grnhse/node-engine

A Cloud Native Buildpack for Node

Node Engine Cloud Native Buildpack

The Node Engine CNB provides the Node binary distribution. The buildpack installs the Node binary distribution onto the $PATH which makes it available for subsequent buildpacks and in the final running container. Examples of buildpacks that might use the Node binary distribution are the NPM CNB and Yarn Install CNB

Integration

The Node Engine CNB provides node and npm as dependencies. Downstream buildpacks, like Yarn Install CNB or NPM CNB, can require the node dependency by generating a Build Plan TOML file that looks like the following:

[[requires]]

  # The name of the Node Engine dependency is "node". This value is considered
  # part of the public API for the buildpack and will not change without a plan
  # for deprecation.
  name = "node"

  # The version of the Node Engine dependency is not required. In the case it
  # is not specified, the buildpack will provide the default version, which can
  # be seen in the buildpack.toml file.
  # If you wish to request a specific version, the buildpack supports
  # specifying a semver constraint in the form of "10.*", "10.15.*", or even
  # "10.15.1".
  version = "10.15.1"

  # The Node Engine buildpack supports some non-required metadata options.
  [requires.metadata]

    # Setting the build flag to true will ensure that the Node Engine
    # depdendency is available on the $PATH for subsequent buildpacks during
    # their build phase. If you are writing a buildpack that needs to run Node
    # during its build process, this flag should be set to true.
    build = true

    # Setting the launch flag to true will ensure that the Node Engine
    # dependency is available on the $PATH for the running application. If you are
    # writing an application that needs to run node at runtime, this flag should
    # be set to true.
    launch = true

Or they can require both node and npm using a Build Plan that looks like the following:

[[requires]]

  # The name of the Node Engine dependency is "node". This value is considered
  # part of the public API for the buildpack and will not change without a plan
  # for deprecation.
  name = "node"

  # The version of the Node Engine dependency is not required. In the case it
  # is not specified, the buildpack will provide the default version, which can
  # be seen in the buildpack.toml file.
  # If you wish to request a specific version, the buildpack supports
  # specifying a semver constraint in the form of "10.*", "10.15.*", or even
  # "10.15.1".
  version = "10.15.1"

  # The Node Engine buildpack supports some non-required metadata options.
  [requires.metadata]

    # Setting the build flag to true will ensure that the Node Engine
    # depdendency is available on the $PATH for subsequent buildpacks during
    # their build phase. If you are writing a buildpack that needs to run Node
    # during its build process, this flag should be set to true.
    build = true

    # Setting the launch flag to true will ensure that the Node Engine
    # dependency is available on the $PATH for the running application. If you are
    # writing an application that needs to run node at runtime, this flag should
    # be set to true.
    launch = true

[[requires]]

  # The name of the Npm dependency is "npm". This value is considered
  # part of the public API for the buildpack and will not change without a plan
  # for deprecation.
  name = "npm"

Usage

To package this buildpack for consumption:

$ ./scripts/package.sh --version <version-number>

This will create a buildpackage.cnb file under the build directory which you can use to build your app as follows: pack build <app-name> -p <path-to-app> -b build/buildpackage.cnb

buildpack.yml Configurations

In order to specify a particular version of node you can provide an optional buildpack.yml in the root of the application directory.

nodejs:
  # this allows you to specify a version constraint for the node depdendency
  # any valid semver constaints (e.g. 10.*) are also acceptable
  version: ~10

  # allow node to optimize memory usage based on your system constraints
  # bool
  optimize-memory: true

Run Tests

To run all unit tests, run:

./scripts/unit.sh

To run all integration tests, run:

/scripts/integration.sh