ephraimbuddy commented on code in PR #42913: URL: https://github.com/apache/airflow/pull/42913#discussion_r1799089176
########## airflow/models/dag_version.py: ########## @@ -0,0 +1,142 @@ +# 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. + +from __future__ import annotations + +import logging +import random +import string +from typing import TYPE_CHECKING + +from sqlalchemy import Column, ForeignKey, Integer, select +from sqlalchemy.orm import relationship + +from airflow.models.base import Base, StringID +from airflow.utils.session import NEW_SESSION, provide_session + +if TYPE_CHECKING: + from sqlalchemy.orm import Session + + from airflow.models.dagcode import DagCode + from airflow.models.serialized_dag import SerializedDagModel + +log = logging.getLogger(__name__) + + +class DagVersion(Base): + """Model to track the versions of DAGs in the database.""" + + __tablename__ = "dag_version" + id = Column(Integer, primary_key=True) + version_number = Column(Integer) + version_name = Column(StringID()) + dag_id = Column(StringID(), ForeignKey("dag.dag_id", ondelete="CASCADE")) + dag_model = relationship("DagModel", back_populates="dag_versions") + dag_code = relationship("DagCode", back_populates="dag_version", uselist=False) + serialized_dag = relationship("SerializedDagModel", back_populates="dag_version", uselist=False) + dag_runs = relationship("DagRun", back_populates="dag_version") + task_instances = relationship("TaskInstance", back_populates="dag_version") + + def __init__( + self, + *, + dag_id: str, + version_number: int, + dag_code: DagCode, + serialized_dag: SerializedDagModel, + version_name: str | None = None, + ): + self.dag_id = dag_id + self.version_number = version_number + self.dag_code = dag_code + self.serialized_dag = serialized_dag + self.version_name = version_name + + def __repr__(self): + return f"<DagVersion {self.dag_id} - {self.version_name}>" + + @classmethod + def _generate_random_string(cls): + letters = string.ascii_letters + string.digits + return "dag-" + "".join(random.choice(letters) for i in range(10)) + + @classmethod + @provide_session + def _generate_unique_random_string(cls, session: Session = NEW_SESSION): + while True: + random_str = cls._generate_random_string() + # Check if the generated string exists + if not session.scalar(select(cls).where(cls.version_name == random_str)): + return random_str + + @classmethod + @provide_session + def write_dag_version( + cls, + *, + dag_id: str, + dag_code: DagCode, + serialized_dag: SerializedDagModel, + version_name: str | None = None, + session: Session = NEW_SESSION, + ): + """Write a new DagVersion into database.""" + existing_dag_version = session.scalar( + select(cls).where(cls.dag_id == dag_id).order_by(cls.version_number.desc()).limit(1) + ) + version_number = 1 + + if existing_dag_version: + version_number = existing_dag_version.version_number + 1 + if not version_name and existing_dag_version: + version_name = existing_dag_version.version_name + + dag_version = DagVersion( + dag_id=dag_id, + version_number=version_number, + dag_code=dag_code, + serialized_dag=serialized_dag, + version_name=version_name or cls._generate_unique_random_string(session), Review Comment: > I think we should augment the version_name we store when a DAG author provides is to us. Otherwise, we'd have the same version_name for all versions until they change it, which isn't great. >e.g. if I have version_name=foo in my DAG, and I add a new task but don't update the version. So maybe something like foo-{version_number} or something? Or maybe we toss on an int to signify when it hasn't changed, but the DAG has, like foo-2. That's my plan, but I want to have it in a method. The `version_number` increments, while the version_name remains the same until changed. However, a method named `version` would return `version_name-version_number` (`foo-2`), which would be used on the UI. I think having them separate is much better than using Python logic, which might go wrong. >We also only stamp a new version when the serdag actually changes. I wonder if we'd be better off combing the user provided version and the serdag hash to determine when to create a new version? The serdag is 1:1 to dag_version. When it changes, the version also changes and there's a link between the two tables which allows us to access the hash e.g : ```python version = session.query(DagVersion).get(1) print(version.serialized_dag.dag_hash) ``` I feel we shouldn't combine the hash and version since a change in the user-provided version name would trigger a new serialized dag version, which also means a new dagversion. The dag_hash can remain an internal property that we use to know that the version has changed -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
