def test_service_cache_invalidation_true(self):
jsons = self._load_json_array(
['service_cache_events1.json', 'service_cache_services1.json', 'service_cache_events2.json'])
with patch.object(self.kube, 'retrieve_json_auth', side_effect=jsons):
mapper = PodServiceMapper(self.kube)
mapper._fill_services_cache()
mapper.check_services_cache_freshness()
self.assertEqual(True, mapper._service_cache_invalidated)
def test_service_cache_invalidation_true(self):
jsons = self._load_json_array([
'service_cache_events1.json', 'service_cache_services1.json',
'service_cache_events2.json'
])
with patch.object(self.kube, 'retrieve_json_auth', side_effect=jsons):
mapper = PodServiceMapper(self.kube)
mapper._fill_services_cache()
mapper.check_services_cache_freshness()
self.assertEqual(True, mapper._service_cache_invalidated)
class KubeUtil:
__metaclass__ = Singleton
DEFAULT_METHOD = 'http'
KUBELET_HEALTH_PATH = '/healthz'
MACHINE_INFO_PATH = '/api/v1.3/machine/'
METRICS_PATH = '/api/v1.3/subcontainers/'
PODS_LIST_PATH = '/pods/'
DEFAULT_CADVISOR_PORT = 4194
DEFAULT_HTTP_KUBELET_PORT = 10255
DEFAULT_HTTPS_KUBELET_PORT = 10250
DEFAULT_MASTER_PORT = 8080
DEFAULT_MASTER_NAME = 'kubernetes' # DNS name to reach the master from a pod.
DEFAULT_LABEL_PREFIX = 'kube_'
CA_CRT_PATH = '/var/run/secrets/kubernetes.io/serviceaccount/ca.crt'
AUTH_TOKEN_PATH = '/var/run/secrets/kubernetes.io/serviceaccount/token'
POD_NAME_LABEL = "io.kubernetes.pod.name"
NAMESPACE_LABEL = "io.kubernetes.pod.namespace"
def __init__(self, instance=None):
self.docker_util = DockerUtil()
if instance is None:
try:
config_file_path = get_conf_path(KUBERNETES_CHECK_NAME)
check_config = check_yaml(config_file_path)
instance = check_config['instances'][0]
# kubernetes.yaml was not found
except IOError as ex:
log.error(ex.message)
instance = {}
except Exception:
log.error(
'Kubernetes configuration file is invalid. '
'Trying connecting to kubelet with default settings anyway...'
)
instance = {}
self.method = instance.get('method', KubeUtil.DEFAULT_METHOD)
self._node_ip = self._node_name = None # lazy evaluation
self.host_name = os.environ.get('HOSTNAME')
self.tls_settings = self._init_tls_settings(instance)
# apiserver
self.kubernetes_api_url = 'https://%s/api/v1' % (
os.environ.get('KUBERNETES_SERVICE_HOST')
or self.DEFAULT_MASTER_NAME)
# kubelet
try:
self.kubelet_api_url = self._locate_kubelet(instance)
if not self.kubelet_api_url:
raise Exception(
"Couldn't find a method to connect to kubelet.")
except Exception as ex:
log.error(
"Kubernetes check exiting, cannot run without access to kubelet."
)
raise ex
# Service mapping helper class
self._service_mapper = PodServiceMapper(self)
self.kubelet_host = self.kubelet_api_url.split(':')[1].lstrip('/')
self.pods_list_url = urljoin(self.kubelet_api_url,
KubeUtil.PODS_LIST_PATH)
self.kube_health_url = urljoin(self.kubelet_api_url,
KubeUtil.KUBELET_HEALTH_PATH)
self.kube_label_prefix = instance.get('label_to_tag_prefix',
KubeUtil.DEFAULT_LABEL_PREFIX)
# cadvisor
self.cadvisor_port = instance.get('port',
KubeUtil.DEFAULT_CADVISOR_PORT)
self.cadvisor_url = '%s://%s:%d' % (self.method, self.kubelet_host,
self.cadvisor_port)
self.metrics_url = urljoin(self.cadvisor_url, KubeUtil.METRICS_PATH)
self.machine_info_url = urljoin(self.cadvisor_url,
KubeUtil.MACHINE_INFO_PATH)
# keep track of the latest k8s event we collected and posted
# default value is 0 but TTL for k8s events is one hour anyways
self.last_event_collection_ts = 0
def _init_tls_settings(self, instance):
"""
Initialize TLS settings for connection to apiserver and kubelet.
"""
tls_settings = {}
# apiserver
client_crt = instance.get('apiserver_client_crt')
client_key = instance.get('apiserver_client_key')
apiserver_cacert = instance.get('apiserver_ca_cert')
if client_crt and client_key and os.path.exists(
client_crt) and os.path.exists(client_key):
tls_settings['apiserver_client_cert'] = (client_crt, client_key)
if apiserver_cacert and os.path.exists(apiserver_cacert):
tls_settings['apiserver_cacert'] = apiserver_cacert
token = self.get_auth_token()
if token:
tls_settings['bearer_token'] = token
# kubelet
kubelet_client_crt = instance.get('kubelet_client_crt')
kubelet_client_key = instance.get('kubelet_client_key')
if kubelet_client_crt and kubelet_client_key and os.path.exists(
kubelet_client_crt) and os.path.exists(kubelet_client_key):
tls_settings['kubelet_client_cert'] = (kubelet_client_crt,
kubelet_client_key)
cert = instance.get('kubelet_cert')
if cert:
tls_settings['kubelet_verify'] = cert
else:
tls_settings['kubelet_verify'] = instance.get(
'kubelet_tls_verify', DEFAULT_TLS_VERIFY)
return tls_settings
def _locate_kubelet(self, instance):
"""
Kubelet may or may not accept un-authenticated http requests.
If it doesn't we need to use its HTTPS API that may or may not
require auth.
"""
host = os.environ.get('KUBERNETES_KUBELET_HOST') or instance.get(
"host")
if not host:
# if no hostname was provided, use the docker hostname if cert
# validation is not required, the kubernetes hostname otherwise.
docker_hostname = self.docker_util.get_hostname(
should_resolve=True)
if self.tls_settings.get('kubelet_verify'):
try:
k8s_hostname = self.get_node_hostname(docker_hostname)
host = k8s_hostname or docker_hostname
except Exception as ex:
log.error(str(ex))
host = docker_hostname
else:
host = docker_hostname
try:
# check if the no-auth endpoint is enabled
port = instance.get('kubelet_port',
KubeUtil.DEFAULT_HTTP_KUBELET_PORT)
no_auth_url = 'http://%s:%s' % (host, port)
test_url = urljoin(no_auth_url, KubeUtil.KUBELET_HEALTH_PATH)
self.perform_kubelet_query(test_url)
return no_auth_url
except Exception:
log.debug(
"Couldn't query kubelet over HTTP, assuming it's not in no_auth mode."
)
port = instance.get('kubelet_port',
KubeUtil.DEFAULT_HTTPS_KUBELET_PORT)
https_url = 'https://%s:%s' % (host, port)
test_url = urljoin(https_url, KubeUtil.KUBELET_HEALTH_PATH)
self.perform_kubelet_query(test_url)
return https_url
def get_node_hostname(self, host):
"""
Query the API server for the kubernetes hostname of the node
using the docker hostname as a filter.
"""
node_filter = {'labelSelector': 'kubernetes.io/hostname=%s' % host}
node = self.retrieve_json_auth(self.kubernetes_api_url +
'/nodes?%s' % urlencode(node_filter))
if len(node['items']) != 1:
log.error(
'Error while getting node hostname: expected 1 node, got %s.' %
len(node['items']))
else:
addresses = (node or {}).get('items',
[{}])[0].get('status',
{}).get('addresses', [])
for address in addresses:
if address.get('type') == 'Hostname':
return address['address']
return None
def get_kube_pod_tags(self, excluded_keys=None):
"""
Gets pods' labels as tags + creator and service tags.
Returns a dict{namespace/podname: [tags]}
"""
pods = self.retrieve_pods_list()
return self.extract_kube_pod_tags(pods, excluded_keys=excluded_keys)
def extract_kube_pod_tags(self,
pods_list,
excluded_keys=None,
label_prefix=None):
"""
Extract labels + creator and service tags from a list of
pods coming from the kubelet API.
:param excluded_keys: labels to skip
:param label_prefix: prefix for label->tag conversion, None defaults
to the configuration option label_to_tag_prefix
Returns a dict{namespace/podname: [tags]}
"""
excluded_keys = excluded_keys or []
kube_labels = defaultdict(list)
pod_items = pods_list.get("items") or []
label_prefix = label_prefix or self.kube_label_prefix
for pod in pod_items:
metadata = pod.get("metadata", {})
name = metadata.get("name")
namespace = metadata.get("namespace")
labels = metadata.get("labels", {})
if name and namespace:
key = "%s/%s" % (namespace, name)
# Extract creator tags
podtags = self.get_pod_creator_tags(metadata)
# Extract services tags
for service in self.match_services_for_pod(metadata):
if service is not None:
podtags.append(u'kube_service:%s' % service)
# Extract labels
for k, v in labels.iteritems():
if k in excluded_keys:
continue
podtags.append(u"%s%s:%s" % (label_prefix, k, v))
kube_labels[key] = podtags
return kube_labels
def retrieve_pods_list(self):
"""
Retrieve the list of pods for this cluster querying the kubelet API.
TODO: the list of pods could be cached with some policy to be decided.
"""
return self.perform_kubelet_query(self.pods_list_url).json()
def retrieve_machine_info(self):
"""
Retrieve machine info from Cadvisor.
"""
return retrieve_json(self.machine_info_url)
def retrieve_metrics(self):
"""
Retrieve metrics from Cadvisor.
"""
return retrieve_json(self.metrics_url)
def get_deployment_for_replicaset(self, rs_name):
"""
Get the deployment name for a given replicaset name
For now, the rs name's first part always is the deployment's name, see
https://github.com/kubernetes/kubernetes/blob/release-1.6/pkg/controller/deployment/sync.go#L299
But it might change in a future k8s version. The other way to match RS and deployments is
to parse and cache /apis/extensions/v1beta1/replicasets, mirroring PodServiceMapper
"""
end = rs_name.rfind("-")
if end > 0 and rs_name[end + 1:].isdigit():
return rs_name[0:end]
else:
return None
def perform_kubelet_query(self, url, verbose=True, timeout=10):
"""
Perform and return a GET request against kubelet. Support auth and TLS validation.
"""
tls_context = self.tls_settings
headers = None
cert = tls_context.get('kubelet_client_cert')
verify = tls_context.get('kubelet_verify', DEFAULT_TLS_VERIFY)
# if cert-based auth is enabled, don't use the token.
if not cert and url.lower().startswith('https'):
headers = {
'Authorization': 'Bearer {}'.format(self.get_auth_token())
}
return requests.get(url,
timeout=timeout,
verify=verify,
cert=cert,
headers=headers,
params={'verbose': verbose})
def retrieve_json_auth(self, url, timeout=10, verify=None, params=None):
"""
Kubernetes API requires authentication using a token available in
every pod, or with a client X509 cert/key pair.
We authenticate using the service account token by default
and replace this behavior with cert authentication if the user provided
a cert/key pair in the instance.
We try to verify the server TLS cert if the public cert is available.
"""
verify = self.tls_settings.get('apiserver_cacert')
if not verify:
verify = self.CA_CRT_PATH if os.path.exists(
self.CA_CRT_PATH) else False
log.debug('tls validation: {}'.format(verify))
cert = self.tls_settings.get('apiserver_client_cert')
bearer_token = self.tls_settings.get(
'bearer_token') if not cert else None
headers = {
'Authorization': 'Bearer {}'.format(bearer_token)
} if bearer_token else None
r = requests.get(url,
timeout=timeout,
headers=headers,
verify=verify,
cert=cert,
params=params)
r.raise_for_status()
return r.json()
def get_node_info(self):
"""
Return the IP address and the hostname of the node where the pod is running.
"""
if None in (self._node_ip, self._node_name):
self._fetch_host_data()
return self._node_ip, self._node_name
def _fetch_host_data(self):
"""
Retrieve host name and IP address from the payload returned by the listing
pods endpoints from kubelet.
The host IP address is different from the default router for the pod.
"""
try:
pod_items = self.retrieve_pods_list().get("items") or []
except Exception as e:
log.warning(
"Unable to retrieve pod list %s. Not fetching host data",
str(e))
return
for pod in pod_items:
metadata = pod.get("metadata", {})
name = metadata.get("name")
if name == self.host_name:
status = pod.get('status', {})
spec = pod.get('spec', {})
# if not found, use an empty string - we use None as "not initialized"
self._node_ip = status.get('hostIP', '')
self._node_name = spec.get('nodeName', '')
break
def extract_event_tags(self, event):
"""
Return a list of tags extracted from an event object
"""
tags = []
if 'reason' in event:
tags.append('reason:%s' % event.get('reason', '').lower())
if 'namespace' in event.get('metadata', {}):
tags.append('namespace:%s' % event['metadata']['namespace'])
if 'host' in event.get('source', {}):
tags.append('node_name:%s' % event['source']['host'])
if 'kind' in event.get('involvedObject', {}):
tags.append('object_type:%s' %
event['involvedObject'].get('kind', '').lower())
return tags
def are_tags_filtered(self, tags):
"""
Because it is a pain to call it from the kubernetes check otherwise.
"""
return self.docker_util.are_tags_filtered(tags)
@classmethod
def get_auth_token(cls):
"""
Return a string containing the authorization token for the pod.
"""
try:
with open(cls.AUTH_TOKEN_PATH) as f:
return f.read()
except IOError as e:
log.error('Unable to read token from {}: {}'.format(
cls.AUTH_TOKEN_PATH, e))
return None
def check_services_cache_freshness(self):
"""
Entry point for sd_docker_backend to check whether to invalidate the cached services
For now, we remove the whole cache as the fill_service_cache logic
doesn't handle partial lookups
We use the event's resourceVersion, as using the service's version wouldn't catch deletion
"""
return self._service_mapper.check_services_cache_freshness()
def match_services_for_pod(self, pod_metadata, refresh=False):
"""
Match the pods labels with services' label selectors to determine the list
of services that point to that pod. Returns an array of service names.
Pass refresh=True if you want to bypass the cached cid->services mapping (after a service change)
"""
s = self._service_mapper.match_services_for_pod(pod_metadata,
refresh,
names=True)
#log.warning("Matches for %s: %s" % (pod_metadata.get('name'), str(s)))
return s
def get_event_retriever(self, namespaces=None, kinds=None):
"""
Returns a KubeEventRetriever object ready for action
"""
return KubeEventRetriever(self, namespaces, kinds)
def match_containers_for_pods(self, pod_uids, podlist=None):
"""
Reads a set of pod uids and returns the set of docker
container ids they manage
podlist should be a recent self.retrieve_pods_list return value,
if not given that method will be called
"""
cids = set()
if not isinstance(pod_uids, set) or len(pod_uids) < 1:
return cids
if podlist is None:
podlist = self.retrieve_pods_list()
for pod in podlist.get('items', {}):
uid = pod.get('metadata', {}).get('uid', None)
if uid in pod_uids:
for container in pod.get('status',
{}).get('containerStatuses', None):
id = container.get('containerID', "")
if id.startswith("docker://"):
cids.add(id[9:])
return cids
def get_pod_creator(self, pod_metadata):
"""
Get the pod's creator from its metadata and returns a
tuple (creator_kind, creator_name)
This allows for consitency across code path
"""
try:
created_by = json.loads(
pod_metadata['annotations']['kubernetes.io/created-by'])
creator_kind = created_by.get('reference', {}).get('kind')
creator_name = created_by.get('reference', {}).get('name')
return (creator_kind, creator_name)
except Exception:
log.debug('Could not parse creator for pod ' +
pod_metadata.get('name', ''))
return (None, None)
def get_pod_creator_tags(self,
pod_metadata,
legacy_rep_controller_tag=False):
"""
Get the pod's creator from its metadata and returns a list of tags
in the form kube_$kind:$name, ready to add to the metrics
"""
try:
tags = []
creator_kind, creator_name = self.get_pod_creator(pod_metadata)
if creator_kind in CREATOR_KIND_TO_TAG and creator_name:
tags.append("%s:%s" %
(CREATOR_KIND_TO_TAG[creator_kind], creator_name))
if creator_kind == 'ReplicaSet':
deployment = self.get_deployment_for_replicaset(
creator_name)
if deployment:
tags.append(
"%s:%s" %
(CREATOR_KIND_TO_TAG['Deployment'], deployment))
if legacy_rep_controller_tag and creator_kind != 'ReplicationController' and creator_name:
tags.append(
'kube_replication_controller:{0}'.format(creator_name))
return tags
except Exception:
log.warning('Could not parse creator tags for pod ' +
pod_metadata.get('name'))
return []
def process_events(self, event_array, podlist=None):
"""
Reads a list of kube events, invalidates caches and and computes a set
of containers impacted by the changes, to refresh service discovery
Pod creation/deletion events are ignored for now, as docker_daemon already
sends container creation/deletion events to SD
Pod->containers matching is done using match_containers_for_pods
"""
try:
pods = set()
if self._service_mapper:
pods.update(self._service_mapper.process_events(event_array))
return self.match_containers_for_pods(pods, podlist)
except Exception as e:
log.warning("Error processing events %s: %s" %
(str(event_array), e))
return set()
