Google Cloud SQL connectivity from External network

Can/should Cloud SQL Auth Proxy be used for production applications?

Yes, you can use Cloud SQL Auth Proxy with production applications. If your application is also written in Go, then you can directly integrate the proxy as part of your application. Otherwise, you must set up a procedure for launching the proxy, such as at the system start.

Google Cloud SQL offers several layers of security:

• Cloud SQL Auth Proxy
• IP Whitelisting (similar to a firewall)
• Encrypted SSL connections with the option to require all connections use a certificate
• VPC Service Controls
• Cloud IAM Integration

Research the various options and decide which method or combination of methods meet your requirements.