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import time
import warnings
from enum import Enum
from typing import Any, Optional, Union
from tableauserverclient import Pager, PersonalAccessTokenAuth, Server, TableauAuth
from tableauserverclient.server import Auth
from airflow.exceptions import AirflowException
from airflow.hooks.base import BaseHook
[docs]def parse_boolean(val: str) -> Union[str, bool]:
"""Try to parse a string into boolean.
The string is returned as-is if it does not look like a boolean value.
"""
val = val.lower()
if val in ('y', 'yes', 't', 'true', 'on', '1'):
return True
if val in ('n', 'no', 'f', 'false', 'off', '0'):
return False
return val
[docs]class TableauJobFailedException(AirflowException):
"""An exception that indicates that a Job failed to complete."""
[docs]class TableauJobFinishCode(Enum):
"""
The finish code indicates the status of the job.
.. seealso:: https://help.tableau.com/current/api/rest_api/en-us/REST/rest_api_ref.htm#query_job
"""
[docs]class TableauHook(BaseHook):
"""
Connects to the Tableau Server Instance and allows to communicate with it.
Can be used as a context manager: automatically authenticates the connection
when opened and signs out when closed.
.. seealso:: https://tableau.github.io/server-client-python/docs/
:param site_id: The id of the site where the workbook belongs to.
It will connect to the default site if you don't provide an id.
:param tableau_conn_id: The :ref:`Tableau Connection id <howto/connection:tableau>`
containing the credentials to authenticate to the Tableau Server.
"""
[docs] conn_name_attr = 'tableau_conn_id'
[docs] default_conn_name = 'tableau_default'
def __init__(self, site_id: Optional[str] = None, tableau_conn_id: str = default_conn_name) -> None:
super().__init__()
self.tableau_conn_id = tableau_conn_id
self.conn = self.get_connection(self.tableau_conn_id)
self.site_id = site_id or self.conn.extra_dejson.get('site_id', '')
self.server = Server(self.conn.host)
verify: Any = self.conn.extra_dejson.get('verify', True)
if isinstance(verify, str):
verify = parse_boolean(verify)
self.server.add_http_options(
options_dict={'verify': verify, 'cert': self.conn.extra_dejson.get('cert', None)}
)
self.server.use_server_version()
self.tableau_conn = None
[docs] def __enter__(self):
if not self.tableau_conn:
self.tableau_conn = self.get_conn()
return self
[docs] def __exit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
self.server.auth.sign_out()
[docs] def get_conn(self) -> Auth.contextmgr:
"""
Sign in to the Tableau Server.
:return: an authorized Tableau Server Context Manager object.
:rtype: tableauserverclient.server.Auth.contextmgr
"""
if self.conn.login and self.conn.password:
return self._auth_via_password()
if 'token_name' in self.conn.extra_dejson and 'personal_access_token' in self.conn.extra_dejson:
return self._auth_via_token()
raise NotImplementedError('No Authentication method found for given Credentials!')
def _auth_via_password(self) -> Auth.contextmgr:
tableau_auth = TableauAuth(
username=self.conn.login, password=self.conn.password, site_id=self.site_id
)
return self.server.auth.sign_in(tableau_auth)
def _auth_via_token(self) -> Auth.contextmgr:
"""The method is deprecated. Please, use the authentication via password instead."""
warnings.warn(
"Authentication via personal access token is deprecated. "
"Please, use the password authentication to avoid inconsistencies.",
DeprecationWarning,
)
tableau_auth = PersonalAccessTokenAuth(
token_name=self.conn.extra_dejson['token_name'],
personal_access_token=self.conn.extra_dejson['personal_access_token'],
site_id=self.site_id,
)
return self.server.auth.sign_in_with_personal_access_token(tableau_auth)
[docs] def get_all(self, resource_name: str) -> Pager:
"""
Get all items of the given resource.
.. see also:: https://tableau.github.io/server-client-python/docs/page-through-results
:param resource_name: The name of the resource to paginate.
For example: jobs or workbooks.
:return: all items by returning a Pager.
:rtype: tableauserverclient.Pager
"""
try:
resource = getattr(self.server, resource_name)
except AttributeError:
raise ValueError(f"Resource name {resource_name} is not found.")
return Pager(resource.get)
[docs] def get_job_status(self, job_id: str) -> TableauJobFinishCode:
"""
Get the current state of a defined Tableau Job.
.. see also:: https://tableau.github.io/server-client-python/docs/api-ref#jobs
:param job_id: The id of the job to check.
:return: An Enum that describe the Tableau job’s return code
:rtype: TableauJobFinishCode
"""
return TableauJobFinishCode(int(self.server.jobs.get_by_id(job_id).finish_code))
[docs] def wait_for_state(self, job_id: str, target_state: TableauJobFinishCode, check_interval: float) -> bool:
"""
Wait until the current state of a defined Tableau Job is equal
to target_state or different from PENDING.
:param job_id: The id of the job to check.
:param target_state: Enum that describe the Tableau job’s target state
:param check_interval: time in seconds that the job should wait in
between each instance state checks until operation is completed
:return: return True if the job is equal to the target_status, False otherwise.
:rtype: bool
"""
finish_code = self.get_job_status(job_id=job_id)
while finish_code == TableauJobFinishCode.PENDING and finish_code != target_state:
self.log.info("job state: %s", finish_code)
time.sleep(check_interval)
finish_code = self.get_job_status(job_id=job_id)
return finish_code == target_state