PHP Composer Distribution Cloud Native Buildpack

This buildpack provides the composer dependency by installing the composer binary onto the build image $PATH which makes it available to subsequent buildpacks. This buildpack will not issue commands to composer (such as composer install).

A usage example can be found in the samples repository under the php/composer directory.

Detection

Will add these requires/provisions to the build plan if and only if a composer.json file is found.

Requires:

None

Provides:

• composer

Build

Will install Composer at a location on the $PATH of the build or launch image for subsequent buildpacks to use.

Integration

The PHP Composer CNB provides composer as a dependency. Downstream buildpacks can require the composer dependency by generating a Build Plan TOML file that looks like the following:

[[requires]]

    # The PHP Composer provision is named `composer`.
    # This value is considered part of the public API for the buildpack and will not 
    # change without a plan for deprecation.
    name = "composer"
    
    # The version of this buildpack.
    # This is not the version of the provided `composer` dependency.
    # If not specified the buildpack will provide the default version, which can
    # be seen in the buildpack.toml file.
    # Any valid semver constraint is acceptable.
    version = "0.1.0"

    # The PHP Composer Dist buildpack requires some additional metadata options.
    # If neither metadata.build or metadata.launch is provided, this buidpack will contribute
    # an ignored layer
    [requires.metadata]
    
        # Setting the build flag to true will ensure that Composer
        # is available on the `$PATH` for subsequent buildpacks during their
        # build phase. If you are writing a buildpack that needs to run Composer
        # during its build process, this flag should be set to true.
        build = true

        # Setting the launch flag to true will ensure that Composer
        # is available on the `$PATH` of the runtime container.
        launch = true

        # Any valid version constraint is allowed
        version = "2.2.*"

        # "version-source" will allow this buildpack to decide which "version" constraint to use
        # such as when multiple buildpacks require `composer` with version constraints
        version-source = ""

Logging Configurations

To configure the level of log output from the buildpack itself, set the $BP_LOG_LEVEL environment variable at build time either directly or through a project.toml file If no value is set, the default value of INFO will be used.

The options for this setting are:

• INFO: (Default) log information about the detection and build processes
• DEBUG: log debugging information about the detection and build processes

pack build my-app --env BP_LOG_LEVEL=DEBUG

Usage

To package this buildpack for consumption

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

This builds the buildpack's Go source using GOOS=linux by default. You can supply another value as the first argument to package.sh.

Configuration

BP_COMPOSER_VERSION

The BP_COMPOSER_VERSION variable allows you to specify a version or contraint for the composer dependency. Any valid semver range or constraint is allowed. If BP_COMPOSER_VERSION matches a version provided by this buildpack, composer will be installed regardless of what other buildpacks have set. If not provided, this buildpack will install composer if and only if a later buildpack requires composer.

BP_COMPOSER_VERSION=2.2.*

COMPOSER

The COMPOSER variable allows you to specify the filename of composer.json. When set, this buildpack will use this location instead of composer.json in the detection phase. This value must be relative to the project root.

For more information, please reference the composer docs.

COMPOSER=./somewhere/composer-other.json