# -*- coding: utf-8 -*-
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import requests
from airflow import __version__
from airflow.exceptions import AirflowException
from airflow.hooks.base_hook import BaseHook
from requests import exceptions as requests_exceptions
from requests.auth import AuthBase
from time import sleep
from six.moves.urllib import parse as urlparse
[docs]RESTART_CLUSTER_ENDPOINT = ("POST", "api/2.0/clusters/restart")
[docs]START_CLUSTER_ENDPOINT = ("POST", "api/2.0/clusters/start")
[docs]TERMINATE_CLUSTER_ENDPOINT = ("POST", "api/2.0/clusters/delete")
[docs]RUN_NOW_ENDPOINT = ('POST', 'api/2.0/jobs/run-now')
[docs]SUBMIT_RUN_ENDPOINT = ('POST', 'api/2.0/jobs/runs/submit')
[docs]GET_RUN_ENDPOINT = ('GET', 'api/2.0/jobs/runs/get')
[docs]CANCEL_RUN_ENDPOINT = ('POST', 'api/2.0/jobs/runs/cancel')
[docs]class DatabricksHook(BaseHook):
"""
Interact with Databricks.
"""
def __init__(
self,
databricks_conn_id='databricks_default',
timeout_seconds=180,
retry_limit=3,
retry_delay=1.0):
"""
:param databricks_conn_id: The name of the databricks connection to use.
:type databricks_conn_id: str
:param timeout_seconds: The amount of time in seconds the requests library
will wait before timing-out.
:type timeout_seconds: int
:param retry_limit: The number of times to retry the connection in case of
service outages.
:type retry_limit: int
:param retry_delay: The number of seconds to wait between retries (it
might be a floating point number).
:type retry_delay: float
"""
self.databricks_conn_id = databricks_conn_id
self.databricks_conn = self.get_connection(databricks_conn_id)
self.timeout_seconds = timeout_seconds
if retry_limit < 1:
raise ValueError('Retry limit must be greater than equal to 1')
self.retry_limit = retry_limit
self.retry_delay = retry_delay
@staticmethod
[docs] def _parse_host(host):
"""
The purpose of this function is to be robust to improper connections
settings provided by users, specifically in the host field.
For example -- when users supply ``https://xx.cloud.databricks.com`` as the
host, we must strip out the protocol to get the host.::
h = DatabricksHook()
assert h._parse_host('https://xx.cloud.databricks.com') == \
'xx.cloud.databricks.com'
In the case where users supply the correct ``xx.cloud.databricks.com`` as the
host, this function is a no-op.::
assert h._parse_host('xx.cloud.databricks.com') == 'xx.cloud.databricks.com'
"""
urlparse_host = urlparse.urlparse(host).hostname
if urlparse_host:
# In this case, host = https://xx.cloud.databricks.com
return urlparse_host
else:
# In this case, host = xx.cloud.databricks.com
return host
[docs] def _do_api_call(self, endpoint_info, json):
"""
Utility function to perform an API call with retries
:param endpoint_info: Tuple of method and endpoint
:type endpoint_info: tuple[string, string]
:param json: Parameters for this API call.
:type json: dict
:return: If the api call returns a OK status code,
this function returns the response in JSON. Otherwise,
we throw an AirflowException.
:rtype: dict
"""
method, endpoint = endpoint_info
url = 'https://{host}/{endpoint}'.format(
host=self._parse_host(self.databricks_conn.host),
endpoint=endpoint)
if 'token' in self.databricks_conn.extra_dejson:
self.log.info('Using token auth.')
auth = _TokenAuth(self.databricks_conn.extra_dejson['token'])
else:
self.log.info('Using basic auth.')
auth = (self.databricks_conn.login, self.databricks_conn.password)
if method == 'GET':
request_func = requests.get
elif method == 'POST':
request_func = requests.post
else:
raise AirflowException('Unexpected HTTP Method: ' + method)
attempt_num = 1
while True:
try:
response = request_func(
url,
json=json,
auth=auth,
headers=USER_AGENT_HEADER,
timeout=self.timeout_seconds)
response.raise_for_status()
return response.json()
except requests_exceptions.RequestException as e:
if not _retryable_error(e):
# In this case, the user probably made a mistake.
# Don't retry.
raise AirflowException('Response: {0}, Status Code: {1}'.format(
e.response.content, e.response.status_code))
self._log_request_error(attempt_num, e)
if attempt_num == self.retry_limit:
raise AirflowException(('API requests to Databricks failed {} times. ' +
'Giving up.').format(self.retry_limit))
attempt_num += 1
sleep(self.retry_delay)
[docs] def _log_request_error(self, attempt_num, error):
self.log.error(
'Attempt %s API Request to Databricks failed with reason: %s',
attempt_num, error
)
[docs] def run_now(self, json):
"""
Utility function to call the ``api/2.0/jobs/run-now`` endpoint.
:param json: The data used in the body of the request to the ``run-now`` endpoint.
:type json: dict
:return: the run_id as a string
:rtype: str
"""
response = self._do_api_call(RUN_NOW_ENDPOINT, json)
return response['run_id']
[docs] def submit_run(self, json):
"""
Utility function to call the ``api/2.0/jobs/runs/submit`` endpoint.
:param json: The data used in the body of the request to the ``submit`` endpoint.
:type json: dict
:return: the run_id as a string
:rtype: str
"""
response = self._do_api_call(SUBMIT_RUN_ENDPOINT, json)
return response['run_id']
[docs] def get_run_page_url(self, run_id):
json = {'run_id': run_id}
response = self._do_api_call(GET_RUN_ENDPOINT, json)
return response['run_page_url']
[docs] def get_run_state(self, run_id):
json = {'run_id': run_id}
response = self._do_api_call(GET_RUN_ENDPOINT, json)
state = response['state']
life_cycle_state = state['life_cycle_state']
# result_state may not be in the state if not terminal
result_state = state.get('result_state', None)
state_message = state['state_message']
return RunState(life_cycle_state, result_state, state_message)
[docs] def cancel_run(self, run_id):
json = {'run_id': run_id}
self._do_api_call(CANCEL_RUN_ENDPOINT, json)
[docs] def restart_cluster(self, json):
self._do_api_call(RESTART_CLUSTER_ENDPOINT, json)
[docs] def start_cluster(self, json):
self._do_api_call(START_CLUSTER_ENDPOINT, json)
[docs] def terminate_cluster(self, json):
self._do_api_call(TERMINATE_CLUSTER_ENDPOINT, json)
[docs]def _retryable_error(exception):
return isinstance(exception, requests_exceptions.ConnectionError) \
or isinstance(exception, requests_exceptions.Timeout) \
or exception.response is not None and exception.response.status_code >= 500
[docs]RUN_LIFE_CYCLE_STATES = [
'PENDING',
'RUNNING',
'TERMINATING',
'TERMINATED',
'SKIPPED',
'INTERNAL_ERROR'
]
[docs]class RunState:
"""
Utility class for the run state concept of Databricks runs.
"""
def __init__(self, life_cycle_state, result_state, state_message):
self.life_cycle_state = life_cycle_state
self.result_state = result_state
self.state_message = state_message
@property
[docs] def is_terminal(self):
if self.life_cycle_state not in RUN_LIFE_CYCLE_STATES:
raise AirflowException(
('Unexpected life cycle state: {}: If the state has '
'been introduced recently, please check the Databricks user '
'guide for troubleshooting information').format(
self.life_cycle_state))
return self.life_cycle_state in ('TERMINATED', 'SKIPPED', 'INTERNAL_ERROR')
@property
[docs] def is_successful(self):
return self.result_state == 'SUCCESS'
[docs] def __eq__(self, other):
return self.life_cycle_state == other.life_cycle_state and \
self.result_state == other.result_state and \
self.state_message == other.state_message
[docs] def __repr__(self):
return str(self.__dict__)
[docs]class _TokenAuth(AuthBase):
"""
Helper class for requests Auth field. AuthBase requires you to implement the __call__
magic function.
"""
def __init__(self, token):
self.token = token
[docs] def __call__(self, r):
r.headers['Authorization'] = 'Bearer ' + self.token
return r