Manage Node.js versions

Each Platform.sh container image includes a specific language in a specific version. A set of dependencies is also provided based on that language version. This ensures that your application container is as small and efficient as possible.

Therefore, by default, when you use a Platform.sh container image, you use the Node.js version that’s included in that image, if any.

If you want to use a different Node.js version, use a version manager to install it yourself. You can use one of the following version managers:

• Use n
• Use nvm

Both of the recommendations use a .nvmrc file to specify the desired Node.js version. You could also specify a different file or use environment variables.

Use n

The n package works for various Unix-like systems, including Windows Subsystem for Linux.

1. Add the desired Node.js version to your environment using .nvmrc, .n-node-version, .node-version, or package.json.

   • .nvmrc
   • .n-node-version/.node-version
   • package.json

   Create a .nvmrc file in your app root:

   .nvmrc

   v16.13.2

   Create a .n-node-version or .node-version file in your app root:

   .n-node-version or .node-version

   16.13.2

   Add an engines.node property to your package.json. This property accepts either an exact version or a range:

   package.json

   {
     "engines": {
       "node": ">=0.10.3 <15"
     }
   }

2. Add it as a dependency:

dependencies:
    nodejs:
        n: "*"

Adding it as a dependency ensures it’s cached for future builds.

3. Set the location of the n files using the N_PREFIX environment variable:

variables:
    env:
        N_PREFIX: /app/.global

4. Install the specified version of Node.js in a build hook:

hooks:
    build: |
        # Exit the hook on any failure
        set -e

        # Install the version specified in the .nvmrc file
        n auto

        # Reset the location hash to recognize the newly installed version
        hash -r        

Now your hooks should be able to use the specified version of Node.js. You can verify this by running node -v.

Your final app configuration should look something like this:

name: app
type: 'python:3.9'
dependencies:
    nodejs:
        n: "*"

variables:
    env:
        N_PREFIX: /app/.global

hooks:
    build: |
        # Exit the hook on any failure
        set -e

        # Install the version specified in the .nvmrc file
        n auto

        # Reset the location hash to recognize the newly installed version
        hash -r        

Use nvm

Node Version Manager (nvm) is a bash script for managing Node.js versions.

You can use it to:

• Make a specific version available in the build and optionally the runtime container.
• Control the specific versions to be installed with environment variables, meaning you can also have different versions in different environments.

To use nvm, follow these steps:

1. Define which nvm version to use using an environment variable. Add it to your app configuration:

variables:
    env:
        # Update for your desired NVM version.
        NVM_VERSION: v0.39.3

2. Define your desired Node.js version using an environment variable. For your base version, set it in your app configuration:

variables:
    env:
        # Update these for your desired NVM and Node versions.
        NVM_VERSION: v0.39.3
        NODE_VERSION: v18.14.2

To get different versions in different environments, set environment-specific variables.

3. Add a .nvm directory to your cache in your build hook:

hooks:
    build: |
        set -e
        unset NPM_CONFIG_PREFIX
        export NVM_DIR="$PLATFORM_APP_DIR/.nvm"

        # Link cache with app
        if [ ! -d "$PLATFORM_CACHE_DIR/.nvm" ]; then
            mkdir -p $PLATFORM_CACHE_DIR/.nvm
        fi
        ln -s $PLATFORM_CACHE_DIR/.nvm $NVM_DIR        

rsync -av $PLATFORM_CACHE_DIR/.nvm $PLATFORM_APP_DIR

4. Use the cache directory and install based on the variables if not present:

hooks:
    build: |
        ...
        # Check for Node.js version and install if not present
        if [ ! -d "$PLATFORM_CACHE_DIR/.nvm/versions/node/$NODE_VERSION" ]; then

            # Get nvm install script if correct version not present
            export NVM_INSTALL_FILE="${PLATFORM_CACHE_DIR}/nvm_${NVM_VERSION}_install.sh"
            if [ ! -f "$NVM_INSTALL_FILE" ]; then
                wget -nc -O "$NVM_INSTALL_FILE" "https://raw.githubusercontent.com/nvm-sh/nvm/$NVM_VERSION/install.sh"
            fi

            # Install, automatically using NODE_VERSION
            bash $NVM_INSTALL_FILE
        fi

        # Activate nvm
        [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"

        # Use the specified version
        nvm use "$NODE_VERSION"        

5. Optional: To use the specified Node.js version in the runtime container and not just the build, activate nvm via script:

   .environment

   unset NPM_CONFIG_PREFIX
   export NVM_DIR="$PLATFORM_APP_DIR/.nvm"
   [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"

Your final app configuration should look something like the following:

name: app
type: 'python:3.9'
variables:
    env:
        # Update these for your desired NVM and Node versions.
        NVM_VERSION: v0.39.3
        NODE_VERSION: v18.14.2
hooks:
    build: |
        set -e
        unset NPM_CONFIG_PREFIX
        export NVM_DIR="$PLATFORM_APP_DIR/.nvm"

        # Link cache with app
        if [ ! -d "$PLATFORM_CACHE_DIR/.nvm" ]; then
            mkdir -p $PLATFORM_CACHE_DIR/.nvm
        fi
        ln -s $PLATFORM_CACHE_DIR/.nvm $NVM_DIR
        # Check for Node.js version and install if not present
        if [ ! -d "$PLATFORM_CACHE_DIR/.nvm/versions/node/$NODE_VERSION" ]; then

            # Get nvm install script if correct version not present
            export NVM_INSTALL_FILE="${PLATFORM_CACHE_DIR}/nvm_${NVM_VERSION}_install.sh"
            if [ ! -f "$NVM_INSTALL_FILE" ]; then
                wget -nc -O "$NVM_INSTALL_FILE" "https://raw.githubusercontent.com/nvm-sh/nvm/$NVM_VERSION/install.sh"
            fi

            # Install, automatically using NODE_VERSION
            bash $NVM_INSTALL_FILE
        fi

        # Activate nvm
        [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"

        # Use the specified version
        nvm use "$NODE_VERSION"