Re:App Engine’s New Go 1.11 Runtime
by chrisbroadfoot on Tuesday October 16, 2018 @05:27PM
(#18233437)
Notable, though, that this new runtime better supports connecting to Postgres instances through the unix socket (/cloudsql/).
(GCP Gopher)
either you whitelisted your ips or you used the proxy (which go appengine could already use).
so with go you just needed to use https://github.com/GoogleCloudPlatform/cloudsql-proxy which means you just need to change the query string.
however a new feature is emerging where you can have a private ip that is connected to your internal services, however it is still a beta feature.
Source: myself, but not a googler, just a regular user