Introduction

As cloud applications grow in complexity, secure and efficient networking becomes essential. Google Cloud VPC Connectors allow serverless services like Cloud Run, App Engine, and Cloud Functions to connect to resources inside your Virtual Private Cloud (VPC), enabling private communication with databases, internal APIs, and other services.

What is a VPC Connector?

A VPC Connector is a managed network bridge that lets your serverless workloads access resources in your VPC network. By default, serverless services in GCP have public internet access, but with a VPC Connector, you can route traffic to private IPs, internal services, and restrict outbound traffic for security and compliance.

Benefits

Private Networking: Access internal resources (e.g., Cloud SQL, Redis, private APIs) securely.
Security: Prevent exposure of sensitive services to the public internet.
Compliance: Meet regulatory requirements for data residency and network isolation.
Flexibility: Control egress traffic and apply firewall rules.

Example: Connecting Cloud Run to a Private Cloud SQL Instance

Suppose you have a Cloud Run service that needs to connect to a Cloud SQL database with a private IP. Here’s how you can set up a VPC Connector:

Create a VPC Connector:

gcloud compute networks vpc-access connectors create my-connector \
  --network default \
  --region us-central1 \
  --range 10.8.0.0/28

Deploy Cloud Run with the Connector:

gcloud run deploy my-service \
  --image gcr.io/[PROJECT-ID]/my-service \
  --vpc-connector my-connector \
  --region us-central1

Configure Cloud SQL to use private IP and ensure firewall rules allow traffic from the connector’s subnet.

Best Practices

Choose a subnet range that does not overlap with existing ranges.
Monitor connector usage and health in the GCP Console.
Apply IAM roles to restrict who can create or modify connectors.
Use firewall rules to control access between serverless services and VPC resources.

Conclusion