From a9275b3d59b73e6a3b383d215d9e8f903bbbf1f1 Mon Sep 17 00:00:00 2001
From: Andrew Azores <aazores@redhat.com>
Date: Tue, 26 Nov 2024 14:51:37 -0500
Subject: [PATCH] refactor

---
 .../cryostat/discovery/KubeApiDiscovery.java  | 101 ++++++++++--------
 1 file changed, 55 insertions(+), 46 deletions(-)

diff --git a/src/main/java/io/cryostat/discovery/KubeApiDiscovery.java b/src/main/java/io/cryostat/discovery/KubeApiDiscovery.java
index 10134cf91..d5cd02f2e 100644
--- a/src/main/java/io/cryostat/discovery/KubeApiDiscovery.java
+++ b/src/main/java/io/cryostat/discovery/KubeApiDiscovery.java
@@ -110,42 +110,42 @@ public class KubeApiDiscovery implements ResourceEventHandler<Endpoints> {
                 @Override
                 protected HashMap<String, SharedIndexInformer<Endpoints>> initialize()
                         throws ConcurrentException {
-                    // TODO: add support for some wildcard indicating a single Informer for any
-                    // namespace that Cryostat has permissions to. This will need some restructuring
-                    // of how the namespaces within the discovery tree are mapped.
                     var result = new HashMap<String, SharedIndexInformer<Endpoints>>();
-                    kubeConfig
-                            .getWatchNamespaces()
-                            .forEach(
-                                    ns -> {
-                                        SharedIndexInformer<Endpoints> informer;
-                                        if (ALL_NAMESPACES.equals(ns)) {
-                                            informer =
-                                                    client.endpoints()
-                                                            .inAnyNamespace()
-                                                            .inform(
-                                                                    KubeApiDiscovery.this,
-                                                                    informerResyncPeriod
-                                                                            .toMillis());
-                                        } else {
-                                            informer =
+                    if (watchAllNamespaces()) {
+                        result.put(
+                                ALL_NAMESPACES,
+                                client.endpoints()
+                                        .inAnyNamespace()
+                                        .inform(
+                                                KubeApiDiscovery.this,
+                                                informerResyncPeriod.toMillis()));
+                    } else {
+                        kubeConfig
+                                .getWatchNamespaces()
+                                .forEach(
+                                        ns -> {
+                                            result.put(
+                                                    ns,
                                                     client.endpoints()
                                                             .inNamespace(ns)
                                                             .inform(
                                                                     KubeApiDiscovery.this,
                                                                     informerResyncPeriod
-                                                                            .toMillis());
-                                        }
-                                        result.put(ns, informer);
-                                        logger.debugv(
-                                                "Started Endpoints SharedInformer for namespace"
-                                                        + " \"{0}\" with resync period {1}",
-                                                ns, informerResyncPeriod);
-                                    });
+                                                                            .toMillis()));
+                                            logger.debugv(
+                                                    "Started Endpoints SharedInformer for namespace"
+                                                            + " \"{0}\" with resync period {1}",
+                                                    ns, informerResyncPeriod);
+                                        });
+                    }
                     return result;
                 }
             };
 
+    private boolean watchAllNamespaces() {
+        return kubeConfig.getWatchNamespaces().stream().anyMatch(ns -> ALL_NAMESPACES.equals(ns));
+    }
+
     void onStart(@Observes StartupEvent evt) {
         if (!enabled()) {
             return;
@@ -158,22 +158,26 @@ void onStart(@Observes StartupEvent evt) {
 
         logger.debugv("Starting {0} client", REALM);
         safeGetInformers();
-        resyncWorker.scheduleAtFixedRate(
-                () -> {
-                    try {
-                        logger.debug("Resyncing");
-                        notify(
-                                NamespaceQueryEvent.from(
-                                        kubeConfig.getWatchNamespaces().stream()
-                                                .filter(ns -> !ALL_NAMESPACES.equals(ns))
-                                                .toList()));
-                    } catch (Exception e) {
-                        logger.warn(e);
-                    }
-                },
-                0,
-                informerResyncPeriod.toMillis(),
-                TimeUnit.MILLISECONDS);
+        // TODO we should not need to force manual re-syncs this way - the Informer is already
+        // supposed to resync itself.
+        if (!watchAllNamespaces()) {
+            resyncWorker.scheduleAtFixedRate(
+                    () -> {
+                        try {
+                            logger.debug("Resyncing");
+                            notify(
+                                    NamespaceQueryEvent.from(
+                                            kubeConfig.getWatchNamespaces().stream()
+                                                    .filter(ns -> !ALL_NAMESPACES.equals(ns))
+                                                    .toList()));
+                        } catch (Exception e) {
+                            logger.warn(e);
+                        }
+                    },
+                    0,
+                    informerResyncPeriod.toMillis(),
+                    TimeUnit.MILLISECONDS);
+        }
     }
 
     void onStop(@Observes ShutdownEvent evt) {
@@ -323,11 +327,16 @@ public void handleQueryEvent(NamespaceQueryEvent evt) {
                 }
 
                 Stream<Endpoints> endpoints;
-                if (safeGetInformers().containsKey(namespace)) {
-                    endpoints = safeGetInformers().get(namespace).getStore().list().stream();
-                } else {
+                if (watchAllNamespaces()) {
                     endpoints =
-                            client.endpoints().inNamespace(namespace).list().getItems().stream();
+                            safeGetInformers().get(ALL_NAMESPACES).getStore().list().stream()
+                                    .filter(
+                                            ep ->
+                                                    Objects.equals(
+                                                            ep.getMetadata().getNamespace(),
+                                                            namespace));
+                } else {
+                    endpoints = safeGetInformers().get(namespace).getStore().list().stream();
                 }
                 Set<Target> observedTargets =
                         endpoints