[grid] Enabling detectDrivers original behaviour.

When Selenium Manager was integrated to the Java bindings,
Grid implicitly started using it, saving users time because
they did not need to configure drivers on the Node host
machine anymore.

This seemed ideal but made things harder for advanced users
who were configuring through the different flags for
drivers. For example, a user with a Windows machine, may
not want to use `IEDriverServer`.

This change introduces a new boolean flag `--selenium-manager`
set to `true` by default. When enabled, Selenium Manager will
be used to configure all the possible drivers on the host
machine. When disabled, the Node startup will only look for
drivers that are already present on the host machine.

This is only being implemented in Java because Grid has
that special use case. When using the bindings, users
will continue to pass the driver location or leave it on
the `PATH`to avoid Selenium Manager.

Fixes #11697

Author: diemol

java/src/org/openqa/selenium/WebDriverInfo.java

@@ -66,10 +66,18 @@ public interface WebDriverInfo {
    * that even though the driver classes might be present in Java, it would make no sense to attempt
    * to instantiate the driver itself.
    *
-   * @return Whether or not the prerequisites required for this {@link WebDriver} are present.
+   * @return Whether the prerequisites required for this {@link WebDriver} are present.
    */
   boolean isAvailable();
 
+  /**
+   * Checks whether the browser driver is already present on the host machine. Different from
+   * {@link #isAvailable()} which uses Selenium Manager to obtain the driver when not present.
+   *
+   * @return Whether the browser driver is present on the host machine.
+   */
+  boolean isPresent();
+
   /**
    * Some browsers require all the resources of the current system in order to run (for example,
    * Safari on iOS) and so do not support multiple simultaneous sessions on the same system. Other

java/src/org/openqa/selenium/chrome/ChromeDriverInfo.java

@@ -71,9 +71,14 @@ public boolean isAvailable() {
     }
   }
 
+  @Override
+  public boolean isPresent() {
+    return ChromeDriverService.isPresent();
+  }
+
   @Override
   public Optional<WebDriver> createDriver(Capabilities capabilities)
-      throws SessionNotCreatedException {
+    throws SessionNotCreatedException {
     if (!isAvailable() || !isSupporting(capabilities)) {
       return Optional.empty();
     }

java/src/org/openqa/selenium/chrome/ChromeDriverService.java

@@ -159,27 +159,40 @@ public static ChromeDriverService createDefaultService() {
   @Deprecated
   public static ChromeDriverService createServiceWithConfig(ChromeOptions options) {
     ChromeDriverLogLevel oldLevel = options.getLogLevel();
-    ChromiumDriverLogLevel level = (oldLevel == null) ? null : ChromiumDriverLogLevel.fromString(oldLevel.toString());
+    ChromiumDriverLogLevel level = (oldLevel == null) ? null :
+                                   ChromiumDriverLogLevel.fromString(oldLevel.toString());
     return new Builder()
       .withLogLevel(level)
       .build();
   }
 
+  /**
+   * Checks if the browser driver binary is already present. Grid uses this method to show
+   * the available browsers and drivers, hence its visibility.
+   *
+   * @return Whether the browser driver path was found.
+   */
+  static boolean isPresent() {
+    return findExePath("chromedriver", CHROME_DRIVER_EXE_PROPERTY) != null;
+  }
+
   /**
    * Builder used to configure new {@link ChromeDriverService} instances.
    */
   @AutoService(DriverService.Builder.class)
   public static class Builder extends DriverService.Builder<
-      ChromeDriverService, ChromeDriverService.Builder> {
+    ChromeDriverService, ChromeDriverService.Builder> {
 
     private boolean disableBuildCheck = Boolean.getBoolean(CHROME_DRIVER_DISABLE_BUILD_CHECK);
     private boolean readableTimestamp = Boolean.getBoolean(CHROME_DRIVER_READABLE_TIMESTAMP);
     private boolean appendLog = Boolean.getBoolean(CHROME_DRIVER_APPEND_LOG_PROPERTY);
     private boolean verbose = Boolean.getBoolean(CHROME_DRIVER_VERBOSE_LOG_PROPERTY);
     private boolean silent = Boolean.getBoolean(CHROME_DRIVER_SILENT_OUTPUT_PROPERTY);
     private String allowedListIps = System.getProperty(CHROME_DRIVER_ALLOWED_IPS_PROPERTY,
-      System.getProperty(CHROME_DRIVER_WHITELISTED_IPS_PROPERTY));
-    private ChromiumDriverLogLevel logLevel = ChromiumDriverLogLevel.fromString(System.getProperty(CHROME_DRIVER_LOG_LEVEL_PROPERTY));
+                                                       System.getProperty(
+                                                         CHROME_DRIVER_WHITELISTED_IPS_PROPERTY));
+    private ChromiumDriverLogLevel logLevel = ChromiumDriverLogLevel
+      .fromString(System.getProperty(CHROME_DRIVER_LOG_LEVEL_PROPERTY));
 
     @Override
     public int score(Capabilities capabilities) {

java/src/org/openqa/selenium/edge/EdgeDriverInfo.java

@@ -72,14 +72,19 @@ public boolean isAvailable() {
     }
   }
 
+  @Override
+  public boolean isPresent() {
+    return EdgeDriverService.isPresent();
+  }
+
   @Override
   public int getMaximumSimultaneousSessions() {
     return Runtime.getRuntime().availableProcessors();
   }
 
   @Override
   public Optional<WebDriver> createDriver(Capabilities capabilities)
-      throws SessionNotCreatedException {
+    throws SessionNotCreatedException {
     if (!isAvailable() || !isSupporting(capabilities)) {
       return Optional.empty();
     }

java/src/org/openqa/selenium/edge/EdgeDriverService.java

@@ -122,6 +122,17 @@ public static EdgeDriverService createDefaultService() {
     return new Builder().build();
   }
 
+  /**
+   * Checks if the browser driver binary is already present. Grid uses this method to show
+   * the available browsers and drivers, hence its visibility.
+   *
+   * @return Whether the browser driver path was found.
+   */
+  static boolean isPresent() {
+    return findExePath("msedgedriver", EDGE_DRIVER_EXE_PROPERTY) != null;
+  }
+
+
   /**
    * Builder used to configure new {@link EdgeDriverService} instances.
    */

java/src/org/openqa/selenium/firefox/GeckoDriverInfo.java

@@ -17,9 +17,6 @@
 
 package org.openqa.selenium.firefox;
 
-import static org.openqa.selenium.remote.Browser.FIREFOX;
-import static org.openqa.selenium.remote.CapabilityType.BROWSER_NAME;
-
 import com.google.auto.service.AutoService;
 
 import org.openqa.selenium.Capabilities;
@@ -31,6 +28,9 @@
 
 import java.util.Optional;
 
+import static org.openqa.selenium.remote.Browser.FIREFOX;
+import static org.openqa.selenium.remote.CapabilityType.BROWSER_NAME;
+
 @AutoService(WebDriverInfo.class)
 public class GeckoDriverInfo implements WebDriverInfo {
 
@@ -76,14 +76,19 @@ public boolean isAvailable() {
     }
   }
 
+  @Override
+  public boolean isPresent() {
+    return GeckoDriverService.isPresent();
+  }
+
   @Override
   public int getMaximumSimultaneousSessions() {
     return Runtime.getRuntime().availableProcessors();
   }
 
   @Override
   public Optional<WebDriver> createDriver(Capabilities capabilities)
-      throws SessionNotCreatedException {
+    throws SessionNotCreatedException {
     if (!isAvailable()) {
       return Optional.empty();
     }

java/src/org/openqa/selenium/firefox/GeckoDriverService.java

@@ -101,7 +101,16 @@ public static GeckoDriverService createDefaultService() {
   }
 
   /**
+   * Checks if the browser driver binary is already present. Grid uses this method to show
+   * the available browsers and drivers, hence its visibility.
    *
+   * @return Whether the browser driver path was found.
+   */
+  static boolean isPresent() {
+    return findExePath("geckodriver", GECKO_DRIVER_EXE_PROPERTY) != null;
+  }
+
+  /**
    * @param caps Capabilities instance
    * @return default GeckoDriverService
    */

java/src/org/openqa/selenium/grid/node/config/NodeFlags.java

@@ -43,6 +43,7 @@
 import static org.openqa.selenium.grid.node.config.NodeOptions.DEFAULT_REGISTER_CYCLE;
 import static org.openqa.selenium.grid.node.config.NodeOptions.DEFAULT_REGISTER_PERIOD;
 import static org.openqa.selenium.grid.node.config.NodeOptions.DEFAULT_SESSION_TIMEOUT;
+import static org.openqa.selenium.grid.node.config.NodeOptions.DEFAULT_USE_SELENIUM_MANAGER;
 import static org.openqa.selenium.grid.node.config.NodeOptions.DEFAULT_VNC_ENV_VAR;
 import static org.openqa.selenium.grid.node.config.NodeOptions.NODE_SECTION;
 import static org.openqa.selenium.grid.node.config.NodeOptions.OVERRIDE_MAX_SESSIONS;
@@ -83,6 +84,14 @@ public class NodeFlags implements HasRoles {
   @ConfigValue(section = NODE_SECTION, name = "detect-drivers", example = "true")
   public Boolean autoconfigure = DEFAULT_DETECT_DRIVERS;
 
+  @Parameter(
+    names = {"--selenium-manager"}, arity = 1,
+    description = "When drivers are not available on the current system, fallback to, " +
+                  "Selenium Manager. Drivers will be downloaded the first time a session " +
+                  "request for the given browser is processed.")
+  @ConfigValue(section = NODE_SECTION, name = "selenium-manager", example = "true")
+  public Boolean useSeleniumManager = DEFAULT_USE_SELENIUM_MANAGER;
+
   @Parameter(
     names = {"-I", "--driver-implementation"},
     description = "Drivers that should be checked. If specified, will skip autoconfiguration. " +

java/src/org/openqa/selenium/grid/node/config/NodeOptions.java

@@ -74,6 +74,7 @@ public class NodeOptions {
   public static final boolean DEFAULT_ENABLE_BIDI = true;
   static final String NODE_SECTION = "node";
   static final boolean DEFAULT_DETECT_DRIVERS = true;
+  static final boolean DEFAULT_USE_SELENIUM_MANAGER = true;
   static final boolean OVERRIDE_MAX_SESSIONS = false;
   static final String DEFAULT_VNC_ENV_VAR = "SE_START_XVFB";
   static final int DEFAULT_NO_VNC_PORT = 7900;
@@ -511,11 +512,25 @@ private Map<WebDriverInfo, Collection<SessionFactory>> discoverDrivers(
     // We don't expect duplicates, but they're fine
     List<WebDriverInfo> infos =
       StreamSupport.stream(ServiceLoader.load(WebDriverInfo.class).spliterator(), false)
-        .filter(WebDriverInfo::isAvailable)
+        .filter(WebDriverInfo::isPresent)
         .sorted(Comparator.comparing(info -> info.getDisplayName().toLowerCase()))
         .collect(Collectors.toList());
 
-    LOG.log(Level.INFO, "Discovered {0} driver(s)", infos.size());
+    LOG.log(Level.INFO, "Driver(s) already present on the host: {0}", infos.size());
+
+    if (config.getBool(NODE_SECTION, "selenium-manager").orElse(DEFAULT_USE_SELENIUM_MANAGER)) {
+      List<String> present = infos.stream()
+        .map(WebDriverInfo::getDisplayName)
+        .collect(Collectors.toList());
+      List<WebDriverInfo> driversSM =
+        StreamSupport.stream(ServiceLoader.load(WebDriverInfo.class).spliterator(), false)
+          .filter(WebDriverInfo::isAvailable)
+          .filter(info -> !present.contains(info.getDisplayName()))
+          .sorted(Comparator.comparing(info -> info.getDisplayName().toLowerCase()))
+          .collect(Collectors.toList());
+      LOG.log(Level.INFO, "Driver(s) available through Selenium Manager: {0}", driversSM.size());
+      infos.addAll(driversSM);
+    }
 
     // Same
     List<DriverService.Builder<?, ?>> builders = new ArrayList<>();
@@ -563,14 +578,19 @@ public boolean isSupportingCdp() {
 
       @Override
       public boolean isSupportingBiDi() {
-        return  detectedDriver.isSupportingBiDi();
+        return detectedDriver.isSupportingBiDi();
       }
 
       @Override
       public boolean isAvailable() {
         return detectedDriver.isAvailable();
       }
 
+      @Override
+      public boolean isPresent() {
+        return detectedDriver.isPresent();
+      }
+
       @Override
       public int getMaximumSimultaneousSessions() {
         return detectedDriver.getMaximumSimultaneousSessions();
@@ -625,9 +645,10 @@ private void report(Map.Entry<WebDriverInfo, Collection<SessionFactory>> entry)
     }
 
     LOG.info(String.format(
-      "Adding %s for %s %d times",
+      "Adding %s for %s %d times (%s)",
       entry.getKey().getDisplayName(),
       caps.toString().replaceAll("\\s+", " "),
-      entry.getValue().size()));
+      entry.getValue().size(),
+      entry.getKey().isPresent() ? "Host" : "SM"));
   }
 }

java/src/org/openqa/selenium/ie/InternetExplorerDriverInfo.java

@@ -74,14 +74,19 @@ public boolean isAvailable() {
     }
   }
 
+  @Override
+  public boolean isPresent() {
+    return InternetExplorerDriverService.isPresent();
+  }
+
   @Override
   public int getMaximumSimultaneousSessions() {
     return 1;
   }
 
   @Override
   public Optional<WebDriver> createDriver(Capabilities capabilities)
-      throws SessionNotCreatedException {
+    throws SessionNotCreatedException {
     if (!isAvailable()) {
       return Optional.empty();
     }