Hi, I'm thinking of creating a generic launcher, using a text file definition to load and start jars, allowing a Sling launcher to take over and load and start bundles once a main class is started.
Here's a rough idea - I haven't looked at Karaf closely yet, there's probably some overlap, but my idea is to create a generic Java launcher, having nothing to do with OSGi, that in turn launches an OSGi-aware main class. The launcher is a runnable jar, or a war file. It uses a text file named launch.txt to define what to launch, example below. # START launch.txt example properties: sling.home = ./sling org.apache.commons.launcher.protocols.maven.repository.1 = http://repo1.maven.org/maven2 org.apache.commons.launcher.protocols.maven.repository.2 = http://people.apache.org/repo/m2-incubating-repository protocols: # by default only the http and file protocol are provided to # load jar files, more can be added by loading protocol jars # The maven protocol, for example, grabs jar files from # repositories defined by the *.maven.repository properties # found above. jar http://some.repository/launcher-maven-protocol-1.4.2.jar md5=1231231239812cd21231987 bootstrap: # load a number of jars that are required to start the main class jar maven:org.apache.felix:org.osgi.compendium:jar:1.2.0 md5=1231231239812cd212315645 jar maven:org.apache.felix:org.osgi.core:jar:1.2.0 sha1=1231231239812cd21231123213 jar maven:org.apache.felix:org.osgi.foundation:jar:1.2.0 sha1=1231231239812cd2123112313 jar maven:org.apache.sling:org.apache.sling.launchpad.launcher:2.0.2-incubator md5=1231231239812cd2123112313 # now start the main class, from the org.apache.sling.launchpad.launcher jar main-class org.apache.sling.launchpad.launcher.Main -m launcher # The launcher stops processing here, and provides this file to the main class as its # standard input. The above launcher.Main processes the lines that follow the # above main-class statement # Load and start a few bundles, some with specific start levels bundle http://some.obr/some-bundle sha1=1231390890823121312 bundle maven:some.group:some.artifact:1.0 startlevel=2 md5=123213213984329843 # END launch.txt example Creating a launcher that will "never" change doesn't seem too hard, and then defining a Sling launchpad instance boils down to the launch.txt file. Using a text file to define bundles makes it easy for people to exchange configurations, as the text file fully defines the application assembly, based on the bundles URLs and digests. WDYT? -Bertrand
