Support service bindings for additional config files (e.g.; .npmrc)

[sermler]

Hello,

i recently tried to update to v5.0.1 but it seems, that the "heroku-preinstall" script is no longer executed before running pnpm install.
I used it like mentioned in heroku/heroku-buildpack-nodejs#363 (comment) to configure a private registry.

Is it possible to get it back?
Or alternatively the servicebindings https://github.com/buildpacks/spec/blob/main/extensions/bindings.md could be used for this.(That's the way the paketo buildpacks handle additional config files).

I can try to provide a PR for this, if this would be an option.

[sermler]

Oh i see the "heroku-preinstall" was never executed on "pnpm install", the error just occurs now because i didn't required the private repo.

Would a PR about this accepted anyway?

[colincasey]

Hi @sermler, thanks for reporting this issue. Sorry for the delayed response, I was on vacation last week 😄

For the Node.js CNB, we never ported over the heroku-preinstall or heroku-cleanup script hooks as the use cases these hooks supported can often be replaced with the addition of an inline buildpack.

Would it be possible for you to add an inline buildpack to your project.toml that runs before heroku/nodejs and configures your private registry? If not, can you provide more details around your use case around why it can only be done in a heroku-preinstall hook?

[sermler]

Hey @colincasey,
I hope you had a nice vacation 😄

Sorry, I confused heroku-preinstall with heroku-prebuild, which seems to have been ported to cnb, if I understand correctly:

buildpacks-nodejs/crates/nodejs-utils/src/package_json.rs

Line 98 in 554ec2b

scripts.push("heroku-prebuild".to_owned());

and

buildpacks-nodejs/src/pnpm_install/main.rs

Line 77 in 554ec2b

if let Some(false) = node_build_scripts_metadata.enabled {

However, since it runs before the build and not before installation, it doesn't work the way I tried. Since I specify the buildpacks as CLI parameters in my CI script, I don't have a project.toml and I haven't found a way to pass inline buildpacks via pack-cli, so I don't think this is an option for me.

As a workaround, I now create a .npmrc as part of the CI script in the workspace before running “pack build,” and delete it with “heroku-postbuild.”

My reasons for using heroku-preinstall are the same as described at heroku/heroku-buildpack-nodejs#174 and heroku/heroku-buildpack-nodejs#363.

I think a cleaner solution would be to temporarily mount configuration files with secrets so that users could use Docker/Podman secrets to provision them. Perhaps https://github.com/buildpacks/spec/blob/main/extensions/bindings.md(https://github.com/servicebinding/spec) would be an option for this. Just like the Paketo buildpacks handle it.