and activate this user while on the "secondary" in tests
Canvas uses read-only secondary database replicas, but before now,
GuardRail.activate(:secondary) had no effect in specs. The result
is that specs wouldn't catch attempts to write to a secondary,
and the error would be discovered in production, often requiring
a hotfix.
This patchset sets up a migration that creates a `canvas_readonly_user`
in the database and sets up SELECT permissions for it in each
shard's schema. (The migration does nothing in production.)
It also stubs out GuardRail in specs to run
`SET ROLE canvas_readonly_user` when activating the secondary,
and `RESET ROLE` when returning to the primary.
test plan:
- specs pass (this PS includes specs that attempt to write to
the secondary and verify the correct error is raised)
- use the read-only user in development by adding the following
to the development section in config/database.yml:
secondary:
username: canvas_readonly_user
then try to write to the secondary in the rails console and
ensure you get a permission denied error. for example,
GuardRail.activate(:secondary) { User.create! }
should result in
PG::InsufficientPrivilege: ERROR: permission denied for
table users (ActiveRecord::StatementInvalid)
flag = none
closes LS-2818
Change-Id: Ibfa75af821eb7f5d65f6b26aea03417378ab255a
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/161086
QA-Review: Isaac Moore <isaac.moore@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
Jeremy Stanley