fix: Treat empty runtime namespaces as All Namespaces mode (#658)

If the runtime configuration specifies an empty string as the namespaces to watch, we should treat that as all namespaces mode, mainly because that's how OLM signifies that an operator should watch all namespaces.

An empty string is treated the same as unset by the configuration parser, so we need to set a default on the field so we can explicitly check for it being unset, to determine if the empty string was used.

Fixes #656

Signed-off-by: James Hewitt <james.hewitt@uk.ibm.com>

core/runtime/src/main/java/io/quarkiverse/operatorsdk/runtime/ConfigurationServiceRecorder.java

@@ -1,5 +1,8 @@
 package io.quarkiverse.operatorsdk.runtime;
 
+import static io.javaoperatorsdk.operator.api.reconciler.Constants.DEFAULT_NAMESPACES_SET;
+import static io.quarkiverse.operatorsdk.runtime.Constants.QOSDK_USE_BUILDTIME_NAMESPACES_SET;
+
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Optional;
@@ -55,9 +58,22 @@ public Supplier<QuarkusConfigurationService> configurationServiceSupplier(Versio
                 c.setRetryConfiguration(null);
             }
 
-            // if despite all of this, we still haven't set the namespaces, use the operator-level default if it exists
+            // if the namespaces weren't set as an annotation, use the operator-level configuration if it exists
             if (!c.isWereNamespacesSet()) {
-                runTimeConfiguration.namespaces.ifPresent(ns -> c.setNamespaces(new HashSet<>(ns)));
+                // The namespaces field has a default value so that we are able to detect if the configuration value is set to "".
+                // Setting the value to "" will reset the configuration and result in an empty Optional.
+                // Not setting the value at all will result in the default being applied, which we can test for.
+                if (runTimeConfiguration.namespaces.isPresent()) {
+                    final var runtimeNamespaces = new HashSet<>(runTimeConfiguration.namespaces.get());
+                    // If it's not the default value, use it because it was set.
+                    // If it is the default value, ignore it and let any build time config be used.
+                    if (!QOSDK_USE_BUILDTIME_NAMESPACES_SET.equals(runtimeNamespaces)) {
+                        c.setNamespaces(runtimeNamespaces);
+                    }
+                } else {
+                    // Value has been explicitly reset (value was empty string), use all namespaces mode
+                    c.setNamespaces(DEFAULT_NAMESPACES_SET);
+                }
             }
         });
 

core/runtime/src/main/java/io/quarkiverse/operatorsdk/runtime/Constants.java

@@ -0,0 +1,14 @@
+package io.quarkiverse.operatorsdk.runtime;
+
+import java.util.Collections;
+import java.util.Set;
+
+public final class Constants {
+    private Constants() {
+    }
+
+    public static final Set<String> QOSDK_USE_BUILDTIME_NAMESPACES_SET = Collections
+            .singleton(Constants.QOSDK_USE_BUILDTIME_NAMESPACES);
+
+    public static final String QOSDK_USE_BUILDTIME_NAMESPACES = "QOSDK_USE_BUILDTIME_NAMESPACES";
+}

core/runtime/src/main/java/io/quarkiverse/operatorsdk/runtime/RunTimeOperatorConfiguration.java

@@ -14,6 +14,8 @@
  */
 package io.quarkiverse.operatorsdk.runtime;
 
+import static io.quarkiverse.operatorsdk.runtime.Constants.QOSDK_USE_BUILDTIME_NAMESPACES;
+
 import java.time.Duration;
 import java.util.List;
 import java.util.Map;
@@ -59,7 +61,10 @@ public class RunTimeOperatorConfiguration {
      * specified by the kube config file the operator uses.
      * </p>
      */
-    @ConfigItem
+    // We use a default here so that we are able to detect if the configuration value is set to "". Setting the value to "" will
+    // reset the configuration and result in an empty Optional, but not setting the value at all will result in the default being
+    // applied.
+    @ConfigItem(defaultValue = QOSDK_USE_BUILDTIME_NAMESPACES)
     public Optional<List<String>> namespaces;
 
     /**

docs/modules/ROOT/pages/includes/quarkus-operator-sdk.adoc

@@ -319,7 +319,7 @@ ifndef::add-copy-button-to-env-var[]
 Environment variable: `+++QUARKUS_OPERATOR_SDK_NAMESPACES+++`
 endif::add-copy-button-to-env-var[]
 --|list of string 
-|
+|`QOSDK_USE_BUILDTIME_NAMESPACES`
 
 
 a| [[quarkus-operator-sdk_quarkus.operator-sdk.concurrent-workflow-threads]]`link:#quarkus-operator-sdk_quarkus.operator-sdk.concurrent-workflow-threads[quarkus.operator-sdk.concurrent-workflow-threads]`