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Access Aiven services from Google Cloud Functions via VPC peering

You can access Aiven service by creating a Serverless VPC access connector and Google Cloud Function.

By default, Google Cloud Functions can only access the Internet and is not able to access your GCP VPC or Aiven VPC.

For Google Cloud Functions to access VPC, Serverless VPC access connector is required. Serverless VPC access connector consists of two or more Google-managed VM that forward requests (and perform NAT) from Cloud Functions to your GCP VPC and Aiven VPC.


You have:

Create a Serverless VPC access connector

  1. Open GCP console and go to Navigation menu > Networking > VPC network and select Serverless VPC access.

  2. Click Create connector:

    • Name: The connector name of your choice.
    • Region: The region where to create the Cloud Function.
    • Network: Your GCP VPC, which is already peered to Aiven VPC already.
    • Subnet: Select custom IP range and enter a /28 private subnet that is not in use.
  3. If you have allowed IP addresses configured on your Aiven service, ensure the subnet of serverless VPC access connector is listed there

Create a Cloud Function

  1. Open GCP console and under Navigation menu, Serverless section, select Cloud Functions.

  2. Click create function

    • Environment: Your choice of environment. You can use the the default value (2nd gen).
    • Function name: the name of your choice.
    • Region: The region of the serverless VPC access connector.
    • Click and expand the runtime, build connections and security settings section, select Connections tab, and select the serverless VPC access connector you have created.
    • Click Next
  3. Select the runtime of your choice.


    Do not click Test function.

  4. Click Deploy

  5. Wait for GCP to deploy the cloud function. Once deployed, use the Source tab to edit the function if needed.


    Do not click Test function.

  6. Click the Testing tab and test the command in Cloud Shell to ensure it can access VPC.


If you cannot access your VPC or Aiven VPC from the Cloud Function, consider using the following example for troubleshooting purposes.

# Cound Function 2nd gen, Python 3.11
import functions_framework
import socket


def hello_http(request):
request_json = request.get_json(silent=True)

if request_json and "cloud_function_key" in request_json and request_json["cloud_function_key"] == CLOUD_FUNCTION_KEY:
result = ""
host = request_json['host']
port = request_json['port']
timeout = request_json.get('timeout', 10)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
result = "OK"
except Exception as e:
result = repr(e)
return 'Result: {}\n'.format(result)
return "HTTP 401\n", 401

The request body contains:

  • CLOUD_FUNCTION_KEY Change this to protect your Cloud Function endpoint, especially if it does not require authentication.
  • host: FQDN or IP address if your Aiven service or VM in your GCP VPC.
  • port: Destination TCP port number.

Example: In the Testing tab in your Cloud Function:

"cloud_function_key": "gcf-aiven-test-CHANGE_ME_FOR_SECURITY_REASON",
"host": "",
"port": 12345

The request returns:

  • OK if it can establish TCP 3-way handshake.
  • TimeoutError if it cannot reach the specified port.

For assistance, contact Aiven support. When you do, share your your Cloud Function endpoint and CLOUD_FUNCTION_KEY.