搭建apprtc遇到的一个问题：closurecompiler@1.6.1无法npm install

搭建WebRTC服务器，有一步就是：进到源码apprtc目录下，使用npm install命令将package.json里的依赖包都给装上，这些依赖包将被安装到当前目录下的node_modules目录下，需要安装的依赖包很多，都是从http://registry.npmjs.org下载的，遗憾并不顺利，有个closurecompiler死活装不上，报错如下：

root@cat:~/apprtc# npm install

> closurecompiler@1.6.1 install /root/apprtc/node_modules/closurecompiler
> npm run-script configure

sh: 1: npm: Permission denied
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.0.7 (node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.0.7: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.9 (node_modules/nunjucks/node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.9: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})

npm ERR! code ELIFECYCLE
npm ERR! syscall spawn
npm ERR! file sh
npm ERR! errno ENOENT
npm ERR! closurecompiler@1.6.1 install: `npm run-script configure`
npm ERR! spawn ENOENT
npm ERR!
npm ERR! Failed at the closurecompiler@1.6.1 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2020-02-07T05_57_38_544Z-debug.log

看到报的这一堆错误，百度后，有的说是权限问题，加上sudo就能解决，还有的说要换npm源https://registry.npm.taobao.org，结果都不奏效。最后找到这个closurecompiler项目的github网址：https://github.com/dcodeIO/ClosureCompiler.js，其git地址为：https://github.com/dcodeIO/ClosureCompiler.js.git，于是直接git clone到node_modules目录下，里面有了一个closurecompiler目录，以为大功告成了，后来发现这个closurecompiler的子目录compiler里面少了一个jar包：closure-compiler-v20200112.jar。没有它，apprtc.debug.js这个文件就编译不出来。实际上这个jar包可以从这里下载：https://dl.google.com/closure-compiler/compiler-latest.tar.gz。本人后来发现在windows下搭建node环境，使用npm install -g closurecompiler是可以成功安装closurecompiler到全局的node_modules下的，整个过程如下：

$ npm install -g closurecompiler
E:\1234\RTC\node-v8.17.0-win-x64\ccjs -> E:\1234\RTC\node-v8.17.0-win-x64\node_modules\closurecompiler\bin\ccjs

> closurecompiler@1.6.1 install E:\1234\RTC\node-v8.17.0-win-x64\node_modules\closurecompiler
> npm run-script configure


> closurecompiler@1.6.1 configure E:\1234\RTC\node-v8.17.0-win-x64\node_modules\closurecompiler
> node scripts/configure.js

Configuring ClosureCompiler.js 1.6.1 ...

  Downloading https://dl.google.com/closure-compiler/compiler-latest.tar.gz ...
  | 0 / 7 mb
  | 1 / 7 mb
  | 2 / 7 mb
  | 3 / 7 mb
  | 4 / 7 mb
  | 5 / 7 mb
  | 6 / 7 mb
  | 7 / 7 mb
  ✔ Download complete: E:\1234\RTC\node-v8.17.0-win-x64\node_modules\closurecompiler\compiler\compiler.tar.gz (7 mb)

  Unpacking E:\1234\RTC\node-v8.17.0-win-x64\node_modules\closurecompiler\compiler\compiler.tar.gz ...
  | closure-compiler-v20200112.jar
  | COPYING
  | README.md
  ✔ Unpack complete.

  Configuring JRE ...
  ✔ Global Java is available, perfect!

  ✔ ClosureCompiler.js has successfully been configured!

+ closurecompiler@1.6.1
added 25 packages from 6 contributors in 40.414s

上面的E:\1234\RTC\node-v8.17.0-win-x64\是我在windows下的node安装路径。然后我就把E:\1234\RTC\node-v8.17.0-win-x64\node_modules\closurecompiler这个目录打个压缩包，弄到apprtc目录下面的node_modules下解压后，grunt build，没有出现错误，这次终于成功了。编译过程如下：

Running "shell:buildAppEnginePackage" (shell) task

Running "shell:genJsEnums" (shell) task
src >>> src/web_app/js

Running "closurecompiler:debug" (closurecompiler) task

Compiling node_modules/webrtc-adapter/out/adapter.js,src/web_app/js/analytics.js,src/web_app/js/enums.js,src/web_app/js/appcontroller.js,src/web_app/js/call.js,src/web_app/js/constants.js,src/web_app/js/infobox.js,src/web_app/js/peerconnectionclient.js,src/web_app/js/remotewebsocket.js,src/web_app/js/roomselection.js,src/web_app/js/sdputils.js,src/web_app/js/signalingchannel.js,src/web_app/js/stats.js,src/web_app/js/storage.js,src/web_app/js/util.js,src/web_app/js/windowport.js -> out/app_engine/js/apprtc.debug.js
>> Complete: 276879

Running "grunt-chrome-build:apprtc" (grunt-chrome-build) task
Chrome packaged app build.
Deleting buildDir: out/chrome_app
Creating empty buildDir: out/chrome_app
Copying resources to buildDir: out/chrome_app
object
out/chrome_app/manifest.json
src/web_app/chrome_app/manifest.json-->out/chrome_app/manifest.json
object
out/chrome_app/js/apprtc.debug.js
out/app_engine/js/apprtc.debug.js-->out/chrome_app/js/apprtc.debug.js
object
out/chrome_app/js/loopback.js
out/app_engine/js/loopback.js-->out/chrome_app/js/loopback.js
object
out/chrome_app/third_party/pako/pako.min.js
out/app_engine/third_party/pako/pako.min.js-->out/chrome_app/third_party/pako/pako.min.js
object
out/chrome_app/css/main.css
out/app_engine/css/main.css-->out/chrome_app/css/main.css
object
out/chrome_app/images/apprtc-128.png
out/app_engine/images/apprtc-128.png-->out/chrome_app/images/apprtc-128.png
object
out/chrome_app/images/apprtc-16.png
out/app_engine/images/apprtc-16.png-->out/chrome_app/images/apprtc-16.png
object
out/chrome_app/images/apprtc-22.png
out/app_engine/images/apprtc-22.png-->out/chrome_app/images/apprtc-22.png
object
out/chrome_app/images/apprtc-32.png
out/app_engine/images/apprtc-32.png-->out/chrome_app/images/apprtc-32.png
object
out/chrome_app/images/apprtc-48.png
out/app_engine/images/apprtc-48.png-->out/chrome_app/images/apprtc-48.png
object
out/chrome_app/js/background.js
src/web_app/js/background.js-->out/chrome_app/js/background.js
object
out/chrome_app/js/appwindow.js
src/web_app/js/appwindow.js-->out/chrome_app/js/appwindow.js

Running "grunt-chrome-build-transform" task
Transforming files using jinja.

Running "jinja:chrome-build" (jinja) task
Using context web_app/html/index_template
File "out/chrome_app/appwindow.html" created.

Running "grunt-chrome-build-compress" task
Creating zip file:out/chrome_app/apprtc.zip

Running "compress:chrome-build" (compress) task
>> Compressed 18 files.

Running "grunt-chrome-build-package" task
Skipping creation of Chrome package.

Done.

我把这个closurecompiler打包后放在这里：https://sifangyun.cn/download/closurecompiler.tar.gz，以方便遇到同样坑坑的小伙伴下载。