Ensure queues are set up for non-coordinator nodes

Allows a runner to operate on every possible node, not just
coordinators, as OSDs or other things could be on any node.

Also add more comments.

api-daemon/pvcapid/flaskapi.py

@@ -26,6 +26,10 @@ from flask_restful import Resource, Api, reqparse, abort
 from celery import Celery
 from kombu import Queue
 
+from daemon_lib.common import getPrimaryNode
+from daemon_lib.zkhandler import ZKConnection
+from daemon_lib.node import get_list as get_node_list
+
 from pvcapid.Daemon import config, strtobool, API_VERSION
 
 import pvcapid.helper as api_helper
@@ -57,17 +61,24 @@ app.config["CELERY_RESULT_BACKEND"] = "db+postgresql://{}:{}@{}:{}/{}".format(
     config["database_port"],
     config["database_name"],
 )
-# Set up queue routing
+
+# Set up Celery queues
 app.config["CELERY_DATABASE_ENGINE_OPTIONS"] = {"echo": True}
+
+
+@ZKConnection(config)
+def get_all_nodes(zkhandler):
+    _, all_nodes = get_node_list(zkhandler, None)
+    return [n["name"] for n in all_nodes]
+
+
 app.config["CELERY_QUEUES"] = tuple(
-    [Queue(h, routing_key=f"{h}.#") for h in config["coordinators"]]
+    [Queue(h, routing_key=f"{h}.#") for h in get_all_nodes()]
 )
 
 
+# Set up Celery queue routing
 def route_task(name, args, kwargs, options, task=None, **kw):
-    from daemon_lib.common import getPrimaryNode
-    from daemon_lib.zkhandler import ZKConnection
-
     @ZKConnection(config)
     def get_primary_node(zkhandler):
         return getPrimaryNode(zkhandler)
@@ -75,8 +86,10 @@ def route_task(name, args, kwargs, options, task=None, **kw):
     print("----")
     print(f"Incoming Celery task: '{name}' with args {args}, kwargs {kwargs}")
 
+    # If an explicit routing_key is set and it's in the kwargs of the function, use it to set the queue
     if options["routing_key"] != "default" and options["routing_key"] in kwargs.keys():
         run_on = kwargs[options["routing_key"]]
+    # Otherwise, use the primary node
     else:
         run_on = get_primary_node()
 
@@ -122,7 +135,6 @@ app.register_blueprint(blueprint)
 celery = Celery(app.name, broker=app.config["CELERY_BROKER_URL"])
 celery.conf.update(app.config)
 
-
 #
 # Custom decorators
 #