Cloud Functions "Connection Refused" when connecting to Cloud SQL

Question

I am trying to follow along with the example provided by Google to connect a Cloud Functions script to Cloud SQL with Python and a MySQL instance.

I have created a Cloud SQL instance in the project and then created a Cloud Function in which I pasted the entire script from the link into the inline editor. I set the environment variables equal to what they need to be in order to connect to Cloud SQL but I am getting an error.

Is there something obvious I am missing in order to make this work?

Error: function crashed. Details: (2003, "Can't connect to MySQL server on 'localhost' ([Errno 111] Connection refused)")

Traceback (most recent call last): File "/env/local/lib/python3.7/site-packages/pymysql/connections.py", line 582, in connect **kwargs) File "/opt/python3.7/lib/python3.7/socket.py", line 727, in create_connection raise err File "/opt/python3.7/lib/python3.7/socket.py", line 716, in create_connection sock.connect(sa) ConnectionRefusedError: [Errno 111] Connection refused During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/user_code/main.py", line 49, in mysql_demo mysql_conn = pymysql.connect(**mysql_config) File "/env/local/lib/python3.7/site-packages/pymysql/init.py", line 94, in Connect return Connection(*args, **kwargs) File "/env/local/lib/python3.7/site-packages/pymysql/connections.py", line 327, in init self.connect() File "/env/local/lib/python3.7/site-packages/pymysql/connections.py", line 629, in connect raise exc pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on 'localhost' ([Errno 111] Connection refused)") During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/env/local/lib/python3.7/site-packages/pymysql/connections.py", line 570, in connect sock.connect(self.unix_socket) ConnectionRefusedError: [Errno 111] Connection refused During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/env/local/lib/python3.7/site-packages/google/cloud/functions_v1beta2/worker.py", line 297, in run_http_function result = _function_handler.invoke_user_function(flask.request) File "/env/local/lib/python3.7/site-packages/google/cloud/functions_v1beta2/worker.py", line 199, in invoke_user_function return call_user_function(request_or_event) File "/env/local/lib/python3.7/site-packages/google/cloud/functions_v1beta2/worker.py", line 192, in call_user_function return self._user_function(request_or_event) File "/user_code/main.py", line 53, in mysql_demo mysql_conn = pymysql.connect(**mysql_config) File "/env/local/lib/python3.7/site-packages/pymysql/init.py", line 94, in Connect return Connection(*args, **kwargs) File "/env/local/lib/python3.7/site-packages/pymysql/connections.py", line 327, in init self.connect() File "/env/local/lib/python3.7/site-packages/pymysql/connections.py", line 629, in connect raise exc pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on 'localhost' ([Errno 111] Connection refused)")

Answer 1

Very important information:

Before you can get started, you need to go the GCP IAM to add the cloud SQL admin role to the cloud function service account. The service account information can be found in the general tab of the cloud function. After you complete this action, you should be good to go. If not, try to add more roles to your cloud function service account like project editor.

For code reference,( only part to change)

# TODO(developer): specify SQL connection details  
CONNECTION_NAME = getenv(
'INSTANCE_CONNECTION_NAME',
'proj-chatbot-og:us-central1:your connection name')
# Please don't change the name on the left like MYSQL_USER
DB_USER = getenv('MYSQL_USER', 'your user name')
DB_PASSWORD = getenv('MYSQL_PASSWORD', 'your password')
DB_NAME = getenv('MYSQL_DATABASE', 'your sql database')


mysql_config = {
'user': DB_USER,
'password': DB_PASSWORD,
'db': DB_NAME,
'charset': 'utf8mb4',
'cursorclass': pymysql.cursors.DictCursor,
'autocommit': True
}

The full documentation can be found in here https://cloud.google.com/functions/docs/sql

Please vote the solution if you found the solution solved your issue.