[ENTERPRISE-1418] Add support for plain JWT authentication

[llam15]

resolves #1079
resolves #726
docs dbt-labs/docs.getdbt.com/#

Problem

• Today, the dbt-snowflake adapter only supports Snowflake OAuth, where the Client ID/Secret belong to a Snowflake OAuth Client, and the token property is expected to be a refresh token, and the adapter will automatically perform the refresh token flow with it.

Solution

• This PR introduces a new authenticator type, jwt
• When authenticator is set to jwt, the token attribute will be treated as a plain JWT token, and passed directly into the snowflake connect method.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

Manual Testing

Spun up a dbt project and validated that dbt run, dbt test, and dbt build pass with the following profile:

dbt_snowflake_test:
  target: dev
  outputs:
    dev:
      type: snowflake
      account: cmvgrnf-dbt_infra_sandbox

      authenticator: jwt
      token: <REDACTED. Token obtained from an OAuth Flow with Okta, and Snowflake is configured to accept this token>

      role: external_oauth_testing
      database: llam_dbt_snowflake_testing
      warehouse: llam_dbt_snowflake_testing_wh
      schema: raw
      threads: 4
      client_session_keep_alive: False

      # optional
      connect_retries: 0 # default 0
      connect_timeout: 10 # default: 10
      retry_on_database_errors: False # default: false
      retry_all: False  # default: false
      reuse_connections: False # default: false

dbt-build.mov

dbt-run.mov

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the dbt-snowflake contributing guide.

[gcs272]

I'm not super up to speed on exhaustive adapter testing, but lgtm

[nm0s]

LGTM, but I'll let someone from the adapters team give the approval