Inter project private connectivity

[nikhildobriyal]

I have a CLOUD SQL instance for MySQL in project A and I execute some select queries on DB from a compute engine in project B using public IP of SQL instance, is there any way to connect to my SQL using private IP from a different project.

[ms4446]

Yes, you can connect to your Cloud SQL instance using a private IP address from a different project in Google Cloud. There are three primary solutions for this:

1. Private Service Connect (PSC):

   • PSC is a recommended and secure method for connecting services across projects using private IPs, without exposing them to the public internet.
   • To use PSC, create a service attachment in Project A (where your Cloud SQL instance resides) and a corresponding service endpoint in Project B (where your Compute Engine instance is located).
   • This method is straightforward and enhances security by keeping traffic within Google's network.
   • For detailed instructions, refer to the Private Service Connect documentation.

2. VPC Peering:

   • VPC Peering involves connecting the VPC networks of Project A and Project B, allowing the Compute Engine in Project B to access the Cloud SQL instance in Project A using its private IP.
   • It requires careful planning, especially regarding IP address range conflicts and firewall configurations, to ensure seamless connectivity.
   • While effective, this solution might be complex for intricate network setups.
   • Detailed setup information can be found in the VPC Peering documentation.

3. Cloud SQL Auth Proxy:

   • The Cloud SQL Auth Proxy provides a secure tunnel for connecting to your Cloud SQL instance.
   • Install the Auth Proxy on your Compute Engine instance in Project B and configure it to connect to the Cloud SQL instance in Project A.
   • This method adds an extra layer of security and is useful when direct connectivity via private IPs is not feasible.
   • It does require ongoing management and maintenance.
   • For more information on installation and configuration, consult the Cloud SQL Auth Proxy documentation.

Choosing the Best Solution:

• The optimal solution depends on your specific requirements and network setup.
• Private Service Connect is ideal for a secure, straightforward solution.
• VPC Peering is suitable if you are comfortable with network configurations and have a relatively simple network setup.
• The Cloud SQL Auth Proxy offers flexibility and enhanced security, especially in complex network scenarios.

Additional Considerations:

• Ensure the Compute Engine instance in Project B has the necessary permissions to access the Cloud SQL instance in Project A.
• Prioritize security in your setup, including SSL/TLS configurations and firewall rules.
• Be aware of potential network costs and the complexity associated with each method.
• Consider the maintenance and management requirements, especially for the Cloud SQL Auth Proxy.

[nikhildobriyal]

Peering Connection: I am using auto mode VPC in both projects and the resources are deployed in same region, therefore the Subnet CIDR is overlapping and we cannot setup peering connection, so this method removed in this scenario.

Private Service Connect: This connectivity type cannot be enable on an existing SQL instance, which I have, so this is also removed in this scenario.

For Cloud SQL auth proxy: can I setup it from a compute engine?

[ms4446]

Given the constraints you've outlined, it seems that both VPC Peering and Private Service Connect are not viable options in your scenario due to overlapping subnet CIDRs in auto mode VPCs and the inability to enable Private Service Connect on an existing SQL instance.

However, the Cloud SQL Auth Proxy remains a feasible solution. Yes, you can set up the Cloud SQL Auth Proxy on a Compute Engine instance. Here's how you can do it:

1. Install the Cloud SQL Auth Proxy on Compute Engine:

   • First, you need to install the Cloud SQL Auth Proxy on your Compute Engine instance in Project B. The Cloud SQL Auth Proxy is available for download and can be installed on Linux, Windows, and macOS systems.

2. Authentication:

   • The Cloud SQL Auth Proxy uses Google Cloud IAM for authentication. Ensure that the Compute Engine instance has the necessary IAM roles and permissions to access the Cloud SQL instance in Project A.
   • Typically, you would use a service account with the appropriate roles for this purpose.

3. Configuration:

   • Once installed, you need to configure the Cloud SQL Auth Proxy with the details of your Cloud SQL instance. This includes the instance connection name, which is in the format project-id:region:instance-name.
   • You can start the proxy with a command like ./cloud_sql_proxy -instances=myProject:us-central1:myInstance=tcp:3306, which will listen on port 3306 on your Compute Engine instance.

4. Connecting to Cloud SQL:

   • With the Cloud SQL Auth Proxy running, you can connect to your Cloud SQL instance using standard MySQL client software on the Compute Engine instance. The connection is made to localhost on the port you configured the proxy to listen to (e.g., 3306).

5. Security Considerations:

   • The Cloud SQL Auth Proxy provides a secure connection to your Cloud SQL instance. It's important to ensure that only authorized users and applications on the Compute Engine instance can access the port the proxy is listening on.
   • You might also want to configure the Compute Engine's firewall rules to restrict access to the port used by the Cloud SQL Auth Proxy.

6. Running the Proxy as a Service:

   • For production environments, it's recommended to run the Cloud SQL Auth Proxy as a service so that it starts automatically when the Compute Engine instance boots up. This can be achieved using systemd or similar service management tools on Linux.