-
Notifications
You must be signed in to change notification settings - Fork 82
/
kubernetes_worker.py
889 lines (715 loc) · 31.4 KB
/
kubernetes_worker.py
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
#!/usr/bin/env python
# Copyright 2015 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
import random
import shutil
import subprocess
import time
from shlex import split
from subprocess import check_call, check_output
from subprocess import CalledProcessError
from socket import gethostname
from charms import layer
from charms.layer import snap
from charms.reactive import hook
from charms.reactive import set_state, remove_state, is_state
from charms.reactive import when, when_any, when_not
from charms.kubernetes.common import get_version
from charms.kubernetes.flagmanager import FlagManager
from charms.reactive.helpers import data_changed, any_file_changed
from charms.templating.jinja2 import render
from charmhelpers.core import hookenv, unitdata
from charmhelpers.core.host import service_stop, service_restart
from charmhelpers.contrib.charmsupport import nrpe
# Override the default nagios shortname regex to allow periods, which we
# need because our bin names contain them (e.g. 'snap.foo.daemon'). The
# default regex in charmhelpers doesn't allow periods, but nagios itself does.
nrpe.Check.shortname_re = '[\.A-Za-z0-9-_]+$'
kubeconfig_path = '/root/cdk/kubeconfig'
os.environ['PATH'] += os.pathsep + os.path.join(os.sep, 'snap', 'bin')
db = unitdata.kv()
@hook('upgrade-charm')
def upgrade_charm():
# Trigger removal of PPA docker installation if it was previously set.
set_state('config.changed.install_from_upstream')
hookenv.atexit(remove_state, 'config.changed.install_from_upstream')
cleanup_pre_snap_services()
check_resources_for_upgrade_needed()
# Remove gpu.enabled state so we can reconfigure gpu-related kubelet flags,
# since they can differ between k8s versions
remove_state('kubernetes-worker.gpu.enabled')
kubelet_opts = FlagManager('kubelet')
kubelet_opts.destroy('feature-gates')
kubelet_opts.destroy('experimental-nvidia-gpus')
remove_state('kubernetes-worker.cni-plugins.installed')
remove_state('kubernetes-worker.config.created')
remove_state('kubernetes-worker.ingress.available')
set_state('kubernetes-worker.restart-needed')
def check_resources_for_upgrade_needed():
hookenv.status_set('maintenance', 'Checking resources')
resources = ['kubectl', 'kubelet', 'kube-proxy']
paths = [hookenv.resource_get(resource) for resource in resources]
if any_file_changed(paths):
set_upgrade_needed()
def set_upgrade_needed():
set_state('kubernetes-worker.snaps.upgrade-needed')
config = hookenv.config()
previous_channel = config.previous('channel')
require_manual = config.get('require-manual-upgrade')
if previous_channel is None or not require_manual:
set_state('kubernetes-worker.snaps.upgrade-specified')
def cleanup_pre_snap_services():
# remove old states
remove_state('kubernetes-worker.components.installed')
# disable old services
services = ['kubelet', 'kube-proxy']
for service in services:
hookenv.log('Stopping {0} service.'.format(service))
service_stop(service)
# cleanup old files
files = [
"/lib/systemd/system/kubelet.service",
"/lib/systemd/system/kube-proxy.service",
"/etc/default/kube-default",
"/etc/default/kubelet",
"/etc/default/kube-proxy",
"/srv/kubernetes",
"/usr/local/bin/kubectl",
"/usr/local/bin/kubelet",
"/usr/local/bin/kube-proxy",
"/etc/kubernetes"
]
for file in files:
if os.path.isdir(file):
hookenv.log("Removing directory: " + file)
shutil.rmtree(file)
elif os.path.isfile(file):
hookenv.log("Removing file: " + file)
os.remove(file)
# cleanup old flagmanagers
FlagManager('kubelet').destroy_all()
FlagManager('kube-proxy').destroy_all()
@when('config.changed.channel')
def channel_changed():
set_upgrade_needed()
@when('kubernetes-worker.snaps.upgrade-needed')
@when_not('kubernetes-worker.snaps.upgrade-specified')
def upgrade_needed_status():
msg = 'Needs manual upgrade, run the upgrade action'
hookenv.status_set('blocked', msg)
@when('kubernetes-worker.snaps.upgrade-specified')
def install_snaps():
check_resources_for_upgrade_needed()
channel = hookenv.config('channel')
hookenv.status_set('maintenance', 'Installing kubectl snap')
snap.install('kubectl', channel=channel, classic=True)
hookenv.status_set('maintenance', 'Installing kubelet snap')
snap.install('kubelet', channel=channel, classic=True)
hookenv.status_set('maintenance', 'Installing kube-proxy snap')
snap.install('kube-proxy', channel=channel, classic=True)
set_state('kubernetes-worker.snaps.installed')
set_state('kubernetes-worker.restart-needed')
remove_state('kubernetes-worker.snaps.upgrade-needed')
remove_state('kubernetes-worker.snaps.upgrade-specified')
@hook('stop')
def shutdown():
''' When this unit is destroyed:
- delete the current node
- stop the worker services
'''
try:
if os.path.isfile(kubeconfig_path):
kubectl('delete', 'node', gethostname())
except CalledProcessError:
hookenv.log('Failed to unregister node.')
service_stop('snap.kubelet.daemon')
service_stop('snap.kube-proxy.daemon')
@when('docker.available')
@when_not('kubernetes-worker.cni-plugins.installed')
def install_cni_plugins():
''' Unpack the cni-plugins resource '''
charm_dir = os.getenv('CHARM_DIR')
# Get the resource via resource_get
try:
archive = hookenv.resource_get('cni')
except Exception:
message = 'Error fetching the cni resource.'
hookenv.log(message)
hookenv.status_set('blocked', message)
return
if not archive:
hookenv.log('Missing cni resource.')
hookenv.status_set('blocked', 'Missing cni resource.')
return
# Handle null resource publication, we check if filesize < 1mb
filesize = os.stat(archive).st_size
if filesize < 1000000:
hookenv.status_set('blocked', 'Incomplete cni resource.')
return
hookenv.status_set('maintenance', 'Unpacking cni resource.')
unpack_path = '{}/files/cni'.format(charm_dir)
os.makedirs(unpack_path, exist_ok=True)
cmd = ['tar', 'xfvz', archive, '-C', unpack_path]
hookenv.log(cmd)
check_call(cmd)
apps = [
{'name': 'loopback', 'path': '/opt/cni/bin'}
]
for app in apps:
unpacked = '{}/{}'.format(unpack_path, app['name'])
app_path = os.path.join(app['path'], app['name'])
install = ['install', '-v', '-D', unpacked, app_path]
hookenv.log(install)
check_call(install)
# Used by the "registry" action. The action is run on a single worker, but
# the registry pod can end up on any worker, so we need this directory on
# all the workers.
os.makedirs('/srv/registry', exist_ok=True)
set_state('kubernetes-worker.cni-plugins.installed')
@when('kubernetes-worker.snaps.installed')
def set_app_version():
''' Declare the application version to juju '''
cmd = ['kubelet', '--version']
version = check_output(cmd)
hookenv.application_version_set(version.split(b' v')[-1].rstrip())
@when('kubernetes-worker.snaps.installed')
@when_not('kube-control.dns.available')
def notify_user_transient_status():
''' Notify to the user we are in a transient state and the application
is still converging. Potentially remotely, or we may be in a detached loop
wait state '''
# During deployment the worker has to start kubelet without cluster dns
# configured. If this is the first unit online in a service pool waiting
# to self host the dns pod, and configure itself to query the dns service
# declared in the kube-system namespace
hookenv.status_set('waiting', 'Waiting for cluster DNS.')
@when('kubernetes-worker.snaps.installed',
'kube-control.dns.available')
@when_not('kubernetes-worker.snaps.upgrade-needed')
def charm_status(kube_control):
'''Update the status message with the current status of kubelet.'''
update_kubelet_status()
def update_kubelet_status():
''' There are different states that the kubelet can be in, where we are
waiting for dns, waiting for cluster turnup, or ready to serve
applications.'''
services = [
'kubelet',
'kube-proxy'
]
failing_services = []
for service in services:
daemon = 'snap.{}.daemon'.format(service)
if not _systemctl_is_active(daemon):
failing_services.append(service)
if len(failing_services) == 0:
hookenv.status_set('active', 'Kubernetes worker running.')
else:
msg = 'Waiting for {} to start.'.format(','.join(failing_services))
hookenv.status_set('waiting', msg)
@when('certificates.available')
def send_data(tls):
'''Send the data that is required to create a server certificate for
this server.'''
# Use the public ip of this unit as the Common Name for the certificate.
common_name = hookenv.unit_public_ip()
# Create SANs that the tls layer will add to the server cert.
sans = [
hookenv.unit_public_ip(),
hookenv.unit_private_ip(),
gethostname()
]
# Create a path safe name by removing path characters from the unit name.
certificate_name = hookenv.local_unit().replace('/', '_')
# Request a server cert with this information.
tls.request_server_cert(common_name, sans, certificate_name)
@when('kube-api-endpoint.available', 'kube-control.dns.available',
'cni.available')
def watch_for_changes(kube_api, kube_control, cni):
''' Watch for configuration changes and signal if we need to restart the
worker services '''
servers = get_kube_api_servers(kube_api)
dns = kube_control.get_dns()
cluster_cidr = cni.get_config()['cidr']
if (data_changed('kube-api-servers', servers) or
data_changed('kube-dns', dns) or
data_changed('cluster-cidr', cluster_cidr)):
set_state('kubernetes-worker.restart-needed')
@when('kubernetes-worker.snaps.installed', 'kube-api-endpoint.available',
'tls_client.ca.saved', 'tls_client.client.certificate.saved',
'tls_client.client.key.saved', 'tls_client.server.certificate.saved',
'tls_client.server.key.saved',
'kube-control.dns.available', 'kube-control.auth.available',
'cni.available', 'kubernetes-worker.restart-needed')
def start_worker(kube_api, kube_control, auth_control, cni):
''' Start kubelet using the provided API and DNS info.'''
servers = get_kube_api_servers(kube_api)
# Note that the DNS server doesn't necessarily exist at this point. We know
# what its IP will eventually be, though, so we can go ahead and configure
# kubelet with that info. This ensures that early pods are configured with
# the correct DNS even though the server isn't ready yet.
dns = kube_control.get_dns()
cluster_cidr = cni.get_config()['cidr']
if cluster_cidr is None:
hookenv.log('Waiting for cluster cidr.')
return
creds = kube_control.get_auth_credentials()
data_changed('kube-control.creds', creds)
# set --allow-privileged flag for kubelet
set_privileged()
create_config(random.choice(servers), creds)
configure_worker_services(servers, dns, cluster_cidr)
set_state('kubernetes-worker.config.created')
restart_unit_services()
update_kubelet_status()
apply_node_labels()
remove_state('kubernetes-worker.restart-needed')
@when('cni.connected')
@when_not('cni.configured')
def configure_cni(cni):
''' Set worker configuration on the CNI relation. This lets the CNI
subordinate know that we're the worker so it can respond accordingly. '''
cni.set_config(is_master=False, kubeconfig_path=kubeconfig_path)
@when('config.changed.ingress')
def toggle_ingress_state():
''' Ingress is a toggled state. Remove ingress.available if set when
toggled '''
remove_state('kubernetes-worker.ingress.available')
@when('docker.sdn.configured')
def sdn_changed():
'''The Software Defined Network changed on the container so restart the
kubernetes services.'''
restart_unit_services()
update_kubelet_status()
remove_state('docker.sdn.configured')
@when('kubernetes-worker.config.created')
@when_not('kubernetes-worker.ingress.available')
def render_and_launch_ingress():
''' If configuration has ingress RC enabled, launch the ingress load
balancer and default http backend. Otherwise attempt deletion. '''
config = hookenv.config()
# If ingress is enabled, launch the ingress controller
if config.get('ingress'):
launch_default_ingress_controller()
else:
hookenv.log('Deleting the http backend and ingress.')
kubectl_manifest('delete',
'/root/cdk/addons/default-http-backend.yaml')
kubectl_manifest('delete',
'/root/cdk/addons/ingress-replication-controller.yaml') # noqa
hookenv.close_port(80)
hookenv.close_port(443)
@when('kubernetes-worker.ingress.available')
def scale_ingress_controller():
''' Scale the number of ingress controller replicas to match the number of
nodes. '''
try:
output = kubectl('get', 'nodes', '-o', 'name')
count = len(output.splitlines())
kubectl('scale', '--replicas=%d' % count, 'rc/nginx-ingress-controller') # noqa
except CalledProcessError:
hookenv.log('Failed to scale ingress controllers. Will attempt again next update.') # noqa
@when('config.changed.labels', 'kubernetes-worker.config.created')
def apply_node_labels():
''' Parse the labels configuration option and apply the labels to the node.
'''
# scrub and try to format an array from the configuration option
config = hookenv.config()
user_labels = _parse_labels(config.get('labels'))
# For diffing sake, iterate the previous label set
if config.previous('labels'):
previous_labels = _parse_labels(config.previous('labels'))
hookenv.log('previous labels: {}'.format(previous_labels))
else:
# this handles first time run if there is no previous labels config
previous_labels = _parse_labels("")
# Calculate label removal
for label in previous_labels:
if label not in user_labels:
hookenv.log('Deleting node label {}'.format(label))
_apply_node_label(label, delete=True)
# if the label is in user labels we do nothing here, it will get set
# during the atomic update below.
# Atomically set a label
for label in user_labels:
_apply_node_label(label, overwrite=True)
def arch():
'''Return the package architecture as a string. Raise an exception if the
architecture is not supported by kubernetes.'''
# Get the package architecture for this system.
architecture = check_output(['dpkg', '--print-architecture']).rstrip()
# Convert the binary result into a string.
architecture = architecture.decode('utf-8')
return architecture
def create_config(server, creds):
'''Create a kubernetes configuration for the worker unit.'''
# Get the options from the tls-client layer.
layer_options = layer.options('tls-client')
# Get all the paths to the tls information required for kubeconfig.
ca = layer_options.get('ca_certificate_path')
# Create kubernetes configuration in the default location for ubuntu.
create_kubeconfig('/home/ubuntu/.kube/config', server, ca,
token=creds['client_token'], user='ubuntu')
# Make the config dir readable by the ubuntu users so juju scp works.
cmd = ['chown', '-R', 'ubuntu:ubuntu', '/home/ubuntu/.kube']
check_call(cmd)
# Create kubernetes configuration in the default location for root.
create_kubeconfig('/root/.kube/config', server, ca,
token=creds['client_token'], user='root')
# Create kubernetes configuration for kubelet, and kube-proxy services.
create_kubeconfig(kubeconfig_path, server, ca,
token=creds['kubelet_token'], user='kubelet')
def configure_worker_services(api_servers, dns, cluster_cidr):
''' Add remaining flags for the worker services and configure snaps to use
them '''
layer_options = layer.options('tls-client')
ca_cert_path = layer_options.get('ca_certificate_path')
server_cert_path = layer_options.get('server_certificate_path')
server_key_path = layer_options.get('server_key_path')
kubelet_opts = FlagManager('kubelet')
kubelet_opts.add('require-kubeconfig', 'true')
kubelet_opts.add('kubeconfig', kubeconfig_path)
kubelet_opts.add('network-plugin', 'cni')
kubelet_opts.add('v', '0')
kubelet_opts.add('address', '0.0.0.0')
kubelet_opts.add('port', '10250')
kubelet_opts.add('cluster-dns', dns['sdn-ip'])
kubelet_opts.add('cluster-domain', dns['domain'])
kubelet_opts.add('anonymous-auth', 'false')
kubelet_opts.add('client-ca-file', ca_cert_path)
kubelet_opts.add('tls-cert-file', server_cert_path)
kubelet_opts.add('tls-private-key-file', server_key_path)
kubelet_opts.add('logtostderr', 'true')
kube_proxy_opts = FlagManager('kube-proxy')
kube_proxy_opts.add('cluster-cidr', cluster_cidr)
kube_proxy_opts.add('kubeconfig', kubeconfig_path)
kube_proxy_opts.add('logtostderr', 'true')
kube_proxy_opts.add('v', '0')
kube_proxy_opts.add('master', random.choice(api_servers), strict=True)
if b'lxc' in check_output('virt-what', shell=True):
kube_proxy_opts.add('conntrack-max-per-core', '0')
cmd = ['snap', 'set', 'kubelet'] + kubelet_opts.to_s().split(' ')
check_call(cmd)
cmd = ['snap', 'set', 'kube-proxy'] + kube_proxy_opts.to_s().split(' ')
check_call(cmd)
def create_kubeconfig(kubeconfig, server, ca, key=None, certificate=None,
user='ubuntu', context='juju-context',
cluster='juju-cluster', password=None, token=None):
'''Create a configuration for Kubernetes based on path using the supplied
arguments for values of the Kubernetes server, CA, key, certificate, user
context and cluster.'''
if not key and not certificate and not password and not token:
raise ValueError('Missing authentication mechanism.')
# token and password are mutually exclusive. Error early if both are
# present. The developer has requested an impossible situation.
# see: kubectl config set-credentials --help
if token and password:
raise ValueError('Token and Password are mutually exclusive.')
# Create the config file with the address of the master server.
cmd = 'kubectl config --kubeconfig={0} set-cluster {1} ' \
'--server={2} --certificate-authority={3} --embed-certs=true'
check_call(split(cmd.format(kubeconfig, cluster, server, ca)))
# Delete old users
cmd = 'kubectl config --kubeconfig={0} unset users'
check_call(split(cmd.format(kubeconfig)))
# Create the credentials using the client flags.
cmd = 'kubectl config --kubeconfig={0} ' \
'set-credentials {1} '.format(kubeconfig, user)
if key and certificate:
cmd = '{0} --client-key={1} --client-certificate={2} '\
'--embed-certs=true'.format(cmd, key, certificate)
if password:
cmd = "{0} --username={1} --password={2}".format(cmd, user, password)
# This is mutually exclusive from password. They will not work together.
if token:
cmd = "{0} --token={1}".format(cmd, token)
check_call(split(cmd))
# Create a default context with the cluster.
cmd = 'kubectl config --kubeconfig={0} set-context {1} ' \
'--cluster={2} --user={3}'
check_call(split(cmd.format(kubeconfig, context, cluster, user)))
# Make the config use this new context.
cmd = 'kubectl config --kubeconfig={0} use-context {1}'
check_call(split(cmd.format(kubeconfig, context)))
def launch_default_ingress_controller():
''' Launch the Kubernetes ingress controller & default backend (404) '''
context = {}
context['arch'] = arch()
addon_path = '/root/cdk/addons/{}'
# Render the default http backend (404) replicationcontroller manifest
manifest = addon_path.format('default-http-backend.yaml')
render('default-http-backend.yaml', manifest, context)
hookenv.log('Creating the default http backend.')
try:
kubectl('apply', '-f', manifest)
except CalledProcessError as e:
hookenv.log(e)
hookenv.log('Failed to create default-http-backend. Will attempt again next update.') # noqa
hookenv.close_port(80)
hookenv.close_port(443)
return
# Render the ingress replication controller manifest
manifest = addon_path.format('ingress-replication-controller.yaml')
render('ingress-replication-controller.yaml', manifest, context)
hookenv.log('Creating the ingress replication controller.')
try:
kubectl('apply', '-f', manifest)
except CalledProcessError as e:
hookenv.log(e)
hookenv.log('Failed to create ingress controller. Will attempt again next update.') # noqa
hookenv.close_port(80)
hookenv.close_port(443)
return
set_state('kubernetes-worker.ingress.available')
hookenv.open_port(80)
hookenv.open_port(443)
def restart_unit_services():
'''Restart worker services.'''
hookenv.log('Restarting kubelet and kube-proxy.')
services = ['kube-proxy', 'kubelet']
for service in services:
service_restart('snap.%s.daemon' % service)
def get_kube_api_servers(kube_api):
'''Return the kubernetes api server address and port for this
relationship.'''
hosts = []
# Iterate over every service from the relation object.
for service in kube_api.services():
for unit in service['hosts']:
hosts.append('https://{0}:{1}'.format(unit['hostname'],
unit['port']))
return hosts
def kubectl(*args):
''' Run a kubectl cli command with a config file. Returns stdout and throws
an error if the command fails. '''
command = ['kubectl', '--kubeconfig=' + kubeconfig_path] + list(args)
hookenv.log('Executing {}'.format(command))
return check_output(command)
def kubectl_success(*args):
''' Runs kubectl with the given args. Returns True if succesful, False if
not. '''
try:
kubectl(*args)
return True
except CalledProcessError:
return False
def kubectl_manifest(operation, manifest):
''' Wrap the kubectl creation command when using filepath resources
:param operation - one of get, create, delete, replace
:param manifest - filepath to the manifest
'''
# Deletions are a special case
if operation == 'delete':
# Ensure we immediately remove requested resources with --now
return kubectl_success(operation, '-f', manifest, '--now')
else:
# Guard against an error re-creating the same manifest multiple times
if operation == 'create':
# If we already have the definition, its probably safe to assume
# creation was true.
if kubectl_success('get', '-f', manifest):
hookenv.log('Skipping definition for {}'.format(manifest))
return True
# Execute the requested command that did not match any of the special
# cases above
return kubectl_success(operation, '-f', manifest)
@when('nrpe-external-master.available')
@when_not('nrpe-external-master.initial-config')
def initial_nrpe_config(nagios=None):
set_state('nrpe-external-master.initial-config')
update_nrpe_config(nagios)
@when('kubernetes-worker.config.created')
@when('nrpe-external-master.available')
@when_any('config.changed.nagios_context',
'config.changed.nagios_servicegroups')
def update_nrpe_config(unused=None):
services = ('snap.kubelet.daemon', 'snap.kube-proxy.daemon')
hostname = nrpe.get_nagios_hostname()
current_unit = nrpe.get_nagios_unit_name()
nrpe_setup = nrpe.NRPE(hostname=hostname)
nrpe.add_init_service_checks(nrpe_setup, services, current_unit)
nrpe_setup.write()
@when_not('nrpe-external-master.available')
@when('nrpe-external-master.initial-config')
def remove_nrpe_config(nagios=None):
remove_state('nrpe-external-master.initial-config')
# List of systemd services for which the checks will be removed
services = ('snap.kubelet.daemon', 'snap.kube-proxy.daemon')
# The current nrpe-external-master interface doesn't handle a lot of logic,
# use the charm-helpers code for now.
hostname = nrpe.get_nagios_hostname()
nrpe_setup = nrpe.NRPE(hostname=hostname)
for service in services:
nrpe_setup.remove_check(shortname=service)
def set_privileged():
"""Update the allow-privileged flag for kubelet.
"""
privileged = hookenv.config('allow-privileged')
if privileged == 'auto':
gpu_enabled = is_state('kubernetes-worker.gpu.enabled')
privileged = 'true' if gpu_enabled else 'false'
flag = 'allow-privileged'
hookenv.log('Setting {}={}'.format(flag, privileged))
kubelet_opts = FlagManager('kubelet')
kubelet_opts.add(flag, privileged)
if privileged == 'true':
set_state('kubernetes-worker.privileged')
else:
remove_state('kubernetes-worker.privileged')
@when('config.changed.allow-privileged')
@when('kubernetes-worker.config.created')
def on_config_allow_privileged_change():
"""React to changed 'allow-privileged' config value.
"""
set_state('kubernetes-worker.restart-needed')
remove_state('config.changed.allow-privileged')
@when('cuda.installed')
@when('kubernetes-worker.config.created')
@when_not('kubernetes-worker.gpu.enabled')
def enable_gpu():
"""Enable GPU usage on this node.
"""
config = hookenv.config()
if config['allow-privileged'] == "false":
hookenv.status_set(
'active',
'GPUs available. Set allow-privileged="auto" to enable.'
)
return
hookenv.log('Enabling gpu mode')
try:
# Not sure why this is necessary, but if you don't run this, k8s will
# think that the node has 0 gpus (as shown by the output of
# `kubectl get nodes -o yaml`
check_call(['nvidia-smi'])
except CalledProcessError as cpe:
hookenv.log('Unable to communicate with the NVIDIA driver.')
hookenv.log(cpe)
return
kubelet_opts = FlagManager('kubelet')
if get_version('kubelet') < (1, 6):
hookenv.log('Adding --experimental-nvidia-gpus=1 to kubelet')
kubelet_opts.add('experimental-nvidia-gpus', '1')
else:
hookenv.log('Adding --feature-gates=Accelerators=true to kubelet')
kubelet_opts.add('feature-gates', 'Accelerators=true')
# Apply node labels
_apply_node_label('gpu=true', overwrite=True)
_apply_node_label('cuda=true', overwrite=True)
set_state('kubernetes-worker.gpu.enabled')
set_state('kubernetes-worker.restart-needed')
@when('kubernetes-worker.gpu.enabled')
@when_not('kubernetes-worker.privileged')
@when_not('kubernetes-worker.restart-needed')
def disable_gpu():
"""Disable GPU usage on this node.
This handler fires when we're running in gpu mode, and then the operator
sets allow-privileged="false". Since we can no longer run privileged
containers, we need to disable gpu mode.
"""
hookenv.log('Disabling gpu mode')
kubelet_opts = FlagManager('kubelet')
if get_version('kubelet') < (1, 6):
kubelet_opts.destroy('experimental-nvidia-gpus')
else:
kubelet_opts.remove('feature-gates', 'Accelerators=true')
# Remove node labels
_apply_node_label('gpu', delete=True)
_apply_node_label('cuda', delete=True)
remove_state('kubernetes-worker.gpu.enabled')
set_state('kubernetes-worker.restart-needed')
@when('kubernetes-worker.gpu.enabled')
@when('kube-control.connected')
def notify_master_gpu_enabled(kube_control):
"""Notify kubernetes-master that we're gpu-enabled.
"""
kube_control.set_gpu(True)
@when_not('kubernetes-worker.gpu.enabled')
@when('kube-control.connected')
def notify_master_gpu_not_enabled(kube_control):
"""Notify kubernetes-master that we're not gpu-enabled.
"""
kube_control.set_gpu(False)
@when('kube-control.connected')
def request_kubelet_and_proxy_credentials(kube_control):
""" Request kubelet node authorization with a well formed kubelet user.
This also implies that we are requesting kube-proxy auth. """
# The kube-cotrol interface is created to support RBAC.
# At this point we might as well do the right thing and return the hostname
# even if it will only be used when we enable RBAC
nodeuser = 'system:node:{}'.format(gethostname())
kube_control.set_auth_request(nodeuser)
@when('kube-control.auth.available')
def catch_change_in_creds(kube_control):
"""Request a service restart in case credential updates were detected."""
creds = kube_control.get_auth_credentials()
if data_changed('kube-control.creds', creds):
set_state('kubernetes-worker.restart-needed')
@when_not('kube-control.connected')
def missing_kube_control():
"""Inform the operator they need to add the kube-control relation.
If deploying via bundle this won't happen, but if operator is upgrading a
a charm in a deployment that pre-dates the kube-control relation, it'll be
missing.
"""
hookenv.status_set(
'blocked',
'Relate {}:kube-control kubernetes-master:kube-control'.format(
hookenv.service_name()))
def _systemctl_is_active(application):
''' Poll systemctl to determine if the application is running '''
cmd = ['systemctl', 'is-active', application]
try:
raw = check_output(cmd)
return b'active' in raw
except Exception:
return False
class ApplyNodeLabelFailed(Exception):
pass
def _apply_node_label(label, delete=False, overwrite=False):
''' Invoke kubectl to apply node label changes '''
hostname = gethostname()
# TODO: Make this part of the kubectl calls instead of a special string
cmd_base = 'kubectl --kubeconfig={0} label node {1} {2}'
if delete is True:
label_key = label.split('=')[0]
cmd = cmd_base.format(kubeconfig_path, hostname, label_key)
cmd = cmd + '-'
else:
cmd = cmd_base.format(kubeconfig_path, hostname, label)
if overwrite:
cmd = '{} --overwrite'.format(cmd)
cmd = cmd.split()
deadline = time.time() + 60
while time.time() < deadline:
code = subprocess.call(cmd)
if code == 0:
break
hookenv.log('Failed to apply label %s, exit code %d. Will retry.' % (
label, code))
time.sleep(1)
else:
msg = 'Failed to apply label %s' % label
raise ApplyNodeLabelFailed(msg)
def _parse_labels(labels):
''' Parse labels from a key=value string separated by space.'''
label_array = labels.split(' ')
sanitized_labels = []
for item in label_array:
if '=' in item:
sanitized_labels.append(item)
else:
hookenv.log('Skipping malformed option: {}'.format(item))
return sanitized_labels