Support instrumentation of express when using ESModules

[tobiasmuehl]

• This only affects the JavaScript OpenTelemetry library

As explained in the docs there is experimental support for projects that use ES Modules as well as a sample app with a http server. This all works great until Node 18.

Using express instead of http doesn't work though. I found a WIP to make express work (stale PR) but it doesn't seem to be completed:

It moans about the module loading order, even though in the sample app @opentelemetry/instrumentation-express is clearly loaded before express.

❯ yarn start-express
yarn run v1.22.21
$ node --experimental-loader=@opentelemetry/instrumentation/hook.mjs ./build/express.js
(node:48798) ExperimentalWarning: Custom ESM Loaders is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
@opentelemetry/api: Registered a global for diag v1.7.0.
@opentelemetry/api: Registered a global for trace v1.7.0.
@opentelemetry/api: Registered a global for context v1.7.0.
@opentelemetry/api: Registered a global for propagation v1.7.0.
@opentelemetry/instrumentation-express Module express has been loaded before @opentelemetry/instrumentation-express so it might not work, please initialize it before requiring express
Applying patch for express@4.18.2
hello!
No modules instrumentation has been defined for 'test-autoinstrumentions@0.0.1', nothing will be patched
Now listening on: http://0.0.0.0:3000/

Are there plans in place to support express using esm?

Likely related:

• feat(instrumentation): add support for esm module #2846
• Provide working TypeScript / ESM examples #4392
• @opentelemetry/instrumentation _onRequire does not receive the actual import name #4437
• coordinate first pass at ESM support for all instrumentations opentelemetry-js-contrib#1942

[tobiasmuehl]

Duplicate of open-telemetry/opentelemetry-js-contrib#1849

[tobiasmuehl]

🎉 I found a working solution here! My project is using esm and I switched my runtime from node to jiti and NOW EVERYTHING JUST WORKS!!!!!! even works on node20

If we are living in a simulation then this is a complete cheat code 🥷🏼