Shows how to use OSGi as a platform for web services. Uses Blueprint, Declarative Services, Metatype Service, Redis and Apache CXF to demonstrate various aspects of OSGi.

Apache Karaf is used as the OSGi runtime (both shell extensions for Jedis and features for Karaf are provided).

1. Install Redis & create a sorted set to use. A quick way to do this is via a Lua script such as :

local i = 0;

while ( i < 500000 ) do 
    redis.call("zadd", 'leaderboard', i, "member_"..i) 
    i = i + 1 
end

Save this as lb.lua and then from a shell do

redis-cli --eval lb.lua

Check this worked by

redis-cli zcard leaderboard

You should see (integer) 500000

2. Install Karaf 3.0.x

Modify the Pax maven url resolver config and add the ninedemons repo. Edit the file ${KARAF_HOME}/etc/org.ops4j.pax.url.mvn.cfg and modify the value of org.ops4j.pax.url.mvn.repositories so it looks like

org.ops4j.pax.url.mvn.repositories= \
    http://ninedemons-maven-repo.s3.amazonaws.com/snapshot@snapshots, \
    .....

3. Provision Karaf

Start Karaf and install the SCR extension (used by the dummy leaderboard service) :

karaf@root> feature:install eventadmin
karaf@root> feature:install scr

Now install Apache CXF for the REST framework :

karaf@root> feature:repo-add cxf 2.7.16
karaf@root> feature:install cxf

Finally, install the leaderboards

karaf@root> feature:repo-add mvn:com.ninedemons.osgi.leaderboards/features/1.0.0-SNAPSHOT/xml/features
karaf@root> feature:install leaderboard-remoting

4. Try out the service

A users contextual leaderboard

curl http://localhost:8181/cxf/leaderboard/me/member_99

A page from the leaderboard

curl http://localhost:8181/cxf/leaderboard/page/0

A leaderboard of friends

curl "http://localhost:8181/cxf/leaderboard/friends?id=member_99&id=member_1"

Try the URLs above with both '.xml' and '.json' appended.