Ensure all Sidekiq queues are always alive

mastodon.nix

@@ -36,6 +36,7 @@ let
   sidekiq-manager = pkgs.writers.writePython3 "sidekiq-manager" {} ''
     from itertools import permutations
     from subprocess import Popen
+    from time import sleep
 
 
     def sidekiq(queues, connections=16):
@@ -52,6 +53,17 @@ let
     queues = ['default', 'push', 'ingress']
     procs += [sidekiq(qs) for qs in permutations(queues)]
 
+    for p in procs:
+        sleep(1)
+        if p.poll():
+            # one of the queues is dead
+            break
+
+    # terminate the rest queues
+    for p in procs:
+        # https://github.com/sidekiq/sidekiq/wiki/Signals#term
+        p.terminate()
+
     for p in procs:
         p.wait()
   '';