Parse JSON template parameters field for MySQL operator

airflow/providers/mysql/operators/mysql.py

@@ -15,6 +15,7 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
+import ast
 from typing import Dict, Iterable, Mapping, Optional, Union
 
 from airflow.models import BaseOperator
@@ -37,6 +38,8 @@ class MySqlOperator(BaseOperator):
     :param mysql_conn_id: Reference to :ref:`mysql connection id <howto/connection:mysql>`.
     :type mysql_conn_id: str
     :param parameters: (optional) the parameters to render the SQL query with.
+        Template reference are recognized by str ending in '.json'
+        (templated)
     :type parameters: dict or iterable
     :param autocommit: if True, each command is automatically committed.
         (default value: False)
@@ -67,6 +70,11 @@ def __init__(
         self.parameters = parameters
         self.database = database
 
+    def prepare_template(self) -> None:
+        """Parse template file for attribute parameters."""
+        if isinstance(self.parameters, str):
+            self.parameters = ast.literal_eval(self.parameters)
+
     def execute(self, context: Dict) -> None:
         self.log.info('Executing: %s', self.sql)
         hook = MySqlHook(mysql_conn_id=self.mysql_conn_id, schema=self.database)

tests/providers/mysql/operators/test_mysql.py

@@ -15,8 +15,10 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
+import os
 import unittest
 from contextlib import closing
+from tempfile import NamedTemporaryFile
 
 import pytest
 from parameterized import parameterized
@@ -108,3 +110,19 @@ def test_overwrite_schema(self, client):
                 op.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE, ignore_ti_state=True)
             except OperationalError as e:
                 assert "Unknown database 'foobar'" in str(e)
+
+    def test_mysql_operator_resolve_parameters_template_json_file(self):
+
+        with NamedTemporaryFile(suffix='.json') as f:
+            f.write(b"{\n \"foo\": \"{{ ds }}\"}")
+            f.flush()
+            template_dir = os.path.dirname(f.name)
+            template_file = os.path.basename(f.name)
+
+            with DAG("test-dag", start_date=DEFAULT_DATE, template_searchpath=template_dir):
+                task = MySqlOperator(task_id="op1", parameters=template_file, sql="SELECT 1")
+
+            task.resolve_template_files()
+
+        assert isinstance(task.parameters, dict)
+        assert task.parameters["foo"] == "{{ ds }}"