kaxil commented on a change in pull request #6788: [AIRFLOW-5944] Display rendered template_fields without accessing DAG files URL: https://github.com/apache/airflow/pull/6788#discussion_r391547348
########## File path: airflow/models/renderedtifields.py ########## @@ -0,0 +1,135 @@ +# +# 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. +"""Save Rendered Template Fields """ +from typing import Optional + +import sqlalchemy_jsonfield +from sqlalchemy import Column, String, and_, tuple_ +from sqlalchemy.orm import Session + +from airflow.configuration import conf +from airflow.models.base import ID_LEN, Base +from airflow.models.taskinstance import TaskInstance +from airflow.serialization.helpers import serialize_template_field +from airflow.settings import json +from airflow.utils.session import provide_session +from airflow.utils.sqlalchemy import UtcDateTime + + +class RenderedTaskInstanceFields(Base): + """ + Save Rendered Template Fields + """ + + __tablename__ = "rendered_task_instance_fields" + + dag_id = Column(String(ID_LEN), primary_key=True) + task_id = Column(String(ID_LEN), primary_key=True) + execution_date = Column(UtcDateTime, primary_key=True) + rendered_fields = Column(sqlalchemy_jsonfield.JSONField(json=json), nullable=False) + + def __init__(self, ti: TaskInstance, render_templates=True): + self.dag_id = ti.dag_id + self.task_id = ti.task_id + self.task = ti.task + self.execution_date = ti.execution_date + self.ti = ti + if render_templates: + ti.render_templates() + self.rendered_fields = { + field: serialize_template_field( + getattr(self.task, field) + ) for field in self.task.template_fields + } + + def __repr__(self): + return f"<{self.__class__.__name__}: {self.dag_id}.{self.task_id} {self.execution_date}" + + @classmethod + @provide_session + def get_templated_fields(cls, ti: TaskInstance, session: Session = None) -> Optional[dict]: + """ + Get templated field for a TaskInstance from the RenderedTaskInstanceFields + table. + + :param ti: Task Instance + :param session: SqlAlchemy Session + :return: Rendered Templated TI field + """ + result = session.query(cls.rendered_fields).filter( + cls.dag_id == ti.dag_id, + cls.task_id == ti.task_id, + cls.execution_date == ti.execution_date + ).one_or_none() + + if result: + rendered_fields = result.rendered_fields + return rendered_fields + else: + return None + + @provide_session + def write(self, session: Session = None): + """Write instance to database + + :param session: SqlAlchemy Session + """ + session.merge(self) + + @classmethod + @provide_session + def delete_old_records( + cls, task_id: str, dag_id: str, + num_to_keep=conf.getint("core", "max_num_rendered_ti_fields_per_task", fallback=0), + session: Session = None + ): + """ + Keep only Last X (num_to_keep) number of records for a task by deleting others + + :param task_id: Task ID + :param dag_id: Dag ID + :param num_to_keep: Number of Records to keep + :param session: SqlAlchemy Session + """ + if num_to_keep > 0: + # Fetch Top X records given dag_id & task_id ordered by Execution Date + subq1 = ( + session + .query(cls.dag_id, cls.task_id, cls.execution_date) + .filter(cls.dag_id == dag_id, cls.task_id == task_id) + .order_by(cls.execution_date.desc()) + .limit(num_to_keep) + .subquery('subq1') + ) + + # Second Subquery + # Workaround for MySQL Limitation (https://stackoverflow.com/a/19344141/5691525) + # Limitation: This version of MySQL does not yet support + # LIMIT & IN/ALL/ANY/SOME subquery + subq2 = ( + session + .query(subq1.c.dag_id, subq1.c.task_id, subq1.c.execution_date) + .subquery('subq2') + ) + + session.query(cls) \ + .filter(and_( + cls.dag_id == dag_id, + cls.task_id == task_id, + tuple_(cls.dag_id, cls.task_id, cls.execution_date).notin_(subq2))) \ Review comment: I will create a new issue to sort this out ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
