Cloud SQL Private Service Connect

[hugalt01]

I have a private instance of Cloud SQL, need external tableu clients to connect to the private IP of the instance.  Would Private Service Connect be an option here?

[ms4446]

Yes, Private Service Connect (PSC) is an excellent option for enabling external Tableau clients to connect to a Cloud SQL instance using a private IP address. PSC facilitates secure connections across Google Cloud networks or from your on-premises environment to Google Cloud services without the need for public internet exposure. This setup is ideal for maintaining the privacy of your Cloud SQL instance.

Here's how to utilize PSC for this purpose:

1. Create a Private Connection: Establish a PSC endpoint within the same Virtual Private Cloud (VPC) as your Cloud SQL instance. This endpoint creates a private pathway for your Tableau clients to access your database securely. It's important to note that PSC achieves this secure connectivity in conjunction with VPC peering.

2. Configure DNS: Ensure that the DNS name of your Cloud SQL instance (e.g., 'my-database.myproject') resolves to the internal IP address assigned by the PSC endpoint. This configuration allows Tableau to locate and connect to your database using its private address.

3. Set Up Networking: The approach to networking setup will vary based on the location of your Tableau clients:

   • On-premises or in another cloud: Utilize VPNs or Cloud Interconnect to establish a secure connection between your external network and Google Cloud.
   • Within the same GCP project or organization: Simple VPC peering between the relevant VPCs may suffice for connectivity.

4. Configure Cloud SQL and Tableau: Configure your Cloud SQL instance to accept connections from the PSC endpoint. In Tableau, specify your Cloud SQL instance's DNS name (e.g., 'my-database.myproject') for the connection settings.

5. Security and IAM: Implement appropriate IAM roles, such as compute.networkUser, to manage access permissions for Tableau's connection to the database. Additionally, ensure your Cloud SQL instance is configured with the necessary access controls to secure the connection.

Important Considerations:

• Costs: Be mindful of the potential costs associated with using PSC and any additional networking tools (e.g., VPNs, Cloud Interconnect) required for your setup.
• Performance: Consider the potential impact on connection speed, especially if your Tableau clients are geographically distant from the Cloud SQL instance's region. Optimal placement and network configuration can mitigate latency issues.
• Monitoring and Troubleshooting: Implement comprehensive monitoring and logging to keep track of the health of your connections. This will enable you to quickly identify and address any connectivity issues that arise.

By leveraging Private Service Connect, you can ensure that your Cloud SQL instance remains private and secure while still providing external Tableau clients with seamless access as if they were connected within the same network. This approach enhances security without compromising on usability or performance.

[hugalt01 · Accepted solution]

Thanks ms4446 for providing the details.  The use case is for tableau clients deployed in other GCP projects belonging to the same organization.    

I set up a Cloudsql database with PSC enabled by passing the parameter "--enable-private-service-connect", the grabbed the service attachment link off the instance 

(pscServiceAttachmentLink)

Then created the Private Service Connect endpoint and pointed it to the Cloud SQL service attachment.  This worked for clients that were located in subnets within the same region as the PSC endpoint, if the client was located in a subnet of a different region, then it failed to  connect.  Is this a limitation? Please advise.

PS - No VPC peering was necessary when using the PSC endpoint

[ms4446]

Based on your description, it seems you've encountered a regional limitation when using Private Service Connect (PSC) with Cloud SQL across different regions within the same organization.

Private Service Connect allows for the creation of private connections between Google Cloud services (like Cloud SQL) and your VPC networks. When you enable PSC for a Cloud SQL instance and create a PSC endpoint in a VPC, you're essentially creating a private pathway for services in that VPC to access the Cloud SQL instance without traversing the public internet.

PSC endpoints are regional resources, meaning they are designed to facilitate access to services within the same region. This regional design is primarily for performance and security reasons, ensuring that data does not unnecessarily traverse multiple regions, which could introduce latency and potential regulatory concerns.

When clients in a subnet of a different region attempt to connect to a Cloud SQL instance via a PSC endpoint, they may fail to connect because PSC does not automatically route traffic across regions. This behavior is consistent with the regional nature of PSC and is a known limitation.

Solutions and Workarounds

1. Multi-Region Setup: If you have clients in multiple regions that need to access the Cloud SQL instance, consider creating PSC endpoints in each of those regions. Each regional endpoint would need to connect to the Cloud SQL instance. This approach requires careful planning around IP address management and DNS resolution to ensure clients connect to the nearest endpoint.

2. Global Load Balancing: For services that support it, using a global load balancer can help manage cross-regional traffic. However, this is more applicable to compute resources than to Cloud SQL.

3. Cross-Region Networking Solutions: While PSC itself may not support cross-regional connections directly, other networking solutions like Cloud VPN or Cloud Interconnect can facilitate cross-regional connectivity. These solutions can be used in conjunction with PSC to enable secure, cross-regional access to Cloud SQL instances. This would involve setting up secure tunnels between regions and ensuring proper routing is in place.

The issue you're experiencing with cross-regional connectivity to a Cloud SQL instance via PSC is a result of the regional nature of PSC endpoints. To address this, you'll need to implement a solution that accommodates the regional design of PSC, such as deploying regional PSC endpoints or utilizing other Google Cloud networking services for cross-regional connectivity.

It's also worth noting that Google Cloud continuously evolves its services, so it's a good idea to check the latest documentation or reach out to Google Cloud support for any new features or best practices that might help in your scenario.

[hugalt01]

Update:

ms4446 - thanks for providing additional details.

I was able to make the endpoint work in a different region by just enabling "Global Access" on the endpoint created in the consumer VPC. This is working as expected.  

Thanks

[kronus86]

Is it possible to enable PSC on existing Cloudsql database. Till now I have only found a way to enable it at the time of creation.

[ms4446]

Unfortunately, you cannot enable Private Service Connect (PSC) on an existing Cloud SQL instance directly.

• When you enable PSC during Cloud SQL instance creation, it provisions a network interface for the service and assigns a Service Attachment associated with the instance.
• This network setup is fundamental to how PSC routes private traffic.

Limitations

• Cloud SQL's infrastructure doesn't currently support adding additional network interfaces or modifying the connectivity settings of existing instances.
• Retroactively enabling PSC would require substantial changes to the underlying Cloud SQL instance, which isn't possible.

Workarounds

While you cannot directly enable PSC on an existing instance, here are some options depending on your circumstances:

1. Create a New Instance with PSC:

   • Create a new Cloud SQL instance with PSC enabled.
   • Migrate your data from the existing instance to the new one using database replication or export/import tools.
   • Make sure you consider potential downtime during this migration.

2. Use an IP Whitelist:

   • If you absolutely cannot migrate to a new instance, carefully control access to your existing Cloud SQL instance using an IP whitelist.
   • This is less secure than PSC as it relies on IP-level access control, but it might be viable in some scenarios.

Important Considerations

• Downtime: The migration approach (#1) usually involves some downtime. Assess this impact against your application's requirements.
• Security: Always prioritize using PSC whenever possible due to its enhanced security compared to relying on IP whitelisting.

[kronus86]

Thanks a lot for your reply. I am following this guide (https://cloud.google.com/sql/docs/postgres/connect-multiple-vpcs#custom-route) which suggests other options like setting up Auth proxy or Intermediate proxy (socks5). 

Do you think either of those will be helpful to get external client access database securely. Note I need to setup those because I need multiple VPC connection to the database and was hoping if any of those solution would work for External client access as well. Thanks.

[ms4446]

You're on the right track with considering using either an Auth proxy or an Intermediate proxy (socks5) for setting up external client access to your Cloud SQL database securely.

However, it's important to note that:

Auth proxy is not recommended for external client access because it requires exposing the proxy to the public internet, which could introduce security risks.

On the other hand, Intermediate proxy (socks5) can be a viable option for external client access if you deploy the proxy in a secure environment and restrict access to authorized clients only.

Here are the steps on how to use Intermediate proxy (socks5) for external client access to a private Cloud SQL instance:

1. Deploy an intermediate proxy (socks5) in a VPC that has peering with the VPC where the Cloud SQL instance is located.
2. Configure the intermediate proxy to forward traffic to the Cloud SQL instance.
3. Grant access to the intermediate proxy only to authorized clients.
4. Configure your external clients to connect to the intermediate proxy using the socks5 protocol.

For more details on how to set up and configure an intermediate proxy (socks5), please refer to the Google Cloud documentation: https://cloud.google.com/sql/docs/postgres/connect-multiple-vpcs#custom-route

Remember that security is paramount when dealing with external client access. Make sure to follow best practices and implement appropriate security measures to protect your Cloud SQL instance.

[kronus86]

Thanks. Another question: From the docs it is not clear how can I connect CloudRun (in VPC A) to send request to SOCKS proxy in (VPC B) to route to Database. The documentation talks about installing Auth Proxy on Client, however that won't be feasible on the CloudRun for us.

[ms4446]

Yes, this is true. The provided link focuses on local clients using the Auth Proxy, which wouldn't apply to your Cloud Run (VPC A) to SOCKS proxy (VPC B) scenario. Here's how you can enable this type of connection:

Understanding the Limitation

Directly integrating a Cloud Run service with a SOCKS proxy isn't as straightforward as the Cloud SQL Auth Proxy, since there's no built-in mechanism for this type of proxy handling within the Cloud Run environment.

Solutions

1. Sidecar Container:

   • Package a SOCKS proxy client into a sidecar container within your Cloud Run deployment.
   • This sidecar would handle communication with the SOCKS proxy in VPC B.
   • Your main application container would direct database requests to the local sidecar container, which would then forward them appropriately.
   • Considerations:
     • Increased resource usage due to the sidecar.
     • Potential code changes to your application if it's not designed to use a local proxy.

2. Network-Level Proxy (If Feasible):

   • If you have control over the network configuration, you could investigate deploying a network-level SOCKS proxy that Cloud Run traffic can be routed through transparently.
   • This depends heavily on your specific network setup and may require custom routing or potentially solutions like Istio for finer-grained control.
   • Considerations:
     • Network complexity overhead.
     • The proxy becomes a central point, so scaling and security require attention.

Important Notes:

• VPC Peering: Regardless of the approach, ensure VPC Peering exists between VPC A (Cloud Run) and VPC B (SOCKS Proxy).
• Example Code: If you opt for the sidecar approach, having a sample code demonstrating a SOCKS proxy client (in your relevant programming language) within the sidecar would be helpful.

Security:

• Authentication/Authorization: Implement robust access controls to the SOCKS proxy to ensure only the Cloud Run service can use it.
• Data Encryption: Always prioritize in-transit data encryption between Cloud Run and the proxy when handling database traffic, even within your VPCs.

[kronus86]

Update: After going through all the options we have settled for HA VPN based solution with Custom route advertisement in Cloud Router. We tested it and we can connect our VM machines in different Org/Project to the database now.

@ms4446 : We have not been able to connect CloudRun machines using the above method. Can you please confirm if the HA VPN + Custom Route Advertisement will work for CloudRun as well. We have created "Serverless VPC Access" for our CloudRun machines. If yes, would appreciate if you can confirm the steps.