第二次发布时,Selenium Marionette驱动程序UnreachableBrowserException

Question

我正在玩Selenium Marionette WebDriver.在我的应用程序中,我想顺序打开多个Marionette驱动程序.基本上是这样的:

MarionetteDriver driver = new MarionetteDriver();
// do some stuff
driver.quit();

// a while later

driver = new MarionetteDriver();
// do some stuff
driver.quit();

现在我面临的问题是,只有第一个Marionette实例可以成功启动,并且对于每个后来的尝试,我都会遇到以下异常.问题每次都会发生,并且使用的端口总是在变化,因此显然没有端口冲突.

Exception in thread "main" org.openqa.selenium.remote.UnreachableBrowserException: Could not start a new session. Possible causes are invalid address of the remote server or browser start-up failure.
Build info: version: '2.48.2', revision: '41bccdd10cf2c0560f637404c2d96164b67d9d67', time: '2015-10-09 13:08:06'
System info: host: 'qqilihq.local', ip: '192.168.1.2', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.11.2', java.version: '1.7.0_71'
Driver info: driver.version: MarionetteDriver
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:641)
    at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:247)
    at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:232)
    at org.openqa.selenium.firefox.MarionetteDriver.run(MarionetteDriver.java:84)
    at org.openqa.selenium.firefox.MarionetteDriver.<init>(MarionetteDriver.java:73)
    at org.openqa.selenium.firefox.MarionetteDriver.<init>(MarionetteDriver.java:45)
    at MyMainClass.main(MyMainClass.java:131)
Caused by: org.openqa.selenium.WebDriverException: org.apache.http.conn.HttpHostConnectException: Connect to localhost:41886 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused
Build info: version: '2.48.2', revision: '41bccdd10cf2c0560f637404c2d96164b67d9d67', time: '2015-10-09 13:08:06'
System info: host: 'qqilihq.local', ip: '192.168.1.2', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.11.2', java.version: '1.7.0_71'
Driver info: driver.version: MarionetteDriver
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:91)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:620)
    ... 6 more
Caused by: org.apache.http.conn.HttpHostConnectException: Connect to localhost:41886 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused
    at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:151)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:353)
    at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:380)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:71)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
    at org.openqa.selenium.remote.internal.ApacheHttpClient.fallBackExecute(ApacheHttpClient.java:143)
    at org.openqa.selenium.remote.internal.ApacheHttpClient.execute(ApacheHttpClient.java:89)
    at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:142)
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:82)
    ... 7 more
Caused by: java.net.ConnectException: Connection refused
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at org.apache.http.conn.socket.PlainConnectionSocketFactory.connectSocket(PlainConnectionSocketFactory.java:74)
    at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.    java:134)
    ... 20 more

任何指针赞赏!

Answer 1

在深入挖掘之后,我得出了以下结论,最终解决了我的问题:

1. 木偶和 wires使用两个端口(见wires --help); a marionette-port和a webdriver-port:

   Usage:
       ./wires [OPTIONS]
   
   WebDriver to marionette proxy.
   
   optional arguments:
     -h,--help             show this help message and exit
     -b,--binary BINARY    Path to the Firefox binary
     --webdriver-host WEBDRIVER_HOST
                           Host to run webdriver server on
     --webdriver-port WEBDRIVER_PORT
                           Port to run webdriver on
     --marionette-port MARIONETTE_PORT
                           Port to run marionette on
     --connect-existing    Connect to an existing firefox process
   

   当MarionetteDrivers同时运行多个端口时,两个端口显然必须与已经运行的实例不同.但是,使用默认构造函数时new MarionetteDriver(),marionette-port保持不变(并且不基于某个空闲端口确定).我们使用了一些解决方法(见下文)GeckoDriverService.Builder来始终选择两个随机选择的可用端口.

2. 当前(版本2.48.2)GeckoDriverService有一个空的实现waitUntilAvailable()(如果WebDriver准备就绪,应该检查).偶尔,这导致UnreachableBrowserException上面发布.

为了规避这些问题,我们在最后做了类似的事情:

// determine free ports for Marionette and WebDriver
final int marionettePort = PortProber.findFreePort();
final int webDriverPort = PortProber.findFreePort();
// override, as GeckoDriverService provides no direct way to set the Marionette port
GeckoDriverService.Builder builder = new GeckoDriverService.Builder() {
    @Override
    protected ImmutableList<String> createArgs() {
        Builder<String> argsBuilder = ImmutableList.builder();
        argsBuilder.addAll(super.createArgs());
        argsBuilder.add(String.format("--marionette-port=%d", marionettePort));
        return argsBuilder.build();
    }
};
builder.usingPort(webDriverPort);
builder.usingDriverExecutable(pathToDriver);
GeckoDriverService driverService = builder.build();
try {
    driverService.start();
} catch (IOException e) {
    throw new IllegalStateException("Could not start the GeckoDriverService", e);
}
try {
    // keep checking the WebDriver port via Socket until it's available;
    // as far as I could tell, there is nothing more "high level", e.g. REST API
    waitUntilReady(webDriverPort, TimeUnit.SECONDS.toMillis(30));
} catch (InterruptedException e) {
    // ignore
}
return new MarionetteDriver(driverService, capabilities);