# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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.
"""Kubernetes executor"""
import base64
import hashlib
from queue import Empty
import re
import json
import multiprocessing
from uuid import uuid4
from dateutil import parser
import kubernetes
from kubernetes import watch, client
from kubernetes.client.rest import ApiException
from urllib3.exceptions import HTTPError
from airflow.configuration import conf
from airflow.contrib.kubernetes.pod_launcher import PodLauncher
from airflow.contrib.kubernetes.kube_client import get_kube_client
from airflow.contrib.kubernetes.worker_configuration import WorkerConfiguration
from airflow.executors.base_executor import BaseExecutor
from airflow.executors import Executors
from airflow.models import KubeResourceVersion, KubeWorkerIdentifier, TaskInstance
from airflow.utils.state import State
from airflow.utils.db import provide_session, create_session
from airflow import settings
from airflow.exceptions import AirflowConfigException, AirflowException
from airflow.utils.log.logging_mixin import LoggingMixin
[docs]class KubernetesExecutorConfig:
def __init__(self, image=None, image_pull_policy=None, request_memory=None,
request_cpu=None, limit_memory=None, limit_cpu=None, limit_gpu=None,
gcp_service_account_key=None, node_selectors=None, affinity=None,
annotations=None, volumes=None, volume_mounts=None, tolerations=None, labels=None):
self.image = image
self.image_pull_policy = image_pull_policy
self.request_memory = request_memory
self.request_cpu = request_cpu
self.limit_memory = limit_memory
self.limit_cpu = limit_cpu
self.limit_gpu = limit_gpu
self.gcp_service_account_key = gcp_service_account_key
self.node_selectors = node_selectors
self.affinity = affinity
self.annotations = annotations
self.volumes = volumes
self.volume_mounts = volume_mounts
self.tolerations = tolerations
self.labels = labels or {}
[docs] def __repr__(self):
return "{}(image={}, image_pull_policy={}, request_memory={}, request_cpu={}, " \
"limit_memory={}, limit_cpu={}, limit_gpu={}, gcp_service_account_key={}, " \
"node_selectors={}, affinity={}, annotations={}, volumes={}, " \
"volume_mounts={}, tolerations={}, labels={})" \
.format(KubernetesExecutorConfig.__name__, self.image, self.image_pull_policy,
self.request_memory, self.request_cpu, self.limit_memory,
self.limit_cpu, self.limit_gpu, self.gcp_service_account_key, self.node_selectors,
self.affinity, self.annotations, self.volumes, self.volume_mounts,
self.tolerations, self.labels)
@staticmethod
[docs] def from_dict(obj):
if obj is None:
return KubernetesExecutorConfig()
if not isinstance(obj, dict):
raise TypeError(
'Cannot convert a non-dictionary object into a KubernetesExecutorConfig')
namespaced = obj.get(Executors.KubernetesExecutor, {})
return KubernetesExecutorConfig(
image=namespaced.get('image', None),
image_pull_policy=namespaced.get('image_pull_policy', None),
request_memory=namespaced.get('request_memory', None),
request_cpu=namespaced.get('request_cpu', None),
limit_memory=namespaced.get('limit_memory', None),
limit_cpu=namespaced.get('limit_cpu', None),
limit_gpu=namespaced.get('limit_gpu', None),
gcp_service_account_key=namespaced.get('gcp_service_account_key', None),
node_selectors=namespaced.get('node_selectors', None),
affinity=namespaced.get('affinity', None),
annotations=namespaced.get('annotations', {}),
volumes=namespaced.get('volumes', []),
volume_mounts=namespaced.get('volume_mounts', []),
tolerations=namespaced.get('tolerations', None),
labels=namespaced.get('labels', {}),
)
[docs] def as_dict(self):
return {
'image': self.image,
'image_pull_policy': self.image_pull_policy,
'request_memory': self.request_memory,
'request_cpu': self.request_cpu,
'limit_memory': self.limit_memory,
'limit_cpu': self.limit_cpu,
'limit_gpu': self.limit_gpu,
'gcp_service_account_key': self.gcp_service_account_key,
'node_selectors': self.node_selectors,
'affinity': self.affinity,
'annotations': self.annotations,
'volumes': self.volumes,
'volume_mounts': self.volume_mounts,
'tolerations': self.tolerations,
'labels': self.labels,
}
[docs]class KubeConfig:
"""Configuration for Kubernetes"""
[docs] kubernetes_section = 'kubernetes'
def __init__(self):
configuration_dict = conf.as_dict(display_sensitive=True)
self.core_configuration = configuration_dict['core']
self.kube_secrets = configuration_dict.get('kubernetes_secrets', {})
self.kube_env_vars = configuration_dict.get('kubernetes_environment_variables', {})
self.env_from_configmap_ref = conf.get(self.kubernetes_section,
'env_from_configmap_ref')
self.env_from_secret_ref = conf.get(self.kubernetes_section,
'env_from_secret_ref')
self.airflow_home = settings.AIRFLOW_HOME
self.dags_folder = conf.get(self.core_section, 'dags_folder')
self.parallelism = conf.getint(self.core_section, 'parallelism')
self.worker_container_repository = conf.get(
self.kubernetes_section, 'worker_container_repository')
self.worker_container_tag = conf.get(
self.kubernetes_section, 'worker_container_tag')
self.kube_image = '{}:{}'.format(
self.worker_container_repository, self.worker_container_tag)
self.kube_image_pull_policy = conf.get(
self.kubernetes_section, "worker_container_image_pull_policy"
)
self.kube_node_selectors = configuration_dict.get('kubernetes_node_selectors', {})
self.kube_annotations = configuration_dict.get('kubernetes_annotations', {})
self.kube_labels = configuration_dict.get('kubernetes_labels', {})
self.delete_worker_pods = conf.getboolean(
self.kubernetes_section, 'delete_worker_pods')
self.worker_pods_creation_batch_size = conf.getint(
self.kubernetes_section, 'worker_pods_creation_batch_size')
self.worker_service_account_name = conf.get(
self.kubernetes_section, 'worker_service_account_name')
self.image_pull_secrets = conf.get(self.kubernetes_section, 'image_pull_secrets')
# NOTE: user can build the dags into the docker image directly,
# this will set to True if so
self.dags_in_image = conf.getboolean(self.kubernetes_section, 'dags_in_image')
# Run as user for pod security context
self.worker_run_as_user = self._get_security_context_val('run_as_user')
self.worker_fs_group = self._get_security_context_val('fs_group')
# NOTE: `git_repo` and `git_branch` must be specified together as a pair
# The http URL of the git repository to clone from
self.git_repo = conf.get(self.kubernetes_section, 'git_repo')
# The branch of the repository to be checked out
self.git_branch = conf.get(self.kubernetes_section, 'git_branch')
# Optionally, the directory in the git repository containing the dags
self.git_subpath = conf.get(self.kubernetes_section, 'git_subpath')
# Optionally, the root directory for git operations
self.git_sync_root = conf.get(self.kubernetes_section, 'git_sync_root')
# Optionally, the name at which to publish the checked-out files under --root
self.git_sync_dest = conf.get(self.kubernetes_section, 'git_sync_dest')
# Optionally, if git_dags_folder_mount_point is set the worker will use
# {git_dags_folder_mount_point}/{git_sync_dest}/{git_subpath} as dags_folder
self.git_dags_folder_mount_point = conf.get(self.kubernetes_section,
'git_dags_folder_mount_point')
# Optionally a user may supply a (`git_user` AND `git_password`) OR
# (`git_ssh_key_secret_name` AND `git_ssh_key_secret_key`) for private repositories
self.git_user = conf.get(self.kubernetes_section, 'git_user')
self.git_password = conf.get(self.kubernetes_section, 'git_password')
self.git_ssh_key_secret_name = conf.get(self.kubernetes_section, 'git_ssh_key_secret_name')
self.git_ssh_known_hosts_configmap_name = conf.get(self.kubernetes_section,
'git_ssh_known_hosts_configmap_name')
self.git_sync_credentials_secret = conf.get(self.kubernetes_section,
'git_sync_credentials_secret')
# NOTE: The user may optionally use a volume claim to mount a PV containing
# DAGs directly
self.dags_volume_claim = conf.get(self.kubernetes_section, 'dags_volume_claim')
# This prop may optionally be set for PV Claims and is used to write logs
self.logs_volume_claim = conf.get(self.kubernetes_section, 'logs_volume_claim')
# This prop may optionally be set for PV Claims and is used to locate DAGs
# on a SubPath
self.dags_volume_subpath = conf.get(
self.kubernetes_section, 'dags_volume_subpath')
# This prop may optionally be set for PV Claims and is used to locate logs
# on a SubPath
self.logs_volume_subpath = conf.get(
self.kubernetes_section, 'logs_volume_subpath')
# Optionally, hostPath volume containing DAGs
self.dags_volume_host = conf.get(self.kubernetes_section, 'dags_volume_host')
# Optionally, write logs to a hostPath Volume
self.logs_volume_host = conf.get(self.kubernetes_section, 'logs_volume_host')
# This prop may optionally be set for PV Claims and is used to write logs
self.base_log_folder = conf.get(self.core_section, 'base_log_folder')
# The Kubernetes Namespace in which the Scheduler and Webserver reside. Note
# that if your
# cluster has RBAC enabled, your scheduler may need service account permissions to
# create, watch, get, and delete pods in this namespace.
self.kube_namespace = conf.get(self.kubernetes_section, 'namespace')
# The Kubernetes Namespace in which pods will be created by the executor. Note
# that if your
# cluster has RBAC enabled, your workers may need service account permissions to
# interact with cluster components.
self.executor_namespace = conf.get(self.kubernetes_section, 'namespace')
# Task secrets managed by KubernetesExecutor.
self.gcp_service_account_keys = conf.get(self.kubernetes_section,
'gcp_service_account_keys')
# If the user is using the git-sync container to clone their repository via git,
# allow them to specify repository, tag, and pod name for the init container.
self.git_sync_container_repository = conf.get(
self.kubernetes_section, 'git_sync_container_repository')
self.git_sync_container_tag = conf.get(
self.kubernetes_section, 'git_sync_container_tag')
self.git_sync_container = '{}:{}'.format(
self.git_sync_container_repository, self.git_sync_container_tag)
self.git_sync_init_container_name = conf.get(
self.kubernetes_section, 'git_sync_init_container_name')
self.git_sync_run_as_user = self._get_security_context_val('git_sync_run_as_user')
# The worker pod may optionally have a valid Airflow config loaded via a
# configmap
self.airflow_configmap = conf.get(self.kubernetes_section, 'airflow_configmap')
affinity_json = conf.get(self.kubernetes_section, 'affinity')
if affinity_json:
self.kube_affinity = json.loads(affinity_json)
else:
self.kube_affinity = None
tolerations_json = conf.get(self.kubernetes_section, 'tolerations')
if tolerations_json:
self.kube_tolerations = json.loads(tolerations_json)
else:
self.kube_tolerations = None
kube_client_request_args = conf.get(self.kubernetes_section, 'kube_client_request_args')
if kube_client_request_args:
self.kube_client_request_args = json.loads(kube_client_request_args)
if self.kube_client_request_args['_request_timeout'] and \
isinstance(self.kube_client_request_args['_request_timeout'], list):
self.kube_client_request_args['_request_timeout'] = \
tuple(self.kube_client_request_args['_request_timeout'])
else:
self.kube_client_request_args = {}
self._validate()
# pod security context items should return integers
# and only return a blank string if contexts are not set.
[docs] def _get_security_context_val(self, scontext):
val = conf.get(self.kubernetes_section, scontext)
if not val:
return 0
else:
return int(val)
[docs] def _validate(self):
# TODO: use XOR for dags_volume_claim and git_dags_folder_mount_point
if not self.dags_volume_claim \
and not self.dags_volume_host \
and not self.dags_in_image \
and (not self.git_repo or not self.git_branch or not self.git_dags_folder_mount_point):
raise AirflowConfigException(
'In kubernetes mode the following must be set in the `kubernetes` '
'config section: `dags_volume_claim` '
'or `dags_volume_host` '
'or `dags_in_image` '
'or `git_repo and git_branch and git_dags_folder_mount_point`')
if self.git_repo \
and (self.git_user or self.git_password) \
and self.git_ssh_key_secret_name:
raise AirflowConfigException(
'In kubernetes mode, using `git_repo` to pull the DAGs: '
'for private repositories, either `git_user` and `git_password` '
'must be set for authentication through user credentials; '
'or `git_ssh_key_secret_name` must be set for authentication '
'through ssh key, but not both')
[docs]class KubernetesJobWatcher(multiprocessing.Process, LoggingMixin):
"""Watches for Kubernetes jobs"""
def __init__(self, namespace, watcher_queue, resource_version, worker_uuid, kube_config):
multiprocessing.Process.__init__(self)
self.namespace = namespace
self.worker_uuid = worker_uuid
self.watcher_queue = watcher_queue
self.resource_version = resource_version
self.kube_config = kube_config
[docs] def run(self):
"""Performs watching"""
kube_client = get_kube_client()
while True:
try:
self.resource_version = self._run(kube_client, self.resource_version,
self.worker_uuid, self.kube_config)
except Exception:
self.log.exception('Unknown error in KubernetesJobWatcher. Failing')
raise
else:
self.log.warning('Watch died gracefully, starting back up with: '
'last resource_version: %s', self.resource_version)
[docs] def _run(self, kube_client, resource_version, worker_uuid, kube_config):
self.log.info(
'Event: and now my watch begins starting at resource_version: %s',
resource_version
)
watcher = watch.Watch()
kwargs = {'label_selector': 'airflow-worker={}'.format(worker_uuid)}
if resource_version:
kwargs['resource_version'] = resource_version
if kube_config.kube_client_request_args:
for key, value in kube_config.kube_client_request_args.items():
kwargs[key] = value
last_resource_version = None
for event in watcher.stream(kube_client.list_namespaced_pod, self.namespace,
**kwargs):
task = event['object']
self.log.info(
'Event: %s had an event of type %s',
task.metadata.name, event['type']
)
if event['type'] == 'ERROR':
return self.process_error(event)
self.process_status(
task.metadata.name, task.status.phase, task.metadata.labels,
task.metadata.resource_version
)
last_resource_version = task.metadata.resource_version
return last_resource_version
[docs] def process_error(self, event):
"""Process error response"""
self.log.error(
'Encountered Error response from k8s list namespaced pod stream => %s',
event
)
raw_object = event['raw_object']
if raw_object['code'] == 410:
self.log.info(
'Kubernetes resource version is too old, must reset to 0 => %s',
(raw_object['message'],)
)
# Return resource version 0
return '0'
raise AirflowException(
'Kubernetes failure for %s with code %s and message: %s' %
(raw_object['reason'], raw_object['code'], raw_object['message'])
)
[docs] def process_status(self, pod_id, status, labels, resource_version):
"""Process status response"""
if status == 'Pending':
self.log.info('Event: %s Pending', pod_id)
elif status == 'Failed':
self.log.info('Event: %s Failed', pod_id)
self.watcher_queue.put((pod_id, State.FAILED, labels, resource_version))
elif status == 'Succeeded':
self.log.info('Event: %s Succeeded', pod_id)
self.watcher_queue.put((pod_id, None, labels, resource_version))
elif status == 'Running':
self.log.info('Event: %s is Running', pod_id)
else:
self.log.warning(
'Event: Invalid state: %s on pod: %s with labels: %s with '
'resource_version: %s', status, pod_id, labels, resource_version
)
[docs]class AirflowKubernetesScheduler(LoggingMixin):
"""Airflow Scheduler for Kubernetes"""
def __init__(self, kube_config, task_queue, result_queue, kube_client, worker_uuid):
self.log.debug("Creating Kubernetes executor")
self.kube_config = kube_config
self.task_queue = task_queue
self.result_queue = result_queue
self.namespace = self.kube_config.kube_namespace
self.log.debug("Kubernetes using namespace %s", self.namespace)
self.kube_client = kube_client
self.launcher = PodLauncher(kube_client=self.kube_client)
self.worker_configuration = WorkerConfiguration(kube_config=self.kube_config)
self._manager = multiprocessing.Manager()
self.watcher_queue = self._manager.Queue()
self.worker_uuid = worker_uuid
self.kube_watcher = self._make_kube_watcher()
[docs] def _make_kube_watcher(self):
resource_version = KubeResourceVersion.get_current_resource_version()
watcher = KubernetesJobWatcher(self.namespace, self.watcher_queue,
resource_version, self.worker_uuid, self.kube_config)
watcher.start()
return watcher
[docs] def _health_check_kube_watcher(self):
if self.kube_watcher.is_alive():
pass
else:
self.log.error(
'Error while health checking kube watcher process. '
'Process died for unknown reasons')
self.kube_watcher = self._make_kube_watcher()
[docs] def run_next(self, next_job):
"""
The run_next command will check the task_queue for any un-run jobs.
It will then create a unique job-id, launch that job in the cluster,
and store relevant info in the current_jobs map so we can track the job's
status
"""
self.log.info('Kubernetes job is %s', str(next_job))
key, command, kube_executor_config = next_job
dag_id, task_id, execution_date, try_number = key
self.log.debug("Kubernetes running for command %s", command)
self.log.debug("Kubernetes launching image %s", self.kube_config.kube_image)
pod = self.worker_configuration.make_pod(
namespace=self.namespace, worker_uuid=self.worker_uuid,
pod_id=self._create_pod_id(dag_id, task_id),
dag_id=self._make_safe_label_value(dag_id),
task_id=self._make_safe_label_value(task_id),
try_number=try_number,
execution_date=self._datetime_to_label_safe_datestring(execution_date),
airflow_command=command, kube_executor_config=kube_executor_config
)
# the watcher will monitor pods, so we do not block.
self.launcher.run_pod_async(pod, **self.kube_config.kube_client_request_args)
self.log.debug("Kubernetes Job created!")
[docs] def delete_pod(self, pod_id):
"""Deletes POD"""
try:
self.kube_client.delete_namespaced_pod(
pod_id, self.namespace, body=client.V1DeleteOptions(),
**self.kube_config.kube_client_request_args)
except ApiException as e:
# If the pod is already deleted
if e.status != 404:
raise
[docs] def sync(self):
"""
The sync function checks the status of all currently running kubernetes jobs.
If a job is completed, it's status is placed in the result queue to
be sent back to the scheduler.
:return:
"""
self._health_check_kube_watcher()
while True:
try:
task = self.watcher_queue.get_nowait()
try:
self.process_watcher_task(task)
finally:
self.watcher_queue.task_done()
except Empty:
break
[docs] def process_watcher_task(self, task):
"""Process the task by watcher."""
pod_id, state, labels, resource_version = task
self.log.info(
'Attempting to finish pod; pod_id: %s; state: %s; labels: %s',
pod_id, state, labels
)
key = self._labels_to_key(labels=labels)
if key:
self.log.debug('finishing job %s - %s (%s)', key, state, pod_id)
self.result_queue.put((key, state, pod_id, resource_version))
@staticmethod
[docs] def _strip_unsafe_kubernetes_special_chars(string):
"""
Kubernetes only supports lowercase alphanumeric characters and "-" and "." in
the pod name
However, there are special rules about how "-" and "." can be used so let's
only keep
alphanumeric chars see here for detail:
https://kubernetes.io/docs/concepts/overview/working-with-objects/names/
:param string: The requested Pod name
:return: ``str`` Pod name stripped of any unsafe characters
"""
return ''.join(ch.lower() for ind, ch in enumerate(string) if ch.isalnum())
@staticmethod
[docs] def _make_safe_pod_id(safe_dag_id, safe_task_id, safe_uuid):
"""
Kubernetes pod names must be <= 253 chars and must pass the following regex for
validation
"^[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$"
:param safe_dag_id: a dag_id with only alphanumeric characters
:param safe_task_id: a task_id with only alphanumeric characters
:param random_uuid: a uuid
:return: ``str`` valid Pod name of appropriate length
"""
safe_key = safe_dag_id + safe_task_id
safe_pod_id = safe_key[:MAX_POD_ID_LEN - len(safe_uuid) - 1] + "-" + safe_uuid
return safe_pod_id
@staticmethod
[docs] def _make_safe_label_value(string):
"""
Valid label values must be 63 characters or less and must be empty or begin and
end with an alphanumeric character ([a-z0-9A-Z]) with dashes (-), underscores (_),
dots (.), and alphanumerics between.
If the label value is then greater than 63 chars once made safe, or differs in any
way from the original value sent to this function, then we need to truncate to
53chars, and append it with a unique hash.
"""
safe_label = re.sub(r'^[^a-z0-9A-Z]*|[^a-zA-Z0-9_\-\.]|[^a-z0-9A-Z]*$', '', string)
if len(safe_label) > MAX_LABEL_LEN or string != safe_label:
safe_hash = hashlib.md5(string.encode()).hexdigest()[:9]
safe_label = safe_label[:MAX_LABEL_LEN - len(safe_hash) - 1] + "-" + safe_hash
return safe_label
@staticmethod
[docs] def _create_pod_id(dag_id, task_id):
safe_dag_id = AirflowKubernetesScheduler._strip_unsafe_kubernetes_special_chars(
dag_id)
safe_task_id = AirflowKubernetesScheduler._strip_unsafe_kubernetes_special_chars(
task_id)
safe_uuid = AirflowKubernetesScheduler._strip_unsafe_kubernetes_special_chars(
uuid4().hex)
return AirflowKubernetesScheduler._make_safe_pod_id(safe_dag_id, safe_task_id,
safe_uuid)
@staticmethod
[docs] def _label_safe_datestring_to_datetime(string):
"""
Kubernetes doesn't permit ":" in labels. ISO datetime format uses ":" but not
"_", let's
replace ":" with "_"
:param string: str
:return: datetime.datetime object
"""
return parser.parse(string.replace('_plus_', '+').replace("_", ":"))
@staticmethod
[docs] def _datetime_to_label_safe_datestring(datetime_obj):
"""
Kubernetes doesn't like ":" in labels, since ISO datetime format uses ":" but
not "_" let's
replace ":" with "_"
:param datetime_obj: datetime.datetime object
:return: ISO-like string representing the datetime
"""
return datetime_obj.isoformat().replace(":", "_").replace('+', '_plus_')
[docs] def _labels_to_key(self, labels):
try_num = 1
try:
try_num = int(labels.get('try_number', '1'))
except ValueError:
self.log.warning("could not get try_number as an int: %s", labels.get('try_number', '1'))
try:
dag_id = labels['dag_id']
task_id = labels['task_id']
ex_time = self._label_safe_datestring_to_datetime(labels['execution_date'])
except Exception as e:
self.log.warning(
'Error while retrieving labels; labels: %s; exception: %s',
labels, e
)
return None
with create_session() as session:
tasks = (
session
.query(TaskInstance)
.filter_by(execution_date=ex_time).all()
)
self.log.info(
'Checking %s task instances.',
len(tasks)
)
for task in tasks:
if (
self._make_safe_label_value(task.dag_id) == dag_id and
self._make_safe_label_value(task.task_id) == task_id and
task.execution_date == ex_time
):
self.log.info(
'Found matching task %s-%s (%s) with current state of %s',
task.dag_id, task.task_id, task.execution_date, task.state
)
dag_id = task.dag_id
task_id = task.task_id
return (dag_id, task_id, ex_time, try_num)
self.log.warning(
'Failed to find and match task details to a pod; labels: %s',
labels
)
return None
[docs] def _flush_watcher_queue(self):
self.log.debug('Executor shutting down, watcher_queue approx. size=%d', self.watcher_queue.qsize())
while True:
try:
task = self.watcher_queue.get_nowait()
# Ignoring it since it can only have either FAILED or SUCCEEDED pods
self.log.warning('Executor shutting down, IGNORING watcher task=%s', task)
self.watcher_queue.task_done()
except Empty:
break
[docs] def terminate(self):
"""Termninates the watcher."""
self.log.debug("Terminating kube_watcher...")
self.kube_watcher.terminate()
self.kube_watcher.join()
self.log.debug("kube_watcher=%s", self.kube_watcher)
self.log.debug("Flushing watcher_queue...")
self._flush_watcher_queue()
# Queue should be empty...
self.watcher_queue.join()
self.log.debug("Shutting down manager...")
self._manager.shutdown()
[docs]class KubernetesExecutor(BaseExecutor, LoggingMixin):
"""Executor for Kubernetes"""
def __init__(self):
self.kube_config = KubeConfig()
self.task_queue = None
self.result_queue = None
self.kube_scheduler = None
self.kube_client = None
self.worker_uuid = None
self._manager = multiprocessing.Manager()
super(KubernetesExecutor, self).__init__(parallelism=self.kube_config.parallelism)
@provide_session
[docs] def clear_not_launched_queued_tasks(self, session=None):
"""
If the airflow scheduler restarts with pending "Queued" tasks, the tasks may or
may not
have been launched Thus, on starting up the scheduler let's check every
"Queued" task to
see if it has been launched (ie: if there is a corresponding pod on kubernetes)
If it has been launched then do nothing, otherwise reset the state to "None" so
the task
will be rescheduled
This will not be necessary in a future version of airflow in which there is
proper support
for State.LAUNCHED
"""
queued_tasks = session\
.query(TaskInstance)\
.filter(TaskInstance.state == State.QUEUED).all()
self.log.info(
'When executor started up, found %s queued task instances',
len(queued_tasks)
)
for task in queued_tasks:
# noinspection PyProtectedMember
# pylint: disable=protected-access
dict_string = (
"dag_id={},task_id={},execution_date={},airflow-worker={}".format(
AirflowKubernetesScheduler._make_safe_label_value(task.dag_id),
AirflowKubernetesScheduler._make_safe_label_value(task.task_id),
AirflowKubernetesScheduler._datetime_to_label_safe_datestring(
task.execution_date
),
self.worker_uuid
)
)
# pylint: enable=protected-access
kwargs = dict(label_selector=dict_string)
if self.kube_config.kube_client_request_args:
for key, value in self.kube_config.kube_client_request_args.items():
kwargs[key] = value
pod_list = self.kube_client.list_namespaced_pod(
self.kube_config.kube_namespace, **kwargs)
if not pod_list.items:
self.log.info(
'TaskInstance: %s found in queued state but was not launched, '
'rescheduling', task
)
session.query(TaskInstance).filter(
TaskInstance.dag_id == task.dag_id,
TaskInstance.task_id == task.task_id,
TaskInstance.execution_date == task.execution_date
).update({TaskInstance.state: State.NONE})
[docs] def _inject_secrets(self):
def _create_or_update_secret(secret_name, secret_path):
try:
return self.kube_client.create_namespaced_secret(
self.kube_config.executor_namespace, kubernetes.client.V1Secret(
data={
'key.json': base64.b64encode(open(secret_path, 'r').read())},
metadata=kubernetes.client.V1ObjectMeta(name=secret_name)),
**self.kube_config.kube_client_request_args)
except ApiException as e:
if e.status == 409:
return self.kube_client.replace_namespaced_secret(
secret_name, self.kube_config.executor_namespace,
kubernetes.client.V1Secret(
data={'key.json': base64.b64encode(
open(secret_path, 'r').read())},
metadata=kubernetes.client.V1ObjectMeta(name=secret_name)),
**self.kube_config.kube_client_request_args)
self.log.exception(
'Exception while trying to inject secret. '
'Secret name: %s, error details: %s',
secret_name, e
)
raise
# For each GCP service account key, inject it as a secret in executor
# namespace with the specific secret name configured in the airflow.cfg.
# We let exceptions to pass through to users.
if self.kube_config.gcp_service_account_keys:
name_path_pair_list = [
{'name': account_spec.strip().split('=')[0],
'path': account_spec.strip().split('=')[1]}
for account_spec in self.kube_config.gcp_service_account_keys.split(',')]
for service_account in name_path_pair_list:
_create_or_update_secret(service_account['name'], service_account['path'])
[docs] def start(self):
"""Starts the executor"""
self.log.info('Start Kubernetes executor')
self.worker_uuid = KubeWorkerIdentifier.get_or_create_current_kube_worker_uuid()
self.log.debug('Start with worker_uuid: %s', self.worker_uuid)
# always need to reset resource version since we don't know
# when we last started, note for behavior below
# https://github.com/kubernetes-client/python/blob/master/kubernetes/docs
# /CoreV1Api.md#list_namespaced_pod
KubeResourceVersion.reset_resource_version()
self.task_queue = self._manager.Queue()
self.result_queue = self._manager.Queue()
self.kube_client = get_kube_client()
self.kube_scheduler = AirflowKubernetesScheduler(
self.kube_config, self.task_queue, self.result_queue,
self.kube_client, self.worker_uuid
)
self._inject_secrets()
self.clear_not_launched_queued_tasks()
[docs] def execute_async(self, key, command, queue=None, executor_config=None):
"""Executes task asynchronously"""
self.log.info(
'Add task %s with command %s with executor_config %s',
key, command, executor_config
)
kube_executor_config = KubernetesExecutorConfig.from_dict(executor_config)
self.task_queue.put((key, command, kube_executor_config))
[docs] def sync(self):
"""Synchronize task state."""
if self.running:
self.log.debug('self.running: %s', self.running)
if self.queued_tasks:
self.log.debug('self.queued: %s', self.queued_tasks)
self.kube_scheduler.sync()
last_resource_version = None
while True:
try:
results = self.result_queue.get_nowait()
try:
key, state, pod_id, resource_version = results
last_resource_version = resource_version
self.log.info('Changing state of %s to %s', results, state)
try:
self._change_state(key, state, pod_id)
except Exception as e:
self.log.exception('Exception: %s when attempting ' +
'to change state of %s to %s, re-queueing.', e, results, state)
self.result_queue.put(results)
finally:
self.result_queue.task_done()
except Empty:
break
KubeResourceVersion.checkpoint_resource_version(last_resource_version)
for _ in range(self.kube_config.worker_pods_creation_batch_size):
try:
task = self.task_queue.get_nowait()
try:
self.kube_scheduler.run_next(task)
except ApiException as e:
self.log.warning('ApiException when attempting to run task, re-queueing. '
'Message: %s' % json.loads(e.body)['message'])
self.task_queue.put(task)
except HTTPError as e:
self.log.warning('HTTPError when attempting to run task, re-queueing. '
'Exception: %s', str(e))
self.task_queue.put(task)
finally:
self.task_queue.task_done()
except Empty:
break
[docs] def _change_state(self, key, state, pod_id):
if state != State.RUNNING:
if self.kube_config.delete_worker_pods:
self.kube_scheduler.delete_pod(pod_id)
self.log.info('Deleted pod: %s', str(key))
try:
self.running.pop(key)
except KeyError:
self.log.debug('Could not find key: %s', str(key))
pass
self.event_buffer[key] = state
[docs] def _flush_task_queue(self):
self.log.debug('Executor shutting down, task_queue approximate size=%d', self.task_queue.qsize())
while True:
try:
task = self.task_queue.get_nowait()
# This is a new task to run thus ok to ignore.
self.log.warning('Executor shutting down, will NOT run task=%s', task)
self.task_queue.task_done()
except Empty:
break
[docs] def _flush_result_queue(self):
self.log.debug('Executor shutting down, result_queue approximate size=%d', self.result_queue.qsize())
while True: # pylint: disable=too-many-nested-blocks
try:
results = self.result_queue.get_nowait()
self.log.warning('Executor shutting down, flushing results=%s', results)
try:
key, state, pod_id, resource_version = results
self.log.info('Changing state of %s to %s : resource_version=%d', results, state,
resource_version)
try:
self._change_state(key, state, pod_id)
except Exception as e: # pylint: disable=broad-except
self.log.exception('Ignoring exception: %s when attempting to change state of %s '
'to %s.', e, results, state)
finally:
self.result_queue.task_done()
except Empty:
break
[docs] def end(self):
"""Called when the executor shuts down"""
self.log.info('Shutting down Kubernetes executor')
self.log.debug('Flushing task_queue...')
self._flush_task_queue()
self.log.debug('Flushing result_queue...')
self._flush_result_queue()
# Both queues should be empty...
self.task_queue.join()
self.result_queue.join()
if self.kube_scheduler:
self.kube_scheduler.terminate()
self._manager.shutdown()