How to send query to Cloud SQL for PostgreSQL

[uS-aito]

Hello,

We are using Cloud SQL for PostgreSQL and would like to do some scaling based on the number of data in a table.

Normally, the connection to Cloud SQL is made by injecting a SQL Proxy as a sidecar and connecting to localhost (127.0.01).

How can we achieve this in KEDA?
Do I just add the sidecar to the Deployment to be scaled? Or do I need to add a sidecar to the keda-operator-metrics-apiserver Pod by some means?

Thank you.

[zroubalik]

Hi, I am not that much familiar with Cloud SQL, but IMHO it should work if you add the sidecar to the both KEDA Operator and Metrics Apiserver (you need to add it to the both Deployments).
I am curious to hear the result :)

[uS-aito]

Thanks for replying.

After reading your reply and reading the source code of KEDA, I came to the same conclusion.
In other words, I thought that I need to inject sidecar into both pods.
I just tried scaling after injecting sidecar into both pods, and it worked fine.

Thanks for your help.

[kokizzu]

what sidecar @uS-aito ?
cloudsql postgres -> metricserver -> keda? because keda-postgres cannot have cloudsql's certificate injected?

[kokizzu]

or the sidecar is to proxy requests between keda and cloudsql, so the cloudsql certs is on the sidecar?

[uS-aito]

I'm not familiar with github discussion, how do I mark this topic as answerd?

[zroubalik]

I did that :)

[uS-aito]

Thank you very much!

[Joshua-Hager]

Checking in 4 years later to let people know that this solution still works. The following steps worked for me:

• Download and modify the release YAML file with the Cloud SQL Proxy Sidecar for the Operator container and the Metrics API Server container.
• Apply the modified YAML file to your cluster. You may need to use the --server-side option when applying due to the length of the file i.e. kubectl apply --server-side -f /path/to/keda.yml.
• When writing the MySQL scaler, use the password authentication method and pass the parameters individually (the connection string method resulted in a TCP dial error for me).
• Bind the keda-operator service account to a GCP service account with the correct IAM permissions to access your Cloud SQL instance or change the name of the of the keda-operator service account to the name of a service account that already has the correct permissions.

These steps allowed the MySQL scaler to query the Cloud SQL instance.