测试立即失败，出现未知错误：通过 systemd 运行 Selenium 网格时，DevToolsActivePort 文件不存在答案

【问题标题】：Tests fail immediately with unknown error: DevToolsActivePort file doesn't exist when running Selenium grid through systemd测试立即失败，出现未知错误：通过 systemd 运行 Selenium 网格时，DevToolsActivePort 文件不存在
【发布时间】：2020-01-31 00:00:59
【问题描述】：

我一直在尝试将 Selenium 网格服务的启动方式从 .rclocal 中的 shell 脚本更改为 systemd 服务，但它不起作用。脚本是这样的：

#!/bin/bash
java -jar /opt/selenium-server-standalone.jar -role hub -hubConfig hubconfig.json
xvfb-run --server-args="-screen 0 2048x1536x24" java -jar /opt/selenium-server-standalone.jar -role 
node -nodeConfig nodeconfig.json

我创建了如下两个不同的服务：

（Stackoverflow 不允许我放置服务的内容，因为它说它的格式不正确）

服务正在正确启动：

selenium-hub

● selenium-hub.service - Selenium service
   Loaded: loaded (/etc/systemd/system/selenium-hub.service; disabled; vendor preset: disabled)
   Active: active (running) since Tue 2019-10-01 15:53:10 UTC; 2min 41s ago
 Main PID: 23803 (java)
   CGroup: /system.slice/selenium-hub.service
           └─23803 /bin/java -jar /opt/selenium-server-standalone.jar -role hub -hubConfig /home/selenium/hubconfig.json

Oct 01 15:53:12 vm java[23803]: 15:53:12.163 INFO - Selenium build info: version: '3.9.1', revision: '63f7b50'
Oct 01 15:53:12 vm java[23803]: 15:53:12.164 INFO - Launching Selenium Grid hub on port 4444
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.384:INFO::main: Logging initialized @2790ms to org.seleniumhq.jetty9.util.log.StdErrLog
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.492:INFO:osjs.Server:main: jetty-9.4.7.v20170914, build timestamp: 2017-11-21T21:27:37Z, git hash: 82b8fb23f757335bb3329d540ce37a2a2615f0a8
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.524:INFO:osjs.session:main: DefaultSessionIdManager workerName=node0
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.524:INFO:osjs.session:main: No SessionScavenger set, using defaults
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.529:INFO:osjs.session:main: Scavenging every 660000ms
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.538:INFO:osjsh.ContextHandler:main: Started o.s.j.s.ServletContextHandler@60704c{/,null,AVAILABLE}
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.562:INFO:osjs.AbstractConnector:main: Started ServerConnector@1fe20588{HTTP/1.1,[http/1.1]}{0.0.0.0:4444}
Oct 01 15:53:13 vm java[23803]: 2019-10-01 15:53:13.562:INFO:osjs.Server:main: Started @2968ms
Oct 01 15:53:13 vm java[23803]: 15:53:13.562 INFO - Selenium Grid hub is up and running
Oct 01 15:53:13 vm java[23803]: 15:53:13.562 INFO - Nodes should register to http://1.2.3.4:4444/grid/register/
Oct 01 15:53:13 vm java[23803]: 15:53:13.562 INFO - Clients should connect to http://1.2.3.4:4444/wd/hub
Oct 01 15:53:14 vm java[23803]: 15:53:14.797 INFO - Registered a node http://1.2.3.4:5555

selenium-node:

● selenium-node.service - Selenium nodes
   Loaded: loaded (/etc/systemd/system/selenium-node.service; disabled; vendor preset: disabled)
   Active: active (running) since Tue 2019-10-01 15:53:10 UTC; 6min ago
 Main PID: 23813 (xvfb-run)
   CGroup: /system.slice/selenium-node.service
           ├─23813 /bin/sh /bin/xvfb-run --server-args="-screen 0 2048x1536x24" java -jar /opt/selenium-server-standalone.jar -role node -nodeConfig /home/selenium/nodeconfig.json
           ├─23856 java -jar /opt/selenium-server-standalone.jar -role node -nodeConfig /home/selenium/nodeconfig.json
           ├─24326 /usr/local/bin/chromedriver --port=1713
           ├─24327 /usr/local/bin/chromedriver --port=26741
           ├─24328 /usr/local/bin/chromedriver --port=20065
           ├─24329 /usr/local/bin/chromedriver --port=6459
           ├─24331 /usr/local/bin/chromedriver --port=15872
           ├─24332 /usr/local/bin/chromedriver --port=29475
           ├─24333 /usr/local/bin/chromedriver --port=30216
           ├─24334 /usr/local/bin/chromedriver --port=6955
           ├─24558 /usr/local/bin/chromedriver --port=2425
           ├─24559 /usr/local/bin/chromedriver --port=19304
           ├─24560 /usr/local/bin/chromedriver --port=12150
           ├─24561 /usr/local/bin/chromedriver --port=26147
           ├─24562 /usr/local/bin/chromedriver --port=16545
           ├─24570 /usr/local/bin/chromedriver --port=12780
           ├─24602 /usr/local/bin/chromedriver --port=10959
           ├─24603 /usr/local/bin/chromedriver --port=8970
           ├─24753 /usr/local/bin/chromedriver --port=13438
           ├─24754 /usr/local/bin/chromedriver --port=15725
           └─24772 /usr/local/bin/chromedriver --port=28829

Oct 01 15:55:19 vm xvfb-run[23813]: Starting ChromeDriver 77.0.3865.40 (f484704e052e0b556f8030b65b953dce96503217-refs/branch-heads/3865@{#442}) on port 15725
Oct 01 15:55:19 vm xvfb-run[23813]: Only local connections are allowed.
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.112 INFO - /session: Executing POST on /session (handler: BeginSession)
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.113 INFO - Capabilities are: Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.114 INFO - Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm-usage, window-siz
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.115 INFO - Found handler: org.openqa.selenium.remote.server.commandhandler.BeginSession@53702c02
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.115 INFO - Found handler: org.openqa.selenium.remote.server.commandhandler.BeginSession@4ae12041
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.116 INFO - /session: Executing POST on /session (handler: BeginSession)
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.117 INFO - Capabilities are: Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.118 INFO - Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm-usage, window-siz
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.118 INFO - /session: Executing POST on /session (handler: BeginSession)
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.120 INFO - Capabilities are: Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.120 INFO - Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm-usage, window-siz
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.121 INFO - /session: Executing POST on /session (handler: BeginSession)
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.123 INFO - Capabilities are: Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.123 INFO - Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm-usage, window-siz
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.124 INFO - /session: Executing POST on /session (handler: BeginSession)
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.139 INFO - Capabilities are: Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm
Oct 01 15:55:19 vm xvfb-run[23813]: 15:55:19.139 INFO - Capabilities {browserName: chrome, goog:chromeOptions: {args: [enable-automation, disable-infobars, disable-notifications, no-sandbox, --disable-dev-shm-usage, window-siz
Oct 01 15:55:19 vm xvfb-run[23813]: Starting ChromeDriver 77.0.3865.40 (f484704e052e0b556f8030b65b953dce96503217-refs/branch-heads/3865@{#442}) on port 26147
Oct 01 15:55:19 vm xvfb-run[23813]: Only local connections are allowed.
Oct 01 15:55:19 vm xvfb-run[23813]: Please protect ports used by ChromeDriver and related test frameworks to prevent access by malicious code.

但是所有测试都失败并出现相同的错误：

OpenQA.Selenium.WebDriverException: unknown error: Chrome failed to start: exited abnormally
(unknown error: DevToolsActivePort file doesn't exist)
(The process started from chrome location /usr/bin/google-chrome is no longer running, so ChromeDriver is assuming that Chrome has crashed.)
Build info: version: '3.9.1', revision: '63f7b50', time: '2018-02-07T22:42:28.403Z'

DevToolsActivePort 的问题源于 /dev/shm 太小，有时会导致浏览器崩溃（https://stackoverflow.com/a/50642913/5364231、https://bugs.chromium.org/p/chromium/issues/detail?id=736452#c64），所以我已经在功能中添加了--disable-dev-shm-usage。

我认为问题在于服务selenium-hub 无法与selenium-node 通信。非常感谢任何帮助。

【问题讨论】：

标签： selenium selenium-webdriver centos systemd selenium-grid

【解决方案1】：

拇指规则

Chrome 在启动期间崩溃的一个常见原因是在 Linux 上以 root 用户 (administrator) 运行 Chrome。虽然可以通过在创建 WebDriver 会话时传递 --no-sandbox 标志来解决此问题，但不支持并且强烈建议不要使用此类配置。您需要将环境配置为以普通用户身份运行 Chrome。

此错误消息...

OpenQA.Selenium.WebDriverException: unknown error: Chrome failed to start: exited abnormally
(unknown error: DevToolsActivePort file doesn't exist)
(The process started from chrome location /usr/bin/google-chrome is no longer running, so ChromeDriver is assuming that Chrome has crashed.)
Build info: version: '3.9.1', revision: '63f7b50', time: '2018-02-07T22:42:28.403Z'

...暗示 ChromeDriver 无法启动/生成新的 WebBrowser 即 Chrome 浏览器 会话。

您的主要问题是您使用的二进制文件版本之间的不兼容性，如下所示：

您使用的是最新的 chromedriver=77.0
大概您正在使用 chrome= 77.0。
您的 Selenium Client 版本是 2018-02-07T22:42:28.403Z 的 3.9.1，几乎是 1.5 岁。

因此 Selenium Client v3.9.1 、ChromeDriver v77.0 和 Chrome 浏览器 v77.0 之间存在明显的不匹配性 /p>

解决方案

确保：

JDK 升级到当前级别JDK 8u221。

Selenium 升级到当前级别 Version 3.141.59。

ChromeDriver 已更新到当前的ChromeDriver v77.0 级别。

Chrome 已更新至当前 Chrome 版本 77.0 级别。（根据ChromeDriver v77.0 release notes）

清理你的项目工作区通过你的IDE和重建你的项目只需要依赖。

如果您的基本 Web 客户端 版本太旧，请卸载它并安装最新的 GA 和发布版本的 Web 客户端。

进行系统重启。

以非root用户身份执行@Test。

参考

您可以在以下位置找到一些详细的讨论：

org.openqa.selenium.WebDriverException: unknown error: DevToolsActivePort file doesn't exist while trying to initiate Chrome Browser

unknown error: DevToolsActivePort file doesn't exist error while executing Selenium UI test cases on ubuntu

结尾

这是Sandbox故事的链接。

【讨论】：