The Droplet is a read-write abstraction that exposes information about the Cloud Foundry droplet that is being created. In Cloud Foundry terminology, a droplet encapsulates the filesystem and runtime configuration that will be run. Each of these things is exposed by the Droplet abstraction.
# @!attribute [r] additional_libraries
# @return [AdditionalLibraries] the shared +AdditionalLibraries+ instance for all components
attr_reader :additional_libraries
# @!attribute [r] component_id
# @return [String] the id of component using this droplet
attr_reader :component_id
# @!attribute [r] java_home
# @return [ImmutableJavaHome, MutableJavaHome] the shared +JavaHome+ instance for all components. If the
# component using this instance is a jre, then this will be an
# instance of +MutableJavaHome+. Otherwise it will be an instance of
# +ImmutableJavaHome+.
attr_reader :java_home
# @!attribute [r] java_opts
# @return [JavaOpts] the shared +JavaOpts+ instance for all components
attr_reader :java_opts
# @!attribute [r] root
# @return [JavaBuildpack::Util::FilteringPathname] the root of the droplet's fileystem filtered so that it
# excludes files in the sandboxes of other components
attr_reader :root
# @!attribute [r] sandbox
# @return [Pathname] the root of the component's sandbox
attr_reader :sandbox
# Copy resources from a components resources directory to a directory
#
# @param [Pathname] target_directory the directory to copy to. Defaults to the component's +sandbox+.
# @return [Void]
def copy_resources(target_directory = @sandbox)A helper type (JavaBuildpack::Component::AdditionalLibraries) that enables the addition of JARs to the classpath of the running droplet.
# Returns the contents of the collection as a classpath formatted as +-cp <value1>:<value2>+
#
# @return [String] the contents of the collection as a classpath
def as_classpath
# Symlink the contents of the collection to a destination directory.
#
# @param [Pathname] destination the destination to link to
# @return [Void]
def link_to(destination)The id of the component, as determined by the buildpack. This is used in various locations and is exposed to ensure uniformity of the value.
One of two helper types (JavaBuildpack::Component::ImmutableJavaHome, JavaBuildpack::Component::MutableJavaHome) that enables the mutation and retrieval of the droplet's JAVA_HOME. Components that are JREs will be given the MutableJavaHome in order to set the value. All other components will be given the ImmutableJavaHome in order to retrieve the value.
# Returns the path of +JAVA_HOME+ as an environment variable formatted as +JAVA_HOME=$PWD/<value>+
#
# @return [String] the path of +JAVA_HOME+ as an environment variable
def as_env_var
# Execute a block with the +JAVA_HOME+ environment variable set
#
# @yield yields to block with the +JAVA_HOME+ environment variable set
# @return [Object] the returned value of the block
def do_with
# @return [String] the root of the droplet's +JAVA_HOME+ formatted as +$PWD/<value>+
def root
# Sets the root of the droplet's +JAVA_HOME+
#
# @param [Pathname] value the root of the droplet's +JAVA_HOME+
def root=(value)A helper type (JavaBuildpack::Component::JavaOpts) that enables the addition of values to +JAVA_OPTS+. The add_javaagent, add_system_property, and add_option method all inspect that value to determine if it is a Pathname. If it is, the value is converted so that it is relative to the root of the droplet.
# Adds a +javaagent+ entry to the +JAVA_OPTS+. Prepends +$PWD+ to the path (relative to the droplet root) to
# ensure that the path is always accurate.
#
# @param [Pathname] path the path to the +javaagent+ JAR
# @return [JavaOpts] +self+ for chaining
def add_javaagent(path)
# Adds a system property to the +JAVA_OPTS+. Ensures that the key is prepended with +-D+. If the value is a
# +Pathname+, then prepends +$PWD+ to the path (relative to the droplet root) to ensure that the path is always
# accurate. Otherwise, uses the value as-is.
#
# @param [String] key the key of the system property
# @param [Pathname, String] value the value of the system property
# @return [JavaOpts] +self+ for chaining
def add_system_property(key, value)
# Adds an option to the +JAVA_OPTS+. Nothing is prepended to the key. If the value is a +Pathname+, then prepends
# +$PWD+ to the path (relative to the droplet root) to ensure that the path is always accurate. Otherwise, uses
# the value as-is.
#
# @param [String] key the key of the option
# @param [Pathname, String] value the value of the system property
# @return [JavaOpts] +self+ for chaining
def add_option(key, value)
# Returns the contents as an environment variable formatted as +JAVA_OPTS="<value1> <value2>"+
#
# @return [String] the contents as an environment variable
def as_env_varThe root of the filesystem for the droplet. This is a JavaBuildpack::Util::FilteringPathname to ensure that this view of the filesystem includes only the users's code and the files in the component's sandbox. It can be safely assumed that other Pathnames based on this root will accurately reflect filesystem attributes for those files.
The root of the filesystem for the component's sandbox. The sandbox is a portion of the filesystem that a component can work in that is isolated from all other components. This is a JavaBuildpack::Util::FilteringPathname to ensure that this view of the filesystem includes only the the component's sandbox. It can be safely assumed that other Pathnames based on this sandbox will accurately reflect filesystem attributes for those files.
Copy the contents of the component's resources directory if it exists. The components resources directory is found in the <buildpack-root>/resources/<component-id>. This is typically used to overlay the contents of the resources directory onto a component's sandbox.