Support Postgres role scope

[shooka]

First of all, I'm super happy with DBT.

It's a great tool and it rids my team and I from the tedious and error-prone flow that we used to have before switching.

Since we're multiple people working on the same project, we need to align the access rights before creating new objects in our Postgres schemas.

Our current solution is to set two pre-hooks (one for models and one for seeds) that look like this:

set role data_engineer

This works ok, but your documentation states that it's possible to set a role in the dbt profile for Snowflake connections. I would like to be able to do that in Postgres as well.

This PR partially fixes #1955 as I haven't implemented the Redshift part of the issue. I'll do that when I get more familiar with Redshift if no one beats me to it.

[cla-bot]

Thanks for your pull request, and welcome to our community! We require contributors to sign our Contributor License Agreement and we don't seem to have your signature on file. Check out this article for more information on why we have a CLA.

In order for us to review and merge your code, please submit the Individual Contributor License Agreement form attached above above. If you have questions about the CLA, or if you believe you've received this message in error, don't hesitate to ping @drewbanin.

CLA has not been signed by users: @shooka

[shooka]

I've just signed the CLA.

[drewbanin]

Thanks for opening this PR @shooka! @cla-bot check

This change looks good to me. I think Redshift supports groups instead of roles, so I'm unsure if any action is actually required on this front for Redshift? Let me know if you think differently.

I'm going to kick off the rest of the test suite here! Will follow up when those tests have finished running :)

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[shooka]

I'm unsure if any action is actually required on this front for Redshift?

This might be the case 👍 I don't know Redshift well enough to say.

[drewbanin]

This LGTM! Nice work @shooka :)

Closing #1955 as no Redshift action is required here