Allow disabling New Relic dependency at build-time

[arbrandes]

(This is a synthesis of the original report in the forum.)

It turns out that that @newrelic/publish-sourcemap is not distributed with a open-source-compatible license, and thus can't be distributed legally. From its package.json:

"license": "New Relic proprietary"

While #215 introduced an ENABLE_NEW_RELIC runtime environment variable, it only configures whether the services will be used; New Relic is still baked into the build. If the build is then distributed as part of an image (say, a Tutor or Bitnami image), this becomes a potential legal problem.

We need to find a reasonable way to make the @newrelic/publish-sourcemap dependency optional.

[ghassanmas]

I can suggest the following (not tested though)

1. Add the depenecy to optionaldependencies in package.josn
2. When intsalling use the flag npm install --omit=optional
3. Any app/lib depends on frontend-build once it uses the version after step 2, then it will not have it.

However this might break, the workflow of 2U, since then need to be manualy installed to use @edx/new-relic-source-map-webpack-plugin . A workaround of this can be:

1. To release two sub versions of each frontend-build release, one with it and one without it.
2. To modifiy the codebase of @edx/new-relic-source-map-webpack-plugin so that its doesn't use new relic library, rather it uploads the assets using native API, or any library that is FOSS.

[Mashal-m]

We have implemented these suggestions and implemented code change suggestions given in the form.
Installing dependency as an optional dependency generates an error in frontend-build while running build or test and every MFE is using frontend-build.

• Releasing two versions would not be convenient since the usage of frontend-build is vast
• We have to figure out an alternative of https://github.com/edx/new-relic-source-map-webpack-plugin cause @newrelic/publish-sourcemap is installed in it directly.

[ghassanmas]

@Mashal-m I think an alternative approach could be to upload source map using native API:

https://docs.newrelic.com/docs/browser/new-relic-browser/browser-pro-features/upload-source-maps-api/#curl-post
Newrelic has an example about using curl linked above

curl -H "Api-Key: YOUR_NEW_RELIC_USER_API_KEY" \ 
    -F "sourcemap=@SOURCE_MAP_PATH" \ 
    -F "javascriptUrl=JS_URL" \ 
    -F "releaseId=YOUR_RELEASE_ID" \ 
    -F "releaseName=YOUR_UI_PAGE" \
    -F "repoUrl=GITHUB_REPOSITORY_URL" \
    -F "buildCommit=GIT_BUILD_COMMIT_HASH" \

https://sourcemaps.service.newrelic.com/v2/applications/YOUR_NEW_RELIC_APP_ID/sourcemaps

Which to me looks like what @newrelic/publish-sourcemap is doing here

        publishSourcemap(
            {
                sourcemapPath,
                javascriptUrl,
                applicationId,
                apiKey,
                releaseName,
                releaseId,
            },

ref

I think there must many libraries or even a native module in NodeJS that could replicate curl.