I have created an Ubuntu package to install my RCP app. The installed files are owned by root. Is it possible for a user to subsequently install updates through P2? Documentation about Eclipse multi-user installs suggests that it is possible, along with the answer to this question.
However, when I start up the application, it does not automatically check for updates as usual, and the Update Site that I had specified in p2.inf is not listed in the "Install New Software..." dialog.
Using the -configuration or -data runtime options did not help.
I can make it work with a hack by running sudo chown -R <my_username> /opt/<my_app_installation>. When I subsequently launch the application, it does properly check for updates on startup, and my update site is properly listed in the "Install New Software..." dialog. Certainly I would prefer that whatever data it is writing to that installation directory be instead written to the user's home directory.
Supplementary info:
Here is a list of files and folders that showed up in my installation directory only after the directory was given ownership by <my_username> and the program was run.
/opt/<my_app_installation>/configuration/org.eclipse.core.runtime
/opt/<my_app_installation>/configuration/org.eclipse.equinox.app
/opt/<my_app_installation>/configuration/org.eclipse.osgi
/opt/<my_app_installation>/p2/org.eclipse.equinox.p2.engine/profileRegistry/profile.profile/1339896994308.profile.gz
/opt/<my_app_installation>/p2/org.eclipse.equinox.p2.engine/profileRegistry/profile.profile/.data/.settings/org.eclipse.equinox.p2.ui.sdk.prefs
/opt/<my_app_installation>/p2/org.eclipse.equinox.p2.engine/profileRegistry/profile.profile/.data/.settings/org.eclipse.equinox.p2.ui.sdk.scheduler.prefs
/opt/<my_app_installation>/p2/org.eclipse.equinox.p2.repository
More experimental results:
Even with a writable (chown'd) installation directory, no files are placed there when the
-configuration $HOME/.my_app_files runtime option is supplied.
There are lots of limitation of p2 itself for share install. AFAIK there is no significant improvement in latest release Juno as well.
But a guy from Redhat is working on p2 install with RPM package, you can read his progress in his blog post. The work and idea could be shared with Debian package.