Coverage for airflow.operators.presto_check_operator : 60%

from airflow.hooks import PrestoHook 

from airflow.operators import CheckOperator, ValueCheckOperator, IntervalCheckOperator 

from airflow.utils import apply_defaults 

class PrestoCheckOperator(CheckOperator): 

    """ 

    Performs checks against Presto. The ``PrestoCheckOperator`` expects 

    a sql query that will return a single row. Each value on that 

    first row is evaluated using python ``bool`` casting. If any of the 

    values return ``False`` the check is failed and errors out. 

    Note that Python bool casting evals the following as ``False``: 

    * False 

    * 0 

    * Empty string (``""``) 

    * Empty list (``[]``) 

    * Empty dictionary or set (``{}``) 

    Given a query like ``SELECT COUNT(*) FROM foo``, it will fail only if 

    the count ``== 0``. You can craft much more complex query that could, 

    for instance, check that the table has the same number of rows as 

    the source table upstream, or that the count of today's partition is 

    greater than yesterday's partition, or that a set of metrics are less 

    than 3 standard deviation for the 7 day average. 

    This operator can be used as a data quality check in your pipeline, and 

    depending on where you put it in your DAG, you have the choice to 

    stop the critical path, preventing from 

    publishing dubious data, or on the side and receive email alterts 

    without stopping the progress of the DAG. 

    :param sql: the sql to be executed 

    :type sql: string 

    :param presto_conn_id: reference to the Presto database 

    :type presto_conn_id: string 

    """ 

    @apply_defaults 

    def __init__( 

            self, sql, 

            presto_conn_id='presto_default', 

            *args, **kwargs): 

        super(PrestoCheckOperator, self).__init__(sql=sql, *args, **kwargs) 

        self.presto_conn_id = presto_conn_id 

        self.sql = sql 

    def get_db_hook(self): 

        return PrestoHook(presto_conn_id=self.presto_conn_id) 

class PrestoValueCheckOperator(ValueCheckOperator): 

    """ 

    Performs a simple value check using sql code. 

    :param sql: the sql to be executed 

    :type sql: string 

    :param presto_conn_id: reference to the Presto database 

    :type presto_conn_id: string 

    """ 

    @apply_defaults 

    def __init__( 

            self, sql, pass_value, tolerance=None, 

            presto_conn_id='presto_default', 

            *args, **kwargs): 

        super(PrestoValueCheckOperator, self).__init__(sql, pass_value, tolerance, *args, **kwargs) 

        self.presto_conn_id = presto_conn_id 

    def get_db_hook(self): 

        return PrestoHook(presto_conn_id=self.presto_conn_id) 

class PrestoIntervalCheckOperator(IntervalCheckOperator): 

    """ 

    Checks that the values of metrics given as SQL expressions are within 

    a certain tolerance of the ones from days_back before. 

    :param table: the table name 

    :type table: str 

    :param days_back: number of days between ds and the ds we want to check 

        against. Defaults to 7 days 

    :type days_back: int 

    :param metrics_threshold: a dictionary of ratios indexed by metrics 

    :type metrics_threshold: dict 

    :param presto_conn_id: reference to the Presto database 

    :type presto_conn_id: string 

    """ 

    @apply_defaults 

    def __init__( 

            self, table, metrics_thresholds, 

            date_filter_column='ds', days_back=-7, 

            presto_conn_id='presto_default', 

            *args, **kwargs): 

        super(PrestoIntervalCheckOperator, self).__init__(table, metrics_thresholds, date_filter_column, days_back, *args, **kwargs) 

        self.presto_conn_id = presto_conn_id 

    def get_db_hook(self): 

        return PrestoHook(presto_conn_id=self.presto_conn_id)