I've solved the same problem but used Kubernetes namespaces instead. Each customer gets their own namespace and a namespace is locked down in terms of networki

I've solved the same problem but used Kubernetes namespaces instead. Each customer gets their own namespace and a namespace is locked down in terms of networking and I deploy Postgres in each namespace using the Postgres operator. I've built an operator for my app, so deploying the app into a namespace is as simple as deploying the manifest.