Chmod fails when running as non-root user

[cz4rny]

This buildpack runs chmod on the project's directory.

Expected Behavior

Buildpacks is able to continue on userspace (non-root) execution.

Current Behavior

Fails on chmod, e.g.:

Paketo NPM Install Buildpack 0.10.0
  Resolving installation process
    Process inputs:
      node_modules      -> "Not found"
      npm-cache         -> "Not found"
      package-lock.json -> "Found"
    Selected NPM build process: 'npm ci'
  Executing build environment install process
    Running 'npm ci --unsafe-perm --cache /layers/paketo-buildpacks_npm-install/npm-cache'
      Completed in 35.006s
  Configuring build environment
    NODE_ENV -> "development"
    PATH     -> "$PATH:/layers/paketo-buildpacks_npm-install/build-modules/node_modules/.bin"
  Generating SBOM for /layers/paketo-buildpacks_npm-install/build-modules
chmod /builds/p2s/gp2s-search/gp2s-search-frontend: operation not permitted

Possible Solution

Continue if chmod failed.

Steps to Reproduce

Run the buildpack with non-root privileges, i.e. a .gitlab-ci.yaml

stages:
  - build

default:
  tags:
    - linux
    - amd64
    - docker
 
build-image:
  stage: build
  image: paketobuildpacks/builder:full
  # Access to GitLab Container Registry for Paketo lifecycle
  before_script:
    - mkdir ~/.docker
    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_JOB_TOKEN\"}}}" >> ~/.docker/config.json
  variables:
    PLATFORM_DIR: /tmp/platform
  script:
    # creator binary doesn't read environment variables, but reads platform files.
    # Defining variables as per the the Platform Interface
    # https://github.com/buildpacks/spec/blob/main/platform.md#user-provided-variables
    - cp -r /platform "$PLATFORM_DIR"
    - echo build > "$PLATFORM_DIR/env/BP_NODE_RUN_SCRIPTS"
    - /cnb/lifecycle/creator
      -platform "$PLATFORM_DIR"
      -app=.
      $CI_REGISTRY_IMAGE:latest

Motivations

I'd like to be able to use newer paketo buildpacks in userspace builds.

[cz4rny]

It's a direct consequence of the #362 PR.

I'm not sure that the requirement of group-writeable should be done by the npm-install (this) buildpack. If that's a global buildpack feature I would assume that the projectPath directory should be made group-writable on creation. Which I don't believe happens in this buildpack.

[ryanmoran]

@cz4rny did #373 end up resolving this issue for you?

[cz4rny]

@ryanmoran Not sure if this particular one, but after the paketo images have been rebuilt within a week, npm started to work again.