Hi Antonin, First of all, thank you so much for taking the time to review my patch. I'll answer your questions in reverse order:
The "unsafe_tests" directory is where the pre-existing role tests were located. According to the readme of the "unsafe_tests" directory, the tests contained within are not run during "make installcheck" because they could have side-effects that seem undesirable for a production installation. This seemed like a reasonable location as the new tests that this patch introduces also modifies the "state" of the database cluster by adding, modifying, and removing roles & databases (including template1). Regarding roles_is_member_of(), the nuance is that role "A" in your example would only be considered a member of role "B" (and by extension role "C") when connected to the database in which "A" was granted database-specific membership to "B". Conversely, when connected to any other database, "A" would not be considered to be a member of "B". This patch is designed to solve the scenarios in which one may want to grant constrained access to a broader set of privileges. For example, membership in "pg_read_all_data" effectively grants SELECT and USAGE rights on everything (implicitly cluster-wide in today's implementation). By granting a role membership to "pg_read_all_data" within the context of a specific database, the grantee's read-everything privilege is effectively constrained to just that specific database (as membership within "pg_read_all_data" would not otherwise be held). A rebased version is attached. Thanks again! - Kenaniah On Wed, Jun 29, 2022 at 6:45 AM Antonin Houska <a...@cybertec.at> wrote: > Kenaniah Cerny <kenan...@gmail.com> wrote: > > > Attached is a newly-rebased patch -- would love to get a review from > someone whenever possible. > > I've picked this patch for a review. The patch currently does not apply to > the > master branch, so I could only read the diff. Following are my comments: > > * I think that roles_is_member_of() deserves a comment explaining why the > code > that you moved into append_role_memberships() needs to be called twice, > i.e. once for global memberships and once for the database-specific ones. > > I think the reason is that if, for example, role "A" is a > database-specific > member of role "B" and "B" is a "global" member of role "C", then "A" > should > not be considered a member of "C", unless "A" is granted "C" explicitly. > Is > this behavior intended? > > Note that in this example, the "C" members are a superset of "B" members, > and thus "C" should have weaker permissions on database objects than > "B". What's then the reason to not consider "A" a member of "C"? If "C" > gives its members some permissions of "B" (e.g. "pg_write_all_data"), > then I > think the roles hierarchy is poorly designed. > > A counter-example might help me to understand. > > * Why do you think that "unsafe_tests" is the appropriate name for the > directory that contains regression tests? > > I can spend more time on the review if the patch gets rebased. > > -- > Antonin Houska > Web: https://www.cybertec-postgresql.com >
database-role-memberships-v9.patch
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