Revert "use '-' for empty list for both variables"

This reverts commit 9d47322.

README.md

@@ -195,7 +195,8 @@ using the environment variables `CRYOSTAT_DISCOVERY_K8S_PORT_NAMES` and
 `CRYOSTAT_DISCOVERY_K8S_PORT_NUMBERS` respectively. Both of these accept
 comma-separated lists as values. Any observed `Endpoints` object with a name
 in the given list or a number in the given list will be taken as a connectable
-target application. To set either of the lists empty use the value `-`.
+target application. To set the names list to the empty list use `-`. To set the
+numbers list to the empty list use `0`.
 
 The second discovery mechanism is JDP (Java Discovery Protocol). This relies on
 target JVMs being configured with the JVM flags to enable JDP and requires the

src/main/java/io/cryostat/platform/internal/KubeApiPlatformStrategy.java

@@ -38,7 +38,8 @@
 
 class KubeApiPlatformStrategy implements PlatformDetectionStrategy<KubeApiPlatformClient> {
 
-    public static final String PORT_NAME_NUMBER_NONE = "-";
+    public static final String NO_PORT_NAME = "-";
+    public static final Integer NO_PORT_NUMBER = 0;
 
     protected final Logger logger;
     protected final Lazy<? extends AuthManager> authMgr;
@@ -70,13 +71,13 @@ public KubeApiPlatformClient getPlatformClient() {
         List<String> portNames =
                 Arrays.asList(env.getEnv(Variables.K8S_PORT_NAMES, "jfr-jmx").split(",")).stream()
                         .map(String::strip)
-                        .filter(n -> !PORT_NAME_NUMBER_NONE.equals(n))
+                        .filter(n -> !NO_PORT_NAME.equals(n))
                         .toList();
         List<Integer> portNumbers =
                 Arrays.asList(env.getEnv(Variables.K8S_PORT_NUMBERS, "9091").split(",")).stream()
                         .map(String::strip)
-                        .filter(n -> !PORT_NAME_NUMBER_NONE.equals(n))
                         .map(Integer::parseInt)
+                        .filter(n -> !NO_PORT_NUMBER.equals(n))
                         .toList();
         return new KubeApiPlatformClient(
                 getNamespaces(), portNames, portNumbers, createClient(), logger);