Google Spanner: JDBC Connection Strings?

Question

While Spanner looks exciting, the documentation for the Simba JDBC driver (included in the download links here: https://cloud.google.com/spanner/docs/partners/drivers) are relatively sparse, especially when compared to the documentation for the Simba JDBC BigQuery driver (https://cloud.google.com/bigquery/partners/simba-drivers/).

In particular, the documentation only mentions one connection string:

jdbc:cloudspanner://localhost;Project=simba-cloudspanner- jdbc;Instance=test-instance;Database=example-db

... there is no information about how to specify, for example, a service account and its p12 credentials or a path to a JSON file, which many Google Cloud services use.

Can anyone share JDBC connection strings or other setup details they have successfully used to connect to the service? I have tried, for example, setting the environment variable GOOGLE_APPLICATION_CREDENTIALS and providing a JDBC string in the same style as above, but to no avail.

Ideally, I would like to use a combination of instance id, project name, database name, a service account email, and a p12 file, but am open to other authentication options.

EDIT: When attempting the GOOGLE_APPLICATION_CREDENTIALS strategy, I generated this log file, in case it might be of any help https://gist.github.com/aryeh-looker/e6b1b1617d301f0a247463216c96535d

Answer 1

Double-checked my work, and it looks like I am in fact able to connect with a connection string as above and by setting the environment variable GOOGLE_APPLICATION_CREDENTIALS. Would be ideal to have some other options and documentation is still a bit spotty (no mention of the environment variable), so more information could be ideal.

This is a semi-workable solution. It suffers from the fact that you cannot have multiple connections with different service accounts in the same process.

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EDIT 2: This does not seem to work. I get errors about the instance not being specified when pointing to a JSON file.

EDIT: looks like with the latest release of the Spanner driver, there is a way to do this.

The latest release of the driver (1.0.4.1005) appears to support an optional JDBC parameter PvtKeyPath which takes a path to your private key as opposed to having to set the GOOGLE_APPLICATION_CREDENTIALS variable. Worth a look.

From the included PDF documentation:

So you will have a URL like: jdbc:cloudspanner://;Project=...;PvtKeyPath=/path/to/credentials.json

Answer 2

As the JDBC Driver supplied by Google is severely limited (does not support DML and DDL statemetns), I have written my own JDBC Driver. The driver is designed to work with JPA/Hibernate-enabled applications. The driver can be found here: https://github.com/olavloite/spanner-jdbc

This driver supports the same kind of URL's as the driver supplied by Google, including the PvtKeyPath property. It is still BETA, but I already use it for one of my own applications.