Simple CircleCI 2.0 configuration fails for global NPM package installation

tldr - use the following prefix:

npm install --prefix=$HOME/.local --global serverless

• Replace serverless with your own global package requirements.

Background:

• After a bit of experimentation the above seems to be the cleanest way I've found.

• CircleCI's current circleci/node:lts-buster image has the following on the path:

  /home/circleci/.local/bin:/home/circleci/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

• I was unable to write to /home/circleci/bin due to blocked write permissions.

• I was able to write to /home/circleci/.local/bin
• Adding the --prefix=$HOME/.local option to npm install command means the global package is then installed into /home/circleci/.local/bin
• After install, the command, in my case serverless, is executable.

As said the Dockerfile from the top is not fully identical with the one in the CircleCI-config. In the Dockerfile the base image is node which by default runs under the root user.

The circleci/node image on the on the other hand drops to the unprivileged circleci user. So a 100% identical Dockerfile based on the node image would look like this:

FROM node:10
RUN useradd -m circleci
USER circleci
RUN npm set unsafe-perm true
RUN npm install -g '@oresoftware/[email protected]'

And with this Dockerfile the same error appears as in CircleCI.

One solution would be to use sudo, the problem with this is that you would have to use sudo on every command which makes use of the node package you installed (since with sudo it would actually be installed in the /root directory which is not accessible with the circleci user).

I think the better option would be to install the package in the circleci home directory.

{
  "version": 2,
  "jobs": {
    "build": {
      "docker": [
        {
          "image": "circleci/node:10"
        }
      ],
      "steps": [
        {
          "run": "npm set prefix=/home/circleci/npm && echo 'export PATH=$HOME/circleci/npm/bin:$PATH' >> /home/circleci/.bashrc"
        },
        {
          "run": "npm install -g --loglevel=warn '@oresoftware/[email protected]'"
        }
      ]
    }
  }
}

This way you don't have to sudo everytime you want to use the package.

On CircleCI you'd need to use sudo. The default user is circleci which has passwordless sudo access.