Refactor jetty client test to use nginx in docker as http backend (#276)

Author: mhalbritter

tests/src/org.eclipse.jetty/jetty-client/11.0.12/.gitignore

@@ -2,3 +2,5 @@ gradlew.bat
 gradlew
 gradle/
 build/
+nginx-stderr.txt
+nginx-stdout.txt

tests/src/org.eclipse.jetty/jetty-client/11.0.12/required-docker-images.txt

@@ -0,0 +1 @@
+nginx:1-alpine-slim

tests/src/org.eclipse.jetty/jetty-client/11.0.12/src/test/java/org_eclipse_jetty/jetty_client/JettyClientTest.java

@@ -8,23 +8,92 @@
 
 import org.eclipse.jetty.client.HttpClient;
 import org.eclipse.jetty.client.api.ContentResponse;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
+import java.io.File;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.net.SocketTimeoutException;
+
 import static org.assertj.core.api.Assertions.assertThat;
 
 class JettyClientTest {
 
-    // This test communicates with external service so it should be disabled until it is refactored. See related issue: https://github.com/oracle/graalvm-reachability-metadata/issues/259
-    private static final boolean DISABLE_TEST = true;
+    private static final int HOST_PORT = 12345;
+
+    private static Process process;
+
+    @BeforeAll
+    static void beforeAll() throws IOException {
+        System.out.println("Starting nginx ...");
+        process = new ProcessBuilder(
+                "docker", "run", "--rm", "-p", HOST_PORT + ":80",
+                "nginx:1-alpine-slim")
+                .redirectOutput(new File("nginx-stdout.txt"))
+                .redirectError(new File("nginx-stderr.txt"))
+                .start();
+
+        // Wait until connection can be established
+        waitUntilContainerStarted(60);
+
+        System.out.println("nginx started");
+    }
+
+    private static void waitUntilContainerStarted(int startupTimeoutSeconds) {
+        System.out.println("Waiting for nginx container to become available");
+
+        Exception lastConnectionException = null;
+
+        long end = System.currentTimeMillis() + startupTimeoutSeconds * 1000L;
+        while (System.currentTimeMillis() < end) {
+            try {
+                Thread.sleep(100L);
+            } catch (InterruptedException e) {
+                // continue
+            }
+            try (Socket socket = new Socket()) {
+                socket.setSoTimeout(100);
+                socket.connect(new InetSocketAddress("localhost", HOST_PORT), 100);
+                if (!check(socket)) {
+                    continue;
+                }
+                return;
+            } catch (Exception e) {
+                lastConnectionException = e;
+            }
+        }
+        throw new IllegalStateException("nginx container cannot be accessed on localhost:" + HOST_PORT, lastConnectionException);
+    }
+
+    private static boolean check(Socket socket) throws IOException {
+        try {
+            // -1 indicates the socket has been closed immediately
+            // Other responses or a timeout are considered as success
+            if (socket.getInputStream().read() == -1) {
+                return false;
+            }
+        } catch (SocketTimeoutException ex) {
+        }
+        return true;
+    }
+
+    @AfterAll
+    static void tearDown() {
+        if (process != null && process.isAlive()) {
+            System.out.println("Shutting down nginx");
+            process.destroy();
+        }
+    }
+
     @Test
     void test() throws Exception {
-        if (DISABLE_TEST) {
-            return;
-        }
         HttpClient client = new HttpClient();
         client.start();
         try {
-            ContentResponse response = client.GET("https://httpbin.org/get");
+            ContentResponse response = client.GET("http://localhost:%d/".formatted(HOST_PORT));
             assertThat(response.getStatus()).isEqualTo(200);
         } finally {
             client.stop();