Fix config update detection

We are supposed to update zuul/nodepool when the relevant secrets
are updated.  We do that by subscribing to changes on all secrets
in the system, then check to see if they are ones that we're watching
and if so, run the appropriate operator methods.

We only updated the list of secrets to watch on startup, which means
that from a clean start where a zuul was added, we would not add
the new secrets to our list.  This change updates the list after every
time that the zuul resource is created or updated.

Change-Id: Ib6191367eb2596eba560b9c570140f33866c005f

zuul_operator/operator.py

@@ -26,17 +26,17 @@ ConfigResource = collections.namedtuple('ConfigResource', [
     'attr', 'namespace', 'zuul_name', 'resource_name'])
 
 
-@kopf.on.startup()
-def startup(memo, **kwargs):
+def memoize_secrets(memo, logger):
     # (zuul_namespace, zuul) -> list of resources
-    memo.config_resources = {}
+    memo.config_resources.clear()
+    new_resources = {}
     # lookup all zuuls and update configmaps
 
     api = pykube.HTTPClient(pykube.KubeConfig.from_env())
     for namespace in objects.Namespace.objects(api):
         for zuul in objects.ZuulObject.objects(api).filter(
                 namespace=namespace.name):
-            resources = memo.config_resources.\
+            resources = new_resources.\
                 setdefault((namespace.name, zuul.name), [])
             # Zuul tenant config
             secret = zuul.obj['spec']['scheduler']['config']['secretName']
@@ -49,6 +49,22 @@ def startup(memo, **kwargs):
             res = ConfigResource('spec.launcher.config.secretName',
                                  namespace.name, zuul.name, secret)
             resources.append(res)
+    # Mutate the global instance
+    memo.config_resources.clear()
+    memo.config_resources.update(new_resources)
+
+
+@kopf.on.startup()
+def startup(memo, logger, **kwargs):
+    # Operator handlers (like this one) get a single global memo
+    # object; resource handlers (like update) get a memo object for
+    # that specific resource with items shallow-copied from the global
+    # memo.
+    #
+    # Initialize a dictionary here that we will mutate (but never
+    # overwrite) in all the handlers.
+    memo.config_resources = {}
+    memoize_secrets(memo, logger)
 
 
 @kopf.on.update('secrets')
@@ -74,7 +90,7 @@ def update_secret(name, namespace, logger, memo, new, **kwargs):
 
 
 @kopf.on.create('zuuls', backoff=10)
-def create_fn(spec, name, namespace, logger, **kwargs):
+def create_fn(spec, name, namespace, logger, memo, **kwargs):
     logger.info(f"Create zuul {namespace}/{name}")
 
     zuul = Zuul(namespace, name, logger, spec)
@@ -95,12 +111,13 @@ def create_fn(spec, name, namespace, logger, **kwargs):
     zuul.write_zuul_conf()
     zuul.create_zuul()
 
+    memoize_secrets(memo, logger)
     # We can set a status with something like:
     # return {'message': 'hello world'}
 
 
 @kopf.on.update('zuuls', backoff=10)
-def update_fn(name, namespace, logger, old, new, **kwargs):
+def update_fn(name, namespace, logger, old, new, memo, **kwargs):
     logger.info(f"Update zuul {namespace}/{name}")
 
     old = old['spec']
@@ -145,6 +162,8 @@ def update_fn(name, namespace, logger, old, new, **kwargs):
     if spec_changed:
         zuul.create_zuul()
 
+    memoize_secrets(memo, logger)
+
 
 class ZuulOperator:
     def run(self):