units we generate
PrerequisiteTarget = "network.target"
// the default target for systemd socket units that we generate
SocketsTarget = "sockets.target"
// the default target for systemd timer units that we generate
TimersTarget = "timers.target"
// the target for systemd user session units that we generate
UserServicesTarget = "default.target"
)
type Reporter interface {
Notify(string)
}
func newSystemdReal(be Backend, rootDir string, mode InstanceMode, rep Reporter) Systemd {
switch be {
case RunningSystemdBackend:
return &systemd{rootDir: rootDir, mode: mode, reporter: rep}
case EmulationModeBackend:
return &emulation{rootDir: rootDir}
default:
panic(fmt.Sprintf("unsupported systemd backend %v", be))
}
}
// New returns a Systemd that uses the default root directory and omits
// --root argument when executing systemctl.
func New(mode InstanceMode, rep Reporter) Systemd {
return newSystemd(RunningSystemdBackend, "", mode, rep)
}
// NewUnderRoot returns a Systemd that operates on the given rootdir.
func NewUnderRoot(rootDir string, mode InstanceMode, rep Reporter) Systemd {
return newSystemd(RunningSystemdBackend, rootDir, mode, rep)
}
// NewEmulationMode returns a Systemd that runs in emulation mode where
// systemd is not really called, but instead its functions are emulated
// by other means.
func NewEmulationMode(rootDir string) Systemd {
if rootDir == "" {
rootDir = dirs.GlobalRootDir
}
return newSystemd(EmulationModeBackend, rootDir, SystemMode, nil)
}
// InstanceMode determines which instance of systemd to control.
//
// SystemMode refers to the system instance (i.e. pid 1). UserMode
// refers to the instance launched to manage the user's desktop
// session. GlobalUserMode controls configuration respected by all
// user instances on the system.
//
// As GlobalUserMode does not refer to a single instance of systemd,
// some operations are not supported such as starting and stopping
// daemons.
type InstanceMode int
const (
SystemMode InstanceMode = iota
UserMode
GlobalUserMode
)
type systemd struct {
rootDir string
reporter Reporter
mode InstanceMode
}
func (s *systemd) systemctl(args ...string) ([]byte, error) {
switch s.mode {
case SystemMode:
case UserMode:
args = append([]string{"--user"}, args...)
case GlobalUserMode:
args = append([]string{"--user", "--global"}, args...)
default:
panic("unknown InstanceMode")
}
return systemctlCmd(args...)
}
func (s *systemd) Backend() Backend {
return RunningSystemdBackend
}
func (s *systemd) DaemonReload() error {
if s.mode == GlobalUserMode {
panic("cannot call daemon-reload with GlobalUserMode")
}
daemonReloadLock.Lock()
defer daemonReloadLock.Unlock()
return s.daemonReloadNoLock()
}
func (s *systemd) daemonReloadNoLock() error {
daemonReloadLock.Taken("cannot use daemon-reload without lock")
_, err := s.systemctl("daemon-reload")
return err
}
func (s *systemd) DaemonReexec() error {
if s.mode == GlobalUserMode {
panic("cannot call daemon-reexec with GlobalUserMode")
}
daemonReloadLock.Lock()
defer daemonReloadLock.Unlock()
_, err := s.systemctl("daemon-reexec")
return err
}
func (s *systemd) EnableNoReload(serviceNames []string) error {
if len(serviceNames) == 0 {
return nil
}
var args []string
if s.rootDir != "" {
// passing root already implies no reload
args = append(args, "--root", s.rootDir)
} else {
args = append(args, "--no-reload")
}
args = append(args, "enable")
args = append(args, serviceNames...)
_, err := s.systemctl(args...)
return err
}
func (s *systemd) Unmask(serviceName string) error {
var err error
if s.rootDir != "" {
_, err = s.systemctl("--root", s.rootDir, "unmask", serviceName)
} else {
_, err = s.systemctl("unmask", serviceName)
}
return err
}
func (s *systemd) DisableNoReload(serviceNames []string) error {
if len(serviceNames) == 0 {
return nil
}
var args []string
if s.rootDir != "" {
// passing root already implies no reload
args = append(args, "--root", s.rootDir)
} else {
args = append(args, "--no-reload")
}
args = append(args, "disable")
args = append(args, serviceNames...)
_, err := s.systemctl(args...)
return err
}
func (s *systemd) Mask(serviceName string) error {
var err error
if s.rootDir != "" {
_, err = s.systemctl("--root", s.rootDir, "mask", serviceName)
} else {
_, err = s.systemctl("mask", serviceName)
}
return err
}
func (s *systemd) Start(serviceNames []string) error {
if s.mode == GlobalUserMode {
panic("cannot call start with GlobalUserMode")
}
_, err := s.systemctl(append([]string{"start"}, serviceNames...)...)
return err
}
func (s *systemd) StartNoBlock(serviceNames []string) error {
if s.mode == GlobalUserMode {
panic("cannot call start with GlobalUserMode")
}
_, err := s.systemctl(append([]string{"start", "--no-block"}, serviceNames...)...)
return err
}
func (*systemd) LogReader(serviceNames []string, n int, follow, namespaces bool) (io.ReadCloser, error) {
return jctl(serviceNames, n, follow, namespaces)
}
var statusregex = regexp.MustCompile(`(?m)^(?:(.+?)=(.*)|(.*))?$`)
type UnitStatus struct {
Daemon string
// This is the real name ('Id') as returned by systemd.
Id string
// This is the name as used by the status requester (which could
// be a name alias). We always return the requester unit name as
// the actual unit name, in order to not confuse users.
Name string
// This is the actual list of unit names returned by systemd. This
// list always include the real name ('Id') as well as all the
// aliases for the unit.
Names []string
Enabled bool
Active bool
// Installed is false if the queried unit doesn't exist.
Installed bool
// NeedDaemonReload is true when systemd reports that the unit on disk
// has been modified and may differ from systemd's internal state, thus
// a daemon-reload is needed.
NeedDaemonReload bool
}
var baseProperties = []string{"Id", "ActiveState", "UnitFileState", "Names"}
var extendedProperties = []string{"Id", "ActiveState", "UnitFileState", "Type", "Names", "NeedDaemonReload"}
var unitProperties = map[string][]string{
".timer": baseProperties,
".socket": baseProperties,
".target": baseProperties,
// in service units, Type is the daemon type
".service": extendedProperties,
// in mount units, Type is the fs type
".mount": extendedProperties,
}
func (s *systemd) getUnitStatus(properties []string, unitNames []string) ([]*UnitStatus, error) {
cmd := make([]string, len(unitNames)+2)
cmd[0] = "show"
// ask for all properties, regardless of unit type
cmd[1] = "--property=" + strings.Join(properties, ",")
copy(cmd[2:], unitNames)
bs, err := s.systemctl(cmd...)
if err != nil {
return nil, err
}
sts := make([]*UnitStatus, 0, len(unitNames))
cur := &UnitStatus{}
seen := map[string]bool{}
for _, bs := range statusregex.FindAllSubmatch(bs, -1) {
if len(bs[0]) == 0 {
if len(sts) >= len(unitNames) {
return nil, fmt.Errorf("cannot get unit status: got more results than expected")
}
// The 'systemctl' command can return the status parameters for a
// number of units at the same time. The status output between
// units are separated with an empty line. Every parsed status
// is appended to the 'sts' array, so the n'th entry matches the
// n'th request, as ordered in 'unitNames'. The 'sts' array can
// therefore be used as an index to the original request.
requestIndex := len(sts)
// Record which unit 'Name' request produced this status because
// if the request was made using an aliased name, we must be
// consistent and reply using the same alias. We will check the
// validity of the alias below.
cur.Name = unitNames[requestIndex]
// systemctl separates data pertaining to particular services by an empty line
unitType := filepath.Ext(cur.Name)
expected := unitProperties[unitType]
if expected == nil {
expected = baseProperties
}
missing := make([]string, 0, len(expected))
for _, k := range expected {
if !seen[k] {
missing = append(missing, k)
}
}
if len(missing) > 0 {
return nil, fmt.Errorf("cannot get unit %q status: missing %s in ‘systemctl show’ output", cur.Name, strings.Join(missing, ", "))
}
// The 'Names' property from systemd exposes all the unit name aliases
// as well as the real name 'Id'. In order to verify if the request
// matches the reply, we should compare the request name 'Name' against
// the 'Names' list in case the request was made using a name alias
// (e.g. ctrl-alt-del.target). The 'Names' unit property exist for all
// derived 'Unit' types, including services, targets, sockets, mounts
// and timers. Do not assume 'Id' in 'Names' is first in the list from
// systemd.
if !(cur.Name == cur.Id || strutil.ListContains(cur.Names, cur.Name)) {
return nil, fmt.Errorf("cannot get unit status: queried status of %q but got status of %q", cur.Name, cur.Id)
}
sts = append(sts, cur)
cur = &UnitStatus{}
seen = map[string]bool{}
continue
}
if len(bs[3]) > 0 {
return nil, fmt.Errorf("cannot get unit status: bad line %q in ‘systemctl show’ output", bs[3])
}
k := string(bs[1])
v := string(bs[2])
if v == "" && k != "UnitFileState" && k != "Type" {
return nil, fmt.Errorf("cannot get unit status: empty field %q in ‘systemctl show’ output", k)
}
switch k {
case "Id":
cur.Id = v
case "Type":
cur.Daemon = v
case "ActiveState":
// made to match “systemctl is-active” behaviour, at least at systemd 229
cur.Active = v == "active" || v == "reloading"
case "UnitFileState":
// "static" means it can't be disabled
cur.Enabled = v == "enabled" || v == "static"
cur.Installed = v != ""
case "Names":
// This list can include Alias names for a unit (but also includes Id)
cur.Names = strings.Fields(v)
case "NeedDaemonReload":
cur.NeedDaemonReload = v == "yes"
default:
return nil, fmt.Errorf("cannot get unit status: unexpected field %q in ‘systemctl show’ output", k)
}
if seen[k] {
return nil, fmt.Errorf("cannot get unit status: duplicate field %q in ‘systemctl show’ output", k)
}
seen[k] = true
}
if len(sts) != len(unitNames) {
return nil, fmt.Errorf("cannot get unit status: expected %d results, got %d", len(unitNames), len(sts))
}
return sts, nil
}
func (s *systemd) getGlobalUserStatus(unitNames ...string) ([]*UnitStatus, error) {
// As there is one instance per user, the active state does
// not make sense. We can determine the global "enabled"
// state of the services though.
cmd := append([]string{"is-enabled"}, unitNames...)
if s.rootDir != "" {
cmd = append([]string{"--root", s.rootDir}, cmd...)
}
bs, err := s.systemctl(cmd...)
if err != nil {
// is-enabled returns non-zero if no units are
// enabled. We still need to examine the output to
// track the other units.
sysdErr := err.(systemctlError)
bs = sysdErr.Msg()
}
results := bytes.Split(bytes.Trim(bs, "\n"), []byte("\n"))
if len(results) != len(unitNames) {
return nil, fmt.Errorf("cannot get enabled status of services: expected %d results, got %d", len(unitNames), len(results))
}
sts := make([]*UnitStatus, len(unitNames))
for i, line := range results {
sts[i] = &UnitStatus{
Name: unitNames[i],
Enabled: bytes.Equal(line, []byte("enabled")) || bytes.Equal(line, []byte("static")),
}
}
return sts, nil
}
func (s *systemd) getPropertyStringValue(unit, key string) (string, error) {
// XXX: ignore stderr of systemctl command to avoid further infractions
// around LP #1885597
out, err := s.systemctl("show", "--property", key, unit)
if err != nil {
return "", osutil.OutputErr(out, err)
}
cleanVal := strings.TrimSpace(string(out))
// strip the <property>= from the output
splitVal := strings.SplitN(cleanVal, "=", 2)
if len(splitVal) != 2 {
return "", fmt.Errorf("invalid property format from systemd for %s (got %s)", key, cleanVal)
}
return strings.TrimSpace(splitVal[1]), nil
}
var errNotSet = errors.New("property value is not available")
func (s *systemd) getPropertyUintValue(unit, key string) (uint64, error) {
valStr, err := s.getPropertyStringValue(unit, key)
if err != nil {
return 0, err
}
// if the unit is inactive or doesn't exist, the value can be reported as
// "[not set]"
if valStr == "[not set]" {
return 0, errNotSet
}
intVal, err := strconv.ParseUint(valStr, 10, 64)
if err != nil {
return 0, fmt.Errorf("invalid property value from systemd for %s: cannot parse %q as an integer", key, valStr)
}
return intVal, nil
}
func (s *systemd) CurrentTasksCount(unit string) (uint64, error) {
tasksCount, err := s.getPropertyUintValue(unit, "TasksCurrent")
if err != nil && err != errNotSet {
return 0, err
}
if err == errNotSet {
return 0, fmt.Errorf("tasks count unavailable")
}
return tasksCount, nil
}
func (s *systemd) CurrentMemoryUsage(unit string) (quantity.Size, error) {
memBytes, err := s.getPropertyUintValue(unit, "MemoryCurrent")
if err != nil && err != errNotSet {
return 0, err
}
if err == errNotSet {
return 0, fmt.Errorf("memory usage unavailable")
}
return quantity.Size(memBytes), nil
}
func (s *systemd) InactiveEnterTimestamp(unit string) (time.Time, error) {
timeStr, err := s.getPropertyStringValue(unit, "InactiveEnterTimestamp")
if err != nil {
return time.Time{}, err
}
if timeStr == "" {
return time.Time{}, nil
}
// finally parse the time string
inactiveEnterTime, err := time.Parse("Mon 2006-01-02 15:04:05 MST", timeStr)
if err != nil {
return time.Time{}, fmt.Errorf("internal error: systemctl time output (%s) is malformed", timeStr)
}
return inactiveEnterTime, nil
}
func (s *systemd) Status(unitNames []string) ([]*UnitStatus, error) {
if s.mode == GlobalUserMode {
return s.getGlobalUserStatus(unitNames...)
}
unitToStatus := make(map[string]*UnitStatus, len(unitNames))
var limitedUnits []string
var extendedUnits []string
for _, name := range unitNames {
// Group units with the same query string together to
// optimize the number of 'systemctl' invocations.
if strings.HasSuffix(name, ".timer") || strings.HasSuffix(name, ".socket") || strings.HasSuffix(name, ".target") {
// Units using the baseProperties query
limitedUnits = append(limitedUnits, name)
} else {
// Units using the extendedProperties query
extendedUnits = append(extendedUnits, name)
}
}
for _, set := range []struct {
units []string
properties []string
}{
{units: extendedUnits, properties: extendedProperties},
{units: limitedUnits, properties: baseProperties},
} {
if len(set.units) == 0 {
continue
}
sts, err := s.getUnitStatus(set.properties, set.units)
if err != nil {
return nil, err
}
for _, status := range sts {
unitToStatus[status.Name] = status
}
}
// unpack to preserve the promised order
sts := make([]*UnitStatus, len(unitNames))
for idx, name := range unitNames {
var ok bool
sts[idx], ok = unitToStatus[name]
if !ok {
return nil, fmt.Errorf("cannot determine status of unit %q", name)
}
}
return sts, nil
}
func (s *systemd) IsEnabled(serviceName string) (bool, error) {
var err error
if s.rootDir != "" {
_, err = s.systemctl("--root", s.rootDir, "is-enabled", serviceName)
} else {
_, err = s.systemctl("is-enabled", serviceName)