Error: Cannot find module './Instrumentation.js' when running frontend service for local development

[kodayashi]

Bug Report

Which version of the demo you are using?

main (latest)

Symptom

I'm trying to follow the README for running the frontend service locally. After running

docker compose run --service-ports -e NODE_ENV=development --volume $(pwd)/src/frontend:/app --volume $(pwd)/pb:/app/pb frontend sh

I get this error:

Error: Cannot find module './Instrumentation.js'
Require stack:

• internal/preload
  at Function.Module._resolveFilename (node:internal/modules/cjs/loader:956:15)
  at Function.Module._load (node:internal/modules/cjs/loader:804:27)
  at Module.require (node:internal/modules/cjs/loader:1028:19)
  at Module._preloadModules (node:internal/modules/cjs/loader:1303:12)
  at loadPreloadModules (node:internal/bootstrap/pre_execution:583:5)
  at prepareMainThreadExecution (node:internal/bootstrap/pre_execution:95:3)
  at node:internal/main/run_main_module:7:1 {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ 'internal/preload' ]
  }

It looks like npm start is being run (per package.json) as opposed to npm dev. Am I doing something wrong here?

Reproduce

Just follow the instructions for running the frontend service locally in the README file.

[julianocosta89]

Are you running the command from the root folder of the project?
I mean not in the src/frontend folder.

[kodayashi]

@julianocosta89 - Correct, I'm running it from the root folder.

[julianocosta89]

Cool, just to be sure.
I'll try to reproduce.
Thanks for reporting it!

[julianocosta89]

I'm on the road ATM, I will take a look later.
Maybe @xoscar has an idea of what may be the root cause of that.

[kodayashi]

Thanks @julianocosta89. @xoscar all I can tell at this point is that npm is being run in production mode as opposed to dev. In package.json, there's the requirement for ./Instrumentation.js in "start" (which is referenced in the error above)

"start": "node --require ./Instrumentation.js server.js"

Whereas "dev" in package.json is what we're looking to run from what I can tell as it has the correct relative path to Instrumentation.js:

"dev": "npm run grpc:generate && NODE_OPTIONS='-r ./utils/telemetry/Instrumentation.js' next dev"

So, I think the answer lies in understanding why start is firing off instead of dev when running "docker compose run..." command in the frontend README file.

[xoscar]

Oh I think it's because a change was made to move away from CMD in the frontend docker file to use ENTRYPOINT instead. And the problem with that is that it doesn't allow for command overwrite in this case when running the container it will always run npm start @julianocosta89 changes https://github.com/open-telemetry/opentelemetry-demo/pull/342/files

[julianocosta89]

Also, @puckpuck do you see any issue if we return the frontend to CMD instead of ENTRYPOINT.
I've tested locally and changing it back to CMDsolves the issue.

[puckpuck]

The only issue I see is consistency with the other services, which all use ENTRYPOINT

[julianocosta89]

@puckpuck if consistency is the only issue, I'll go ahead and send a PR to use CMD as this solves the issue.

[julianocosta89]

Hello all, I've just sent a PR fixing this :)