2.5.1+ doesn't initialize when used with azure-functions-core-tools

[CreativeTechGuy]

TLDR: Two different libraries, applicationinsights and azure-functions-core-tools both overwrite Node.js' require method, thus breaking the magic that azure-functions-core-tools is doing and preventing applicationinsights to hook into the local Azure Function server. This causes automatic logging when running Azure Functions locally to not work and getCorrelationContext() to return null.

This is an incredibly complicated issue. I feel it's best explained by tracing the code since there's a lot going on.

• The offending commit in this repo is https://github.com/microsoft/ApplicationInsights-node.js/commit/19d92af2501587459885c7b097848ed0c01f37ec. This added a dependency on @azure/opentelemetry-instrumentation-azure-sdk.
• That dependency depends on @opentelemetry/instrumentation
• Which that dependency depends on require-in-the-middle, a dependency which overwrites the require method in Node.js. Make a note of this for later.
• For applicationinsights to add the proper Azure Functions hooks, it checks if @azure/functions-core exists here
• This @azure/functions-core package doesn't actually exist in NPM or on disk, it is instead provided by azure-functions-core-tools when developing locally. It does this by overwriting the require method in Node.js such that when that specific module is requested, it provides an in-memory object as the response.
• When installing azure-functions-core-tools it will make a request to install this file as a postinstall script and unpack it into node_modules. The source relevant source code which that zip includes is for the azure-functions-nodejs-worker package.
• In that worker package, here's the code which overwrites require to supply the fake @azure/functions-core package.

Now, the problem is that there's two packages which are loaded at runtime, both overwriting a global with a custom implementation. azure-functions-core-tools is loaded first so it overwrites first, then require-in-the-middle loads second and overwrites the overwrite. Thus when applicationinsights tries to check for the existence of @azure/functions-core at runtime, it cannot find it. As a result of all of this. our calls to appinsights.getCorrelationContext() return null as it was never initialized as the Azure Function hooks were never setup.

This issue was introduced in 2.5.1 and was not an issue in 2.5.0 of applicationinsights. It's unclear which package is the root cause, it seems like both are equally to blame as they aren't playing nice with each other. Both azure-functions-core-tools and require-in-the-middle "try" to overwrite in a way to be compatible, but due to the use of the Proxy in azure-functions-core-tools it is still incompatible if loaded first.

[JacksonWeber]

Hi @CreativeTechGuy, if you want to eliminate the conflict here you could disable Azure SDK auto-instrumentation. This won't fix the core issue that the two dependencies both monkey-patch the require method but might be able to resolve your issue for now. Let me know that workaround helps, thanks!

[CreativeTechGuy]

@JacksonWeber This doesn't change anything unfortunately. The issue is that the auto-instrumentation doesn't work. So manually disabling the thing that doesn't work doesn't really do anything.

[ejizba]

I took a look and it seems like we're just waiting for the fix to propogate through various dependencies.

1. require-in-the-middle fixed this in v7.0.0
2. @opentelemetry/instrumentation updated to require-in-the-middle v7.0.0 in their v0.39.0 release
3. @azure/opentelemetry-instrumentation-azure-sdk is currently on @opentelemetry/instrumentation v0.38.0 and needs to update to v0.39.0
4. applicationinsights will need to update to the latest @azure/opentelemetry-instrumentation-azure-sdk

@JacksonWeber @hectorhdzg if you could help speed along those last two updates of packages that would be much appreciated :)

[CreativeTechGuy]

Thank you @ejizba!

[JacksonWeber]

@ejizba Absolutely. Thank you for noticing the updates in the dependency web there!

[JacksonWeber]

@CreativeTechGuy @ejizba The above issue should be resolved as our dependency on azure/opentelemetry-instrumentation has been updated and that package's dependence on require-in-the-middle and all opentelemetry packages has been updated.

[CreativeTechGuy]

Is there a plan to release that fix? It looks like it's been committed but the package hasn't been released in a few weeks.

[hectorhdzg]

@CreativeTechGuy we have a monthly release cadence in our side, we will be publishing a new version of Application Insights Node.js SDK end of next week.