The Paketo Open Liberty Buildpack is a Cloud Native Buildpack that contributes Open Liberty for Java EE support.


This buildpack will participate all the following conditions are met

  <APPLICATION_ROOT>/server.xml exists OR
  <APPLICATION_ROOT>/wlp/usr/servers/*/server.xml exists
) AND (
  Main-Class is NOT defined in the mainfest

The buildpack will do the following:

  • Requests that a JRE be installed
  • Contribute an Open Liberty runtime to wlp.install.dir
  • Create a server called defaultServer
  • Contributes web process type
  • At launch time, symlinks <APPLICATION_ROOT> to ${wlp.install.dir}/usr/servers/defaultServer/dropins/<APPLICATION_ROOT_BASENAME>.

The buildpack will support all available profiles of the two most recent versions of the Open Liberty runtime. Note that because the Open Liberty versioning scheme is not conformant semantic versioning, an Open Liberty version like is defined here as 21.0.11, and should be referenced as such.


Environment Variable Description
$BP_OPENLIBERTY_VERSION The version of Open Liberty to install. Defaults to the latest version of the runtime.
$BP_OPENLIBERTY_PROFILE The Open Liberty profile to use. Defaults to full.
$BP_OPENLIBERTY_APP_NAME If the server.xml does not specify a context root, Open Liberty will use this value as the context root. Defaults to the value of $CNB_APP_DIR, currently workspace.
$BP_OPENLIBERTY_LOG_LEVEL Sets the logging level. If not set, attempts to get the buildpack’s log level. If unable, defaults to INFO

Default Configurations that Vary from Open Liberty’s Default

By default, the Open Liberty buildpack will log in json format. This will aid in log ingestion. Due to design decisions from the Open Liberty team, setting this format to any other value will prevent all log types from being sent to stdout and will instead go to messages.log. In addition, the log sources that will go to stdout are message,trace,accessLog,ffdc,audit.

All of these defaults can be overriden by setting the appropriate properties found in Open Liberty’s documentation. They can be set as environment variables, or in bootstrap.properties.


The Open Liberty buildpack will accept a single binding of type open-liberty. There are currently two files supported in the binding:

  1. server.xml. If specified, this file will replace the defaultServer‘s server.xml and is not subject to any post-processing; therefore, any variable references therein must be resolvable.
  2. bootstrap.properties. If specified, this file will replace the defaultServer‘s bootstrap.properties. This is one place to define variables used by server.xml.

Both files are optional, as is the binding itself.


This buildpack is released under version 2.0 of the Apache License.


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