Hey there, let's figure out why your npm command is missing even after setting up Node.js in your before_script. The ruby:2.5.5 base image doesn't come with Node.js pre-installed, so the issue likely lies in how you're installing Node.js or ensuring it's added to your shell's PATH. Here are actionable steps to fix this:

1. Validate Your Node.js Installation Steps #

The default apt packages for Node.js in Debian-based images (like ruby:2.5.5) can be outdated or not properly linked. Instead, use the official NodeSource installation script to get a reliable setup:

before_script:
  # Update package lists
  - apt-get update -qq
  # Install dependencies for NodeSource script
  - apt-get install -y -qq curl
  # Add NodeSource repo for a Node.js version compatible with eslint@4.6.1
  - curl -fsSL https://deb.nodesource.com/setup_12.x | bash -
  # Install Node.js and npm
  - apt-get install -y nodejs
  # Verify npm is accessible
  - npm --version
  # Run your global install command
  - npm -g install eslint@v4.6.1 ember-cli yarn@v1.1.0 bower

This script ensures Node.js and npm are installed correctly and added to your system PATH automatically.

2. Debug PATH and npm Location #

If you still run into issues, add debug commands to your before_script to pinpoint where things are going wrong:

before_script:
  # ... your existing installation steps ...
  # Check if npm exists on the system
  - which npm
  # Print the current PATH to see if npm's directory is included
  - echo $PATH

• If which npm returns no output, Node.js/npm didn't install successfully—double-check your installation commands.
• If it returns a path but that path isn't in $PATH, manually add it:

  - export PATH=$PATH:/path/to/npm/directory
  

3. Use a Pre-Configured Image (Alternative) #

If you want to skip manual installation, use a Docker image that includes both Ruby 2.5.5 and Node.js. You can either:

• Build your own custom image with both dependencies, or
• Use a community-maintained image. For example:

  # Use an image with Ruby 2.5 and Node.js pre-installed
  image: jitesoft/ruby-node:2.5-node12
  before_script:
    # Verify both Ruby and Node.js are available
    - ruby --version
    - npm --version
    - npm -g install eslint@v4.6.1 ember-cli yarn@v1.1.0 bower
  

4. Fix Global npm Permissions (Optional) #

Sometimes global npm installs fail due to permission issues (even if npm is found). To avoid this, configure npm to use a user-specific global directory:

before_script:
  # ... install Node.js ...
  # Create a custom npm global directory
  - mkdir -p ~/.npm-global
  # Configure npm to use this directory
  - npm config set prefix '~/.npm-global'
  # Add the directory to PATH
  - export PATH=~/.npm-global/bin:$PATH
  # Run your global install
  - npm -g install eslint@v4.6.1 ember-cli yarn@v1.1.0 bower

Start with the NodeSource installation method—it's the most reliable for getting a working Node.js/npm setup in Debian-based images. The debug commands will help you quickly spot if PATH is the issue or if installation is failing silently.

内容的提问来源于stack exchange，提问作者Daniel