Adjust gradle base port by one (#58368)

When assigning ports for internal cluster tests, we use the gradle
worker id as an adjustment on the base port of 10300. In order to not go
outside the max port range, we modulo the worker id by 223. Since gradle
worker ids start at 1, we expect to never actually get the base port of
10300. However, as the gradle daemon lasts for longer, the module can
result in a value of 0, which cases the test to fail. This commit
adjusts the modulo to ensure the value is never 0.

closes #58279

Author: rjernst

test/framework/src/main/java/org/elasticsearch/test/ESTestCase.java

@@ -1409,8 +1409,17 @@ protected static int getBasePort() {
         // Ephemeral ports on Linux start at 32768 so we modulo to make sure that we don't exceed that.
         // This is safe as long as we have fewer than 224 Gradle workers running in parallel
         // See also: https://github.com/elastic/elasticsearch/issues/44134
-        final String workerId = System.getProperty(ESTestCase.TEST_WORKER_SYS_PROPERTY);
-        final int startAt = workerId == null ? 0 : Math.floorMod(Long.valueOf(workerId), 223);
+        final String workerIdStr = System.getProperty(ESTestCase.TEST_WORKER_SYS_PROPERTY);
+        final int startAt;
+        if (workerIdStr == null) {
+            startAt = 0; // IDE
+        } else {
+            // we adjust the gradle worker id with mod so as to not go over the ephemoral port ranges, but gradle continually
+            // increases this value, so the mod can eventually become zero, thus we shift on both sides by 1
+            final long workerId = Long.valueOf(workerIdStr);
+            assert workerId >= 1 : "Non positive gradle worker id: " + workerIdStr;
+            startAt = Math.floorMod(workerId - 1, 223) + 1;
+        }
         assert startAt >= 0 : "Unexpected test worker Id, resulting port range would be negative";
         return 10300 + (startAt * 100);
     }

test/framework/src/test/java/org/elasticsearch/test/test/ESTestCaseTests.java

@@ -189,7 +189,6 @@ public void testWorkerSystemProperty() {
         assertThat(ESTestCase.TEST_WORKER_VM_ID, not(equals(ESTestCase.DEFAULT_TEST_WORKER_ID)));
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/58279")
     public void testBasePortGradle() {
         assumeTrue("requires running tests with Gradle", System.getProperty("tests.gradle") != null);
         // Gradle worker IDs are 1 based