Repository: apache/airflow

Issue:
Migrate MySQL example DAGs to new design
There is a new design of system tests that was introduced by the [AIP-47](https://cwiki.apache.org/confluence/display/AIRFLOW/AIP-47+New+design+of+Airflow+System+Tests).

All current example dags need to be migrated and converted into system tests, so they can be run in the CI process automatically before releases.

This is an aggregated issue for all example DAGs related to `MySQL` provider. It is created to track progress of their migration.

List of paths to example DAGs:
- [x] airflow/providers/mysql/example_dags/example_mysql.py


Discussion:

Resolving patch:
diff --git a/airflow/providers/mysql/example_dags/__init__.py b/airflow/providers/mysql/example_dags/__init__.py
deleted file mode 100644
--- a/airflow/providers/mysql/example_dags/__init__.py
+++ /dev/null
@@ -1,17 +0,0 @@
-#
-# 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.


Test patch:
diff --git a/airflow/providers/mysql/example_dags/example_mysql.py b/tests/system/providers/mysql/example_mysql.py
similarity index 58%
rename from airflow/providers/mysql/example_dags/example_mysql.py
rename to tests/system/providers/mysql/example_mysql.py
--- a/airflow/providers/mysql/example_dags/example_mysql.py
+++ b/tests/system/providers/mysql/example_mysql.py
@@ -18,34 +18,45 @@
 """
 Example use of MySql related operators.
 """
-
+import os
 from datetime import datetime
 
 from airflow import DAG
 from airflow.providers.mysql.operators.mysql import MySqlOperator
 
-dag = DAG(
-    'example_mysql',
+ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID")
+DAG_ID = "example_mysql"
+
+with DAG(
+    DAG_ID,
     start_date=datetime(2021, 1, 1),
     default_args={'mysql_conn_id': 'mysql_conn_id'},
     tags=['example'],
     catchup=False,
-)
+) as dag:
+
+    # [START howto_operator_mysql]
+
+    drop_table_mysql_task = MySqlOperator(
+        task_id='drop_table_mysql', sql=r"""DROP TABLE table_name;""", dag=dag
+    )
+
+    # [END howto_operator_mysql]
 
-# [START howto_operator_mysql]
+    # [START howto_operator_mysql_external_file]
 
-drop_table_mysql_task = MySqlOperator(task_id='drop_table_mysql', sql=r"""DROP TABLE table_name;""", dag=dag)
+    mysql_task = MySqlOperator(
+        task_id='drop_table_mysql_external_file',
+        sql='/scripts/drop_table.sql',
+        dag=dag,
+    )
 
-# [END howto_operator_mysql]
+    # [END howto_operator_mysql_external_file]
 
-# [START howto_operator_mysql_external_file]
+    drop_table_mysql_task >> mysql_task
 
-mysql_task = MySqlOperator(
-    task_id='drop_table_mysql_external_file',
-    sql='/scripts/drop_table.sql',
-    dag=dag,
-)
 
-# [END howto_operator_mysql_external_file]
+from tests.system.utils import get_test_run  # noqa: E402
 
-drop_table_mysql_task >> mysql_task
+# Needed to run the example DAG with pytest (see: tests/system/README.md#run_via_pytest)
+test_run = get_test_run(dag)