Sopport socket:// URLs, needed for AppEngine+CloudSQL use

[RP-3]

Desired Behavior

• When following the official App Engine Postgres CloudSQL connection instructions here to connect to a Postgres instance via a public IP in the App Engine Standard Environment, I expect a socket:// connection string passed to Slonik to work.
• Currently, Slonik throws an the error [ERR_INVALID_URL]: Invalid URL, when given a connection string in any of the following forms:
  • socket://PASSWORD@/cloudsql/INSTANCE_CONNECTION_NAME/.s.PGSQL.5432?db=DB_NAME
  • socket://PASSWORD@/cloudsql/INSTANCE_CONNECTION_NAME?db=DB_NAME
  • socket://PASSWORD@/cloudsql/INSTANCE_CONNECTION_NAME/DB_NAME

Motivation

• Google App Engine recommends this as the default way to connect to CloudSQL, and it is also the only way to connect if the database has a public IP address or is in a different region to the client initiating a connection.
• Google/Firebase Cloud Functions only allow socket:// connections
• A variety of other reasons have been proposed in this issue, however, they advocate passing a full-blown connection object which is not strictly necessary for this use case
• Other issues imply that this previously worked, but was broken in subsequent updates.

Implementation

• @gajus has previously recommended a solution here.

[dbousamra]

Any further updates on this? This feature is preventing me from upgrading slonik

[gajus]

@mgreenw This was addressed by your PR, wasn't it?

#409

[mgreenw]

Yes, #409 should fix it! You need to url-encode the unix socket path, so the final connection uri should be passed like postgresql://<user>:<password>@%2Fcloudsql%2F<project-id>%3A<region-name>%3A<sql-instance>/<db-name>

v31.2.1

[gajus]

Thank you