Randomize wiremock port

Avoid unwanted interactions between tests by randomizing the wiremock
server port when possible.

Change-Id: I17cb7280755d73b92b9bdde4240bf6c517c77f2e
diff --git a/src/test/java/com/ericsson/gerrit/plugins/evictcache/Constants.java b/src/test/java/com/ericsson/gerrit/plugins/evictcache/Constants.java
index f7ba16c..ce6d933 100644
--- a/src/test/java/com/ericsson/gerrit/plugins/evictcache/Constants.java
+++ b/src/test/java/com/ericsson/gerrit/plugins/evictcache/Constants.java
@@ -19,7 +19,6 @@
   private Constants() {
   }
 
-  static final String URL = "http://localhost:18888";
   static final String ENDPOINT_BASE = "/plugins/evict-cache/gerrit/evict/";
   static final String PROJECT_LIST = "project_list";
   static final String ACCOUNTS = "accounts";
@@ -27,6 +26,4 @@
   static final String GROUPS_BYINCLUDE = "groups_byinclude";
   static final String GROUPS_MEMBERS = "groups_members";
   static final String DEFAULT = "projects";
-
-  static final int PORT = 18888;
 }
diff --git a/src/test/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheIT.java b/src/test/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheIT.java
index 2e71d2f..a6d61cb 100644
--- a/src/test/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheIT.java
+++ b/src/test/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheIT.java
@@ -46,12 +46,14 @@
     httpModule = "com.ericsson.gerrit.plugins.evictcache.HttpModule"
 )
 public class EvictCacheIT extends LightweightPluginDaemonTest {
+  private static final int PORT = 18888;
+  private static final String URL = "http://localhost:" + PORT;
 
   @Rule
-  public WireMockRule wireMockRule = new WireMockRule(Constants.PORT);
+  public WireMockRule wireMockRule = new WireMockRule(PORT);
 
   @Test
-  @GerritConfig(name = "plugin.evict-cache.url", value = Constants.URL)
+  @GerritConfig(name = "plugin.evict-cache.url", value = URL)
   @GerritConfig(name = "plugin.evict-cache.user", value = "admin")
   public void flushAndSendPost() throws Exception {
     final String flushRequest =
diff --git a/src/test/java/com/ericsson/gerrit/plugins/evictcache/HttpSessionTest.java b/src/test/java/com/ericsson/gerrit/plugins/evictcache/HttpSessionTest.java
index f45e52d..cb03159 100644
--- a/src/test/java/com/ericsson/gerrit/plugins/evictcache/HttpSessionTest.java
+++ b/src/test/java/com/ericsson/gerrit/plugins/evictcache/HttpSessionTest.java
@@ -54,12 +54,13 @@
   private HttpSession httpSession;
 
   @Rule
-  public WireMockRule wireMockRule = new WireMockRule(Constants.PORT);
+  public WireMockRule wireMockRule = new WireMockRule(0);
 
   @Before
   public void setUp() throws Exception {
+    String url = "http://localhost:" + wireMockRule.port();
     Configuration cfg = mock(Configuration.class);
-    when(cfg.getUrl()).thenReturn(Constants.URL);
+    when(cfg.getUrl()).thenReturn(url);
     when(cfg.getUser()).thenReturn("user");
     when(cfg.getPassword()).thenReturn("pass");
     when(cfg.getMaxTries()).thenReturn(MAX_TRIES);
@@ -68,7 +69,7 @@
     when(cfg.getRetryInterval()).thenReturn(RETRY_INTERVAL);
 
     httpSession =
-        new HttpSession(new HttpClientProvider(cfg).get(), Constants.URL);
+        new HttpSession(new HttpClientProvider(cfg).get(), url);
   }
 
   @Test