Node.js：如何附加到正在运行的进程并使用控制台调试服务器？

Node.js: How to attach to a running process and to debug the server with a console?

提问by Croplio

I use 'forever' to run my application. I want to attach to the running environment to inspect my application. So what can I do?

我使用“永远”来运行我的应用程序。我想附加到运行环境来检查我的应用程序。那我能做什么？

回答by Bill

From http://nodejs.org/api/debugger.html:

从http://nodejs.org/api/debugger.html：

Advanced Usage

The V8 debugger can be enabled and accessed either by starting Node with the --debug command-line flag or by signaling an existing Node process with SIGUSR1.

高级用法

可以通过使用 --debug 命令行标志启动 Node 或使用 SIGUSR1 向现有 Node 进程发送信号来启用和访问 V8 调试器。

Find the PID of your nodeprocess and then sending SIGUSR1should do the trick:

找到您的node进程的 PID，然后发送SIGUSR1应该可以解决问题：

kill -s SIGUSR1 nodejs-pid

Then run node-inspectorand browse to the URL it indicates. More in this tutorial.

然后运行node-inspector并浏览到它指示的 URL。本教程中的更多内容。

回答by Andrew Mao

Starting from Node 6.3, node has a built-in debugger that can be triggered (even in a production app) by doing:

从Node 6.3开始，node 有一个内置的调试器，可以通过执行以下操作来触发（甚至在生产应用程序中）：

kill -USR1 <node-pid>

The node process will spit out something like this:

节点进程会吐出这样的东西：

Debugger listening on ws://127.0.0.1:9229/f3f6f226-7dbc-4009-95fa-d516ba132fbd
For help see https://nodejs.org/en/docs/inspector

• If you can access the server from a browser, you can use chrome://inspecton http://host.domain:9229.

• If you cannot connect via a browser (e.g. the server is in a firewalled production cluster), you can activate a REPL to inspect over the command line:

  node inspect -p <node-pid>
  

• If you can't access the server from a browser, but you can SSH into that server, then setup SSH port forwarding (ssh -nNTL 9229:localhost:9229 <your_host>) and you'll find your script under chrome://inspectafter a few seconds.

• 如果您可以从浏览器访问服务器，则可以使用chrome://inspecton http://host.domain:9229。

• 如果您无法通过浏览器连接（例如，服务器位于受防火墙保护的生产集群中），您可以激活 REPL 以通过命令行进行检查：

  node inspect -p <node-pid>
  

• 如果您无法从浏览器访问服务器，但可以通过 SSH 连接到该服务器，然后设置 SSH 端口转发 ( ssh -nNTL 9229:localhost:9229 <your_host>)，chrome://inspect几秒钟后您将在下面找到您的脚本。

Prior to this version, node-inspectorwas a separate tool for debugging Node processes. However, as documented on its own page, it is mostly deprecated as the now-bundled debugger is actively maintained and provides more advanced features. For more information on this change, see this thread.

在此版本之前，node-inspector是用于调试 Node 进程的单独工具。然而，正如它自己的页面所记录的那样，它大多已被弃用，因为现在捆绑的调试器得到积极维护并提供更高级的功能。有关此更改的更多信息，请参阅此线程。

回答by danmactough

You can add a REPLto your app. For example, if you add a REPL to listen on localhost port 5001, you start your app as usual and login with telnet: telnet localhost 5001. That will take you to a prompt where you can interact with your app directly.

您可以向您的应用程序添加REPL。例如，如果您添加一个 REPL 来侦听 localhost 端口 5001，则您可以像往常一样启动您的应用程序并使用 telnet: 登录telnet localhost 5001。这将带您进入一个提示，您可以在其中直接与您的应用程序交互。

Alternatively, if you need to your app to "pause" when it reaches a certain state, you need to add "debugger;" lines to areas of your code where you want those breakpoints, then start the app in debugmode.

或者，如果您需要让您的应用在达到某个状态时“暂停”，则需要添加“调试器”；行到您想要这些断点的代码区域，然后在调试模式下启动应用程序。

Hope that helps.

希望有帮助。

回答by zink02

For me, running node version 6.9.10 I had to:

对我来说，运行节点版本 6.9.10 我必须：

kill -USR1 <node-pid>

kill -USR1 <node-pid>

then

然后

node debug -p <node-pid>

node debug -p <node-pid>

the node inspect -p <node-pid>command failed for this version of node.

node inspect -p <node-pid>此版本节点的命令失败。

回答by Qwerty

Windows users

Windows 用户

If you are on Windows that doesn't support POSIX signals, you can use this workaround from anothercmd.

如果您使用的 Windows 不支持 POSIX 信号，则可以从另一个cmd.

node -e "process._debugProcess(PID)"

---

---

为一个 detailed guide详细指南，或在 VSCode 中设置调试，请按照以下简单步骤操作：

1. In VSCode, open launch.jsonconfiguration or create new by clicking on the wheel
   ^{(this is the debug view CtrlShiftD)}

1. 在 VSCode 中，launch.json通过单击滚轮打开配置或创建新配置
   ^{（这是调试视图CtrlShiftD）}

1. The node will listen on port 9229 by default, so add this configuration:

2. 节点默认会监听 9229 端口，所以添加这个配置：

{
  "type": "node",
  "request": "attach",
  "name": "Attach to 9229",
  "port": 9229
},

1. Open Task Manager and locate the PID of your node process
   I could identify my by the "build"folder where the index.jsis.
2. open anothercmdor git-bashand run this command,
   where 21392is the PID of your process.

3. 打开任务管理器并找到您的节点进程的 PID
   我可以通过"build"所在的文件夹识别我的index.js。
4. 打开另一个cmd或git-bash运行此命令，您的进程的 PID
   在哪里21392。

node -e "process._debugProcess(21392)"

1. you should see this
2. Start debugging from VSCode Attach to 9229
   

5. 你应该看到这个
6. 从 VSCode Attach to 9229开始调试
   

Everything should be ready now.

现在一切都应该准备好了。

回答by Miquel

Even it's an old yet answered question, there is an easier way, which is passing parameters to node:

即使这是一个古老但尚未回答的问题，还有一种更简单的方法，即将参数传递给节点：

forever start -c 'node --debug-brk' main.js

If you don't want to wait for debugger to be attached, replace --debug-brkby --debug

如果您不想等待附加调试器，请替换--debug-brk为--debug

回答by DarckBlezzer

To inspect nodejs and debug it, use this command

要检查 nodejs 并调试它，请使用此命令

forever -w -c 'node --inspect=IP:PORT' file.js

forever -w -c 'node --inspect=IP:PORT' file.js

• -cif for a custom command
• use -w to reloadif the file is re-save
• You can pass ip and portfor external inspect
• port custom is 9229

• -c如果是自定义命令
• 如果重新保存文件，请使用-w 重新加载
• 您可以通过 ip 和端口进行外部检查
• 端口自定义为9229