vladimir-lu / grapple

a minimal launcher for Java applications

grapple

• (transitive) To seize something and hold it firmly.
• (nautical) A device consisting of iron claws, attached to the end of a rope, used for grasping and holding an enemy ship prior to boarding; a grapnel or grappling iron.

Grapple - a minimal free software application launcher for Java applications

WARNING: currently alpha quality; may accidentally your cat

Description

Grapple is a launcher and updater for applications whose contents are served over HTTP. It is written in Java and primarily caters for JVM applications that also need to bundle a JVM. It may optionally be combined with Java Web Start as the initial delivery mechanism.

Goals

Grapple aims to achieve:

• Separation of system JVM from application target JVM without administrative intervention of any kind
• Simplicity of application deployment by keeping all assets (optionally) immutable

For more information, see design

Usage

To use Grapple with a JVM target follow these steps:

1. Generate two manifests for the JVM and the application using org.halfway.grapple.ManifestTool

2. Place the two directories under a HTTP server

3. Run org.halfway.grapple.Grapple as described below:

   java
       -Dgrapple.application.root=/opt/application
       -Dgrapple.application.name=application
       -Dgrapple.application.urls=http://localhost:8080/static/application
       -Dgrapple.application.jvm.urls=http://localhost:8080/static/jvm
       -Dgrapple.application.jvm.root=/opt/application-jvm
       -Dgrapple.application.jvm.main-class=my.application.Main
       -jar grapple.jar
   

Roadmap

The software is currently alpha quality and will not be considered stable until version 1.0. The following releases are planned leading up to 1.0:

• 0.8
  • initial release on github
  • travis build
• 0.9
  • RFCs for manifest format and configuration
  • Add support for creating Windows start menu shortcuts
  • Add support for logging into a file
  • Add unit tests that test the update process end-to-end using an in-process HTTP server
• 1.0
  • Add support for signed JNLP scenarios
  • Finish documentation
  • Add support for localization of messages
  • Stabilise the manifest and mandatory configuration options
  • Publish unsigned jar in maven central

After 1.0 the goal is to follow semantic versioning with respect to the manifest format.

Future work

There are items that will not be tackled by 1.0:

• UI design improvements, including testing of things like HiDPI scaling issues
• Diffing of jar files to reduce download size

Please file an issue if the above or anything else is a problem for you.

Other software

See other software for a discussion of projects that accomplish similar goals.

Contribution process

Grapple is the work of its contributors and is a free software project licensed under the LGPLv3 or later. Chapter 6 of the ØMQ guide explains why you should also pick the GPL for your next project.

If you would like to contribute please follow the C4 process.