feat: find available ports for processes (#42)

Author: csviri

core/src/main/java/io/javaoperatorsdk/jenvtest/KubeAPIServer.java

@@ -40,9 +40,9 @@ public void start() {
     binaryManager.initAndDownloadIfRequired();
     certManager.createCertificatesIfNeeded();
     etcdProcess.cleanEtcdData();
-    etcdProcess.startEtcd();
-    kubeApiServerProcess.startApiServer();
-    kubeConfig.updateKubeConfig();
+    var etcdPort = etcdProcess.startEtcd();
+    var apiServerPort = kubeApiServerProcess.startApiServer(etcdPort);
+    kubeConfig.updateKubeConfig(apiServerPort);
     kubeApiServerProcess.waitUntilDefaultNamespaceCreated();
     log.debug("API Server ready to use");
   }

core/src/main/java/io/javaoperatorsdk/jenvtest/KubeConfig.java

@@ -22,9 +22,10 @@ public KubeConfig(CertManager certManager, BinaryManager binaryManager) {
     this.binaryManager = binaryManager;
   }
 
-  public void updateKubeConfig() {
+  public void updateKubeConfig(int apiServerPort) {
     log.debug("Updating kubeconfig");
-    execWithKubectlConfigAndWait("set-cluster", JENVTEST, "--server=https://127.0.0.1:6443",
+    execWithKubectlConfigAndWait("set-cluster", JENVTEST,
+        "--server=https://127.0.0.1:" + apiServerPort,
         "--certificate-authority=" + certManager.getAPIServerCertPath());
     execWithKubectlConfigAndWait("set-credentials", JENVTEST,
         "--client-certificate=" + certManager.getClientCertPath(),

core/src/main/java/io/javaoperatorsdk/jenvtest/Utils.java

@@ -1,6 +1,8 @@
 package io.javaoperatorsdk.jenvtest;
 
+import java.io.IOException;
 import java.io.InputStream;
+import java.net.ServerSocket;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Scanner;
@@ -51,4 +53,11 @@ public static String platformSuffix(OSInfo osInfo) {
     return "-" + osInfo.getOSName() + "-" + osInfo.getOSArch();
   }
 
+  public static int findFreePort() {
+    try (ServerSocket socket = new ServerSocket(0)) {
+      return socket.getLocalPort();
+    } catch (IOException e) {
+    }
+    return -1;
+  }
 }

core/src/main/java/io/javaoperatorsdk/jenvtest/process/EtcdProcess.java

@@ -29,16 +29,17 @@ public EtcdProcess(BinaryManager binaryManager,
     this.processStopHandler = processStopHandler;
   }
 
-  public void startEtcd() {
+  public int startEtcd() {
     var etcdBinary = binaryManager.binaries().getEtcd();
+    var port = Utils.findFreePort();
     try {
       if (!etcdBinary.exists()) {
         throw new JenvtestException(
             "Missing binary for etcd on path: " + etcdBinary.getAbsolutePath());
       }
       etcdProcess = new ProcessBuilder(etcdBinary.getAbsolutePath(),
-          "--listen-client-urls=http://0.0.0.0:2379",
-          "--advertise-client-urls=http://0.0.0.0:2379")
+          "--listen-client-urls=http://0.0.0.0:" + port,
+          "--advertise-client-urls=http://0.0.0.0:" + port)
           .start();
       Utils.redirectProcessOutputToLogger(etcdProcess.getInputStream(), etcdLog);
       Utils.redirectProcessOutputToLogger(etcdProcess.getErrorStream(), etcdLog);
@@ -51,6 +52,7 @@ public void startEtcd() {
         return null;
       });
       log.debug("etcd started");
+      return port;
     } catch (IOException e) {
       throw new JenvtestException(e);
     }

core/src/main/java/io/javaoperatorsdk/jenvtest/process/KubeAPIServerProcess.java

@@ -32,17 +32,18 @@ public KubeAPIServerProcess(CertManager certManager, BinaryManager binaryManager
     this.processStopHandler = processStopHandler;
   }
 
-  public void startApiServer() {
+  public int startApiServer(int etcdPort) {
     var apiServerBinary = binaryManager.binaries().getApiServer();
     try {
       if (!apiServerBinary.exists()) {
         throw new JenvtestException(
             "Missing binary for API Server on path: " + apiServerBinary.getAbsolutePath());
       }
-
+      var port = Utils.findFreePort();
       apiServerProcess = new ProcessBuilder(apiServerBinary.getAbsolutePath(),
           "--cert-dir", config.getJenvtestDir(),
-          "--etcd-servers", "http://0.0.0.0:2379",
+          "--secure-port", "" + port,
+          "--etcd-servers", "http://0.0.0.0:" + etcdPort,
           "--authorization-mode", "RBAC",
           "--service-account-issuer", "https://localhost",
           "--service-account-signing-key-file", certManager.getAPIServerKeyPath(),
@@ -65,6 +66,7 @@ public void startApiServer() {
         return null;
       });
       log.debug("API Server started");
+      return port;
     } catch (IOException e) {
       throw new JenvtestException(e);
     }