let the controller list the agent-permissions bucket so the grant re-mirror runs

swarm-nats-auth/src/policy.rs

@@ -802,6 +802,16 @@ impl Policy {
             format!("$JS.API.CONSUMER.CREATE.{agent_status}"),
             format!("$JS.API.CONSUMER.CREATE.{agent_status}.>"),
         ]);
+        // The permissions bucket, listed only: the controller's five-minute
+        // re-mirror calls `keys()`, whose ephemeral ordered consumer has no
+        // name, so the bare create subject is the one subject it needs. No
+        // `.>` form: that is for named consumers, and none is created here.
+        // Open, read and write of the bucket are already covered by
+        // `STREAM.INFO.*`, `DIRECT.GET.*.>` and `$KV.*.>` above.
+        subjects.push(format!(
+            "$JS.API.CONSUMER.CREATE.{}",
+            swarm_wire::agent_permissions::STREAM
+        ));
         subjects
     }
 }
@@ -852,6 +862,29 @@ mod tests {
         assert!(!subjects.contains(&format!("$JS.API.STREAM.DELETE.{s}")));
     }
 
+    #[test]
+    fn the_reader_can_list_the_agent_permissions_bucket_and_no_other_stream() {
+        let subjects = policy().reader_subjects();
+        let s = swarm_wire::agent_permissions::STREAM;
+        // The bare form is what `keys()` needs: its ephemeral consumer has
+        // no name.
+        assert!(subjects.contains(&format!("$JS.API.CONSUMER.CREATE.{s}")));
+        // Negative controls: the grant names this one stream, and holds no
+        // wildcard, `.>` form or delete/info subject for it.
+        assert!(!subjects.contains(&"$JS.API.CONSUMER.CREATE.*".to_owned()));
+        assert!(!subjects.contains(&format!("$JS.API.CONSUMER.CREATE.{s}.>")));
+        assert!(!subjects.contains(&format!("$JS.API.CONSUMER.CREATE.{s}.*")));
+        assert!(
+            !subjects
+                .iter()
+                .any(|x| x.starts_with("$JS.API.CONSUMER.DELETE"))
+        );
+        assert!(
+            !subjects.contains(&"$JS.API.CONSUMER.CREATE.KV_unrelated".to_owned()),
+            "an unrelated stream must not be creatable"
+        );
+    }
+
     #[test]
     fn no_hive_may_write_another_role_s_agent_status() {
         // A hive publishes its *own* agents' status under