paketo-buildpacks / sbt

A Cloud Native Buildpack that builds SBT-based applications from source

gcr.io/paketo-buildpacks/sbt

The Paketo Buildpack for SBT is a Cloud Native Buildpack that builds SBT-based applications from source.

Behavior

This buildpack will participate all the following conditions are met

• <APPLICATION_ROOT>/build.sbt exists

The buildpack will do the following:

• Requests that a JDK be installed
• Links the ~/.sbt to a layer for caching
• If <APPLICATION_ROOT>/sbt exists
  • Runs <APPLICATION_ROOT>/sbt universal:packageBin to build the application
• If <APPLICATION_ROOT>/sbt does not exist
  • Contributes SBT to a layer with all commands on $PATH
  • Runs <SBT_ROOT>/bin/sbt package to build the application
• Removes the source code in <APPLICATION_ROOT>, following include/exclude rules
• If $BP_SBT_BUILT_ARTIFACT matched a single file
  • Restores $BP_SBT_BUILT_ARTIFACT from the layer, expands the single file to <APPLICATION_ROOT>
• If $BP_SBT_BUILT_ARTIFACT matched a directory or multiple files
  • Restores the files matched by $BP_SBT_BUILT_ARTIFACT to <APPLICATION_ROOT>

Configuration

Environment Variable	Description
$BP_SBT_BUILD_ARGUMENTS	Configure the arguments to pass to build system. Defaults to universal:packageBin.
$BP_SBT_BUILT_MODULE	Configure the module to find application artifact in. Defaults to the root module (empty).
$BP_SBT_BUILT_ARTIFACT	Configure the built application artifact explicitly. Supersedes $BP_SBT_BUILT_MODULE. Defaults to target/universal/*.zip. Can match a single file, multiple files or a directory. Can be one or more space separated patterns.
$BP_SBT_REPOSITORIES_FILE	Specifies a custom location to SBT's repositories file.
$BP_INCLUDE_FILES	Colon separated list of glob patterns to match source files. Any matched file will be retained in the final image. Defaults to `` (i.e. nothing).
$BP_EXCLUDE_FILES	Colon separated list of glob patterns to match source files. Any matched file will be specifically removed from the final image. If include patterns are also specified, then they are applied first and exclude patterns can be used to further reduce the fileset.

Bindings

The buildpack optionally accepts the following bindings:

Type: dependency-mapping

Key	Value	Description
<dependency-digest>	<uri>	If needed, the buildpack will fetch the dependency with digest <dependency-digest> from <uri>

License

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

sbt's Issues

Allow users to provide global settings in a binding

Given a binding of type or kind sbt containing a global.sbt file, configure sbt to use the provided global settings.

This feature is analogous to https://github.com/paketo-buildpacks/maven#type-maven

Allow setting a SBT repositories via an env var

Describe the Enhancement

There are often times when the user/operator/stack provider would want an easy way to specify the sbt repositories to a file path in the builder/workspace which doesn't contain any credentials. For eg. changing the maven.ivy repositories.

Currently SBT BP doesn't expose a non project specific way of doing this.

Possible Solution

Allow defining a path to sbt repositories file.

Motivation

Support enterprise SBT repositories.

Make wrapper executable before invoking

SBT equivalent to paketo-buildpacks/maven#6

Support external cache location

If a user is running pack locally, or perhaps wants to do a very dangerous thing and share a cache across multiple platforms, this should be possible. If <platform>/sbt exists, it should be used for the cache.