<p>So, I created a postgreSQL instance in Google Cloud, and I have a Kubernetes Cluster with containers that I would like to connect to it. I know that the cloud sql proxy sidecar is one method, but the documentation says that I should be able to connect to the private IP as well.</p>

<p>I notice that a VPC peering connection was automatically created for me. It's set for a destination network of 10.108.224.0/24, which is where the instance is, with a "Next hop region" of us-central1, where my K8s cluster is. </p>

<p>And yet when I try the private IP via TCP on port 5432, I time out. I see nothing in the documentation about have to modify firewall rules to make this work, but I tried that anyway, finding the firewall interface in GCP rather clumsy and confusing compared with writing my own rules using iptables, but my attempts failed.</p>

<p>Beyond going to the cloud sql sidecar, does anyone have an idea why this would not work?</p>

<p>Thanks. </p>

<p>In the end, the simplest thing to do was to just use the google cloud sql proxy. As opposed to a sidecar, I have multiple containers needing db access so I put the proxy into my cluster as its own container with a service, and it seems to just work. </p>
