avoid MD5 for FIPS support

This is a temporary patch until upstream fix is merged, see
que-rb/que#437

Author: akostadinov

db/migrate/20251008141931_replace_md5_with_hashtext_in_que_job_notify.rb

@@ -0,0 +1,134 @@
+class ReplaceMd5WithHashtextInQueJobNotify < ActiveRecord::Migration[7.0]
+  # This fixes https://github.com/que-rb/que/pull/437
+  # Be careful on Que upgrade in case the final fix differed.
+
+  def up
+    Que.transaction do
+      Que.execute <<~SQL
+      CREATE OR REPLACE FUNCTION que_job_notify() RETURNS trigger AS $$
+        DECLARE
+          locker_pid integer;
+          sort_key json;
+        BEGIN
+          -- Don't do anything if the job is scheduled for a future time.
+          IF NEW.run_at IS NOT NULL AND NEW.run_at > now() THEN
+            RETURN null;
+          END IF;
+
+          -- Pick a locker to notify of the job's insertion, weighted by their number
+          -- of workers. Should bounce pseudorandomly between lockers on each
+          -- invocation, hence the hashtext-ordering, but still touch each one equally,
+          -- hence the modulo using the job_id.
+          SELECT pid
+          INTO locker_pid
+          FROM (
+            SELECT *, last_value(row_number) OVER () + 1 AS count
+            FROM (
+              SELECT *, row_number() OVER () - 1 AS row_number
+              FROM (
+                SELECT *
+                FROM public.que_lockers ql, generate_series(1, ql.worker_count) AS id
+                WHERE
+                  listening AND
+                  queues @> ARRAY[NEW.queue] AND
+                  ql.job_schema_version = NEW.job_schema_version
+                ORDER BY hashtext(pid::text || id::text)
+              ) t1
+            ) t2
+          ) t3
+          WHERE NEW.id % count = row_number;
+
+          IF locker_pid IS NOT NULL THEN
+            -- There's a size limit to what can be broadcast via LISTEN/NOTIFY, so
+            -- rather than throw errors when someone enqueues a big job, just
+            -- broadcast the most pertinent information, and let the locker query for
+            -- the record after it's taken the lock. The worker will have to hit the
+            -- DB in order to make sure the job is still visible anyway.
+            SELECT row_to_json(t)
+            INTO sort_key
+            FROM (
+              SELECT
+                'job_available' AS message_type,
+                NEW.queue       AS queue,
+                NEW.priority    AS priority,
+                NEW.id          AS id,
+                -- Make sure we output timestamps as UTC ISO 8601
+                to_char(NEW.run_at AT TIME ZONE 'UTC', 'YYYY-MM-DD"T"HH24:MI:SS.US"Z"') AS run_at
+            ) t;
+
+            PERFORM pg_notify('que_listener_' || locker_pid::text, sort_key::text);
+          END IF;
+
+          RETURN null;
+        END
+      $$
+      LANGUAGE plpgsql;
+      SQL
+    end
+  end
+
+  def down
+    Que.transaction do
+      Que.execute <<~SQL
+      CREATE OR REPLACE FUNCTION que_job_notify() RETURNS trigger AS $$
+        DECLARE
+          locker_pid integer;
+          sort_key json;
+        BEGIN
+          -- Don't do anything if the job is scheduled for a future time.
+          IF NEW.run_at IS NOT NULL AND NEW.run_at > now() THEN
+            RETURN null;
+          END IF;
+
+          -- Pick a locker to notify of the job's insertion, weighted by their number
+          -- of workers. Should bounce pseudorandomly between lockers on each
+          -- invocation, hence the md5-ordering, but still touch each one equally,
+          -- hence the modulo using the job_id.
+          SELECT pid
+          INTO locker_pid
+          FROM (
+            SELECT *, last_value(row_number) OVER () + 1 AS count
+            FROM (
+              SELECT *, row_number() OVER () - 1 AS row_number
+              FROM (
+                SELECT *
+                FROM public.que_lockers ql, generate_series(1, ql.worker_count) AS id
+                WHERE
+                  listening AND
+                  queues @> ARRAY[NEW.queue] AND
+                  ql.job_schema_version = NEW.job_schema_version
+                ORDER BY md5(pid::text || id::text)
+              ) t1
+            ) t2
+          ) t3
+          WHERE NEW.id % count = row_number;
+
+          IF locker_pid IS NOT NULL THEN
+            -- There's a size limit to what can be broadcast via LISTEN/NOTIFY, so
+            -- rather than throw errors when someone enqueues a big job, just
+            -- broadcast the most pertinent information, and let the locker query for
+            -- the record after it's taken the lock. The worker will have to hit the
+            -- DB in order to make sure the job is still visible anyway.
+            SELECT row_to_json(t)
+            INTO sort_key
+            FROM (
+              SELECT
+                'job_available' AS message_type,
+                NEW.queue       AS queue,
+                NEW.priority    AS priority,
+                NEW.id          AS id,
+                -- Make sure we output timestamps as UTC ISO 8601
+                to_char(NEW.run_at AT TIME ZONE 'UTC', 'YYYY-MM-DD"T"HH24:MI:SS.US"Z"') AS run_at
+            ) t;
+
+            PERFORM pg_notify('que_listener_' || locker_pid::text, sort_key::text);
+          END IF;
+
+          RETURN null;
+        END
+      $$
+      LANGUAGE plpgsql;
+      SQL
+    end
+  end
+end

db/structure.sql

@@ -114,7 +114,7 @@ CREATE FUNCTION public.que_job_notify() RETURNS trigger
 
     -- Pick a locker to notify of the job's insertion, weighted by their number
     -- of workers. Should bounce pseudorandomly between lockers on each
-    -- invocation, hence the md5-ordering, but still touch each one equally,
+    -- invocation, hence the hashtext-ordering, but still touch each one equally,
     -- hence the modulo using the job_id.
     SELECT pid
     INTO locker_pid
@@ -129,7 +129,7 @@ CREATE FUNCTION public.que_job_notify() RETURNS trigger
             listening AND
             queues @> ARRAY[NEW.queue] AND
             ql.job_schema_version = NEW.job_schema_version
-          ORDER BY md5(pid::text || id::text)
+          ORDER BY hashtext(pid::text || id::text)
         ) t1
       ) t2
     ) t3
@@ -1529,6 +1529,7 @@ INSERT INTO "schema_migrations" (version) VALUES
 ('20230629131935'),
 ('20230703133544'),
 ('20230703134109'),
-('20230704131552');
+('20230704131552'),
+('20251008141931');