Ensure FakeDockerServer is started on a random free port

jamesnetherton · jamesnetherton · commit 221fff63fba1 · 2017-03-06T20:46:56.000Z
diff --git a/src/test/java/com/github/dockerjava/netty/NettyDockerCmdExecFactoryConfigTest.java b/src/test/java/com/github/dockerjava/netty/NettyDockerCmdExecFactoryConfigTest.java
@@ -23,6 +23,8 @@
 import io.netty.handler.codec.http.HttpServerCodec;
 import io.netty.util.CharsetUtil;
 
+import java.io.IOException;
+import java.net.ServerSocket;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -37,16 +39,18 @@ public class NettyDockerCmdExecFactoryConfigTest {
 
     @Test
     public void testNettyDockerCmdExecFactoryConfigWithApiVersion() throws Exception {
+        int dockerPort = getFreePort();
+
         NettyDockerCmdExecFactory factory = new NettyDockerCmdExecFactory();
         Builder configBuilder = DefaultDockerClientConfig.createDefaultConfigBuilder()
-            .withDockerHost("tcp://localhost:2378")
+            .withDockerHost("tcp://localhost:" + dockerPort)
             .withApiVersion("1.23");
 
         DockerClient client = DockerClientBuilder.getInstance(configBuilder)
                 .withDockerCmdExecFactory(factory)
                 .build();
 
-        FakeDockerServer server = new FakeDockerServer(2378);
+        FakeDockerServer server = new FakeDockerServer(dockerPort);
         server.start();
         try {
             client.versionCmd().exec();
@@ -62,14 +66,16 @@ public void testNettyDockerCmdExecFactoryConfigWithApiVersion() throws Exception
 
     @Test
     public void testNettyDockerCmdExecFactoryConfigWithoutApiVersion() throws Exception {
+        int dockerPort = getFreePort();
+
         NettyDockerCmdExecFactory factory = new NettyDockerCmdExecFactory();
-        Builder configBuilder = DefaultDockerClientConfig.createDefaultConfigBuilder().withDockerHost("tcp://localhost:2378");
+        Builder configBuilder = DefaultDockerClientConfig.createDefaultConfigBuilder().withDockerHost("tcp://localhost:" + dockerPort);
 
         DockerClient client = DockerClientBuilder.getInstance(configBuilder)
             .withDockerCmdExecFactory(factory)
             .build();
 
-        FakeDockerServer server = new FakeDockerServer(2378);
+        FakeDockerServer server = new FakeDockerServer(dockerPort);
         server.start();
         try {
             client.versionCmd().exec();
@@ -83,6 +89,13 @@ public void testNettyDockerCmdExecFactoryConfigWithoutApiVersion() throws Except
         }
     }
 
+    private int getFreePort() throws IOException {
+        ServerSocket socket = new ServerSocket(0);
+        int freePort = socket.getLocalPort();
+        socket.close();
+        return freePort;
+    }
+
     private class FakeDockerServer {
         private final int port;
         private final NioEventLoopGroup parent;
