Add user_id to snowplow event tracking

blocked by https://gitlab.com/gitlab-org/telemetry/issues/97

Problem

  • Now that we're on GitLab internal Snowplow infra, we can start sending more sensitive data.
  • The critical piece we need is the user_id that's tied to the gitlab installation sent

Without this, the tracking isn't really useful. This is a high priority.

Proposal

Attach attribute called 'user_id' in Snowplow to the id of the user that's on the users table in the DB.

Result

Ability to track and improve upon highly important metrics such as explained here: https://gitlab.com/gitlab-org/telemetry/issues/57#note_190517245

Next steps (if any)

@tipyn how do we get this scheduled?

cc @jeremy @ebrinkman @eli_kastelein

Edited by Luca Kisielius