Bundle Theia backend

[msujew]

Feature Description:

Even though node.js is able to run the Theia backend as it is (fragmented across node_modules) perfectly fine, it would be worth looking into bundling the backend. This has a few benefits for devs/users:

• Faster Startup. Less file system accesses and minification lead to shorter cold startup times.
• Smaller application sizes. This is particularly relevant for the Electron build which users have to download and install to disk.
• Simplifies moving the application from one directory/system to another. Relevant for Support SSH Remote Development #12390

[kittaakos]

Related: #4541

[sdirix]

For anyone interested: There is a WIP PR by @paul-marechal for Theia Blueprint which includes bundling the backend with Webpack.

[msujew]

Just a few remarks on the implemented changes from #12412:

• Server cold startup time down from ~4 seconds to ~1.5 seconds.
• Full application size down from ~300mb to ~130mb.

[jfaltermeier]

Hi, I was trying to integrate these changes in Theia Blueprint and struggled.
So I thought I will give it a try with the Theia Electron Example first.

So basically what I did is to replace
"bundle": "yarn rebuild && theia build --mode development" with "bundle": "yarn rebuild && theia build --mode production" and updated start like this "start": "node ./lib/backend/electron-main.js", in theia/examples/electron/package.json

On ubuntu running yarn electron build fails with

ERROR in ../../node_modules/@vscode/proxy-agent/out/index.js 380:70-105
Module not found: Error: Can't resolve '@vscode/windows-ca-certs/build/Release/crypt32.node' in '/home/johannes/Git/theia/node_modules/@vscode/proxy-agent/out'
resolve '@vscode/windows-ca-certs/build/Release/crypt32.node' in '/home/johannes/Git/theia/node_modules/@vscode/proxy-agent/out'
  Parsed request is a module
  using description file: /home/johannes/Git/theia/node_modules/@vscode/proxy-agent/package.json (relative path: ./out)
    resolve as module
      /home/johannes/Git/theia/node_modules/@vscode/proxy-agent/out/node_modules doesn't exist or is not a directory
      looking for modules in /home/johannes/Git/theia/node_modules/@vscode/proxy-agent/node_modules
        /home/johannes/Git/theia/node_modules/@vscode/proxy-agent/node_modules/@vscode/windows-ca-certs doesn't exist
      /home/johannes/Git/theia/node_modules/@vscode/node_modules doesn't exist or is not a directory
      /home/johannes/Git/theia/node_modules/node_modules doesn't exist or is not a directory
      looking for modules in /home/johannes/Git/theia/node_modules
        /home/johannes/Git/theia/node_modules/@vscode/windows-ca-certs doesn't exist
      looking for modules in /home/johannes/Git/node_modules
        /home/johannes/Git/node_modules/@vscode/windows-ca-certs doesn't exist
      /home/johannes/node_modules doesn't exist or is not a directory
      /home/node_modules doesn't exist or is not a directory
      /node_modules doesn't exist or is not a directory
 @ ../../packages/plugin-ext/lib/hosted/node/plugin-host-proxy.js 22:22-52
 @ ../../packages/plugin-ext/lib/hosted/node/plugin-host-rpc.js 35:28-58
 @ ../../packages/plugin-ext/lib/hosted/node/plugin-host.js 21:26-54

webpack 5.76.2 compiled with 1 error and 136 warnings in 64656 ms

Error: webpack exited with an unexpected code: 1.
    at ChildProcess.<anonymous> (/home/johannes/Git/theia/dev-packages/application-manager/lib/application-process.js:66:28)
    at ChildProcess.emit (node:events:520:28)
    at maybeClose (node:internal/child_process:1092:16)
    at Process.ChildProcess._handle.onexit (node:internal/child_process:302:5)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

On windows running yarn electron build works. When running yarn electron start (without deleting any node_modules yet) I get this error:

TypeError: Cannot set properties of undefined (setting 'allowRendererProcessReuse')
    at Object.2951 (C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:3177)
    at o (C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:42522)
    at C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:42650
    at Function.o.O (C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:42901)
    at o.x (C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:42671)
    at Function.o.x (C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:43866)
    at C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:43873
    at Object.<anonymous> (C:\Users\user\git\theia\examples\electron\lib\backend\electron-main.js:1:43878)
    at Module._compile (node:internal/modules/cjs/loader:1196:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1250:10)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Am I doing something wrong or is there an issue with the current release?

[msujew]

@jfaltermeier Weird, I'll take a look at it over at eclipse-theia/theia-blueprint#275. We've already successfully integrated the feature in one of our projects (Electron+Browser, Windows+Ubuntu+Mac), so I'm fairly certain it works as expected.

[zhaomenghuan]

@msujew Hello，do you have a configuration for not bundling the backend? After upgrading to the latest version, my application is not running properly.

[msujew]

@zhaomenghuan You can just remove the backendConfig from the webpack.config.js of your application. That will stop the backend bundling.