nodeengine

README

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 "15.*", "15.14.*", or even
  # "15.14.0".
  version = "15.14.0"

  # 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 "15.*", "15.14.*", or even
  # "15.14.0".
  version = "15.14.0"

  # 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

Configurations

Specifying a Node version

Specifying the Node version through buildpack.yml configuration will be deprecated in Node Engine Buildpack v1.0.0.

To migrate from using buildpack.yml please set the $BP_NODE_VERSION environment variable at build time either directly (ex. pack build my-app --env BP_NODE_VERSION=~15) or through a project.toml file

$BP_NODE_VERSION="~15"

This will replace the following structure in buildpack.yml:

nodejs:
  version: ~15

You can also specify a node version via an .nvmrc or .node-version file, also at the application directory root.

Enabling memory optimization

Enabling memory optimization through buildpack.yml configuration will be deprecated in Node Engine Buildpack v1.0.0.

To migrate from using buildpack.yml please set the $BP_NODE_OPTIMIZE_MEMORY environment variable at build time either directly (ex. pack build my-app --env BP_NODE_OPTIMIZE_MEMORY=true) or through a project.toml file

$BP_NODE_OPTIMIZE_MEMORY="true"

This will replace the following structure in buildpack.yml:

nodejs:
  optimize-memory: true

Specifying a project path

To specify a project subdirectory to be used as the root of the app, please use the BP_NODE_PROJECT_PATH environment variable at build time either directly (ex. pack build my-app --env BP_NODE_PROJECT_PATH=./src/my-app) or through a project.toml file. This could be useful if your app is a part of a monorepo.

Run Tests

To run all unit tests, run:

./scripts/unit.sh

To run all integration tests, run:

/scripts/integration.sh

Documentation

Index

• Constants
• Variables
• func Build(entryResolver EntryResolver, dependencyManager DependencyManager, ...) packit.BuildFunc
• func Detect(nvmrcParser, buildpackYMLParser, nodeVersionParser VersionParser) packit.DetectFunc
• type BuildPlanMetadata
• type BuildpackYMLParser
  • func NewBuildpackYMLParser() BuildpackYMLParser
  • func (p BuildpackYMLParser) Parse(path string) (Config, error)
  • func (p BuildpackYMLParser) ParseVersion(path string) (string, error)
• type Config
• type DependencyManager
• type EntryResolver
• type Environment
  • func NewEnvironment(logger LogEmitter) Environment
  • func (e Environment) Configure(buildEnv, launchEnv packit.Environment, path string, optimizeMemory bool) error
• type EnvironmentConfiguration
• type LogEmitter
  • func NewLogEmitter(output io.Writer) LogEmitter
  • func (e LogEmitter) Environment(buildEnv, launchEnv packit.Environment, optimizeMemory bool)
• type NodeVersionParser
  • func NewNodeVersionParser() NodeVersionParser
  • func (p NodeVersionParser) ParseVersion(path string) (string, error)
• type NvmrcParser
  • func NewNvmrcParser() NvmrcParser
  • func (p NvmrcParser) ParseVersion(path string) (string, error)
• type VersionParser

Constants

const (
	Node = "node"
	Npm  = "npm"

	DepKey             = "dependency-sha"
	NvmrcSource        = ".nvmrc"
	BuildpackYMLSource = "buildpack.yml"
	NodeVersionSource  = ".node-version"
)

Variables

var (
	MemoryAvailableScript = strings.TrimSpace(`
if [[ -z "$MEMORY_AVAILABLE" ]]; then
		memory_in_bytes="$(cat /sys/fs/cgroup/memory/memory.limit_in_bytes)"
		MEMORY_AVAILABLE="$(( $memory_in_bytes / ( 1024 * 1024 ) ))"
fi
export MEMORY_AVAILABLE
`)

	OptimizeMemoryScript = `export NODE_OPTIONS="--max_old_space_size=$(( $MEMORY_AVAILABLE * 75 / 100 ))"`
)

Functions

func Build

func Build(entryResolver EntryResolver, dependencyManager DependencyManager, environment EnvironmentConfiguration, logger LogEmitter, clock chronos.Clock) packit.BuildFunc

func Detect

func Detect(nvmrcParser, buildpackYMLParser, nodeVersionParser VersionParser) packit.DetectFunc

Types

type BuildPlanMetadata

type BuildPlanMetadata struct {
	Version       string `toml:"version"`
	VersionSource string `toml:"version-source"`
}

type BuildpackYMLParser

type BuildpackYMLParser struct{}

func NewBuildpackYMLParser

func NewBuildpackYMLParser() BuildpackYMLParser

func (BuildpackYMLParser) Parse

func (p BuildpackYMLParser) Parse(path string) (Config, error)

func (BuildpackYMLParser) ParseVersion

func (p BuildpackYMLParser) ParseVersion(path string) (string, error)

type Config

type Config struct {
	Version         string `yaml:"version"`
	OptimizedMemory bool   `yaml:"optimize-memory"`
}

type DependencyManager

type DependencyManager interface {
	Resolve(path, id, version, stack string) (postal.Dependency, error)
	Deliver(dependency postal.Dependency, cnbPath, layerPath, platformPath string) error
	GenerateBillOfMaterials(dependencies ...postal.Dependency) []packit.BOMEntry
}

type EntryResolver

type EntryResolver interface {
	Resolve(name string, entries []packit.BuildpackPlanEntry, priorities []interface{}) (packit.BuildpackPlanEntry, []packit.BuildpackPlanEntry)
	MergeLayerTypes(name string, entries []packit.BuildpackPlanEntry) (launch bool, build bool)
}

type Environment

type Environment struct {
	// contains filtered or unexported fields
}

func NewEnvironment

func NewEnvironment(logger LogEmitter) Environment

func (Environment) Configure

func (e Environment) Configure(buildEnv, launchEnv packit.Environment, path string, optimizeMemory bool) error

type EnvironmentConfiguration

type EnvironmentConfiguration interface {
	Configure(buildEnv, launchEnv packit.Environment, path string, optimizeMemory bool) error
}

type LogEmitter

type LogEmitter struct {
	// Emitter is embedded and therefore delegates all of its functions to the
	// LogEmitter.
	scribe.Emitter
}

func NewLogEmitter

func NewLogEmitter(output io.Writer) LogEmitter

func (LogEmitter) Environment

func (e LogEmitter) Environment(buildEnv, launchEnv packit.Environment, optimizeMemory bool)

type NodeVersionParser

type NodeVersionParser struct{}

func NewNodeVersionParser

func NewNodeVersionParser() NodeVersionParser

func (NodeVersionParser) ParseVersion

func (p NodeVersionParser) ParseVersion(path string) (string, error)

type NvmrcParser

type NvmrcParser struct{}

func NewNvmrcParser

func NewNvmrcParser() NvmrcParser

func (NvmrcParser) ParseVersion

func (p NvmrcParser) ParseVersion(path string) (string, error)

type VersionParser

type VersionParser interface {
	ParseVersion(path string) (version string, err error)
}