software-center and remove vs. purge
Hi, I recently came accross the following brainstorm.ubuntu.com idea that discusses remove vs purge in softare-center: http://brainstorm.ubuntu.com/idea/24963/ and I would like to discuss it here. Let me briefly recap the difference between the two. The removal means that the content of the package gets removed from the filesystem. With purge the package content *and* the system config files (usually in /etc) will get removed as well. Some package will also do additional removal (like removing the mythtv-database content when purging mythtv-database leading to people losing data). This is not a easy problem and we need to carefully balance the needs to keep the UI simple with the needs to keep the system from accumulating cruft. There are good suggestions in the brainstorm entry. I think that while in 99(,9 probably)% of all cases a purge is fine the cost for the error in the remaining cases can be pretty high (consider someone spending a lot of time tweaking their squid.conf). So software-center errs on the safe side and defaults to remove currently. Its difficult to tell programmatically what is going to happen when the maintainer script is called with purge as this is a shell script. Our tools can estimate what amount of data the configuration file was using (and even if the user ever modified it or not) but not what additional steps the maintainer script will take (unless of course there is not maintainer script or no purge target in it :) That being said I think we should make it easy for the user to access the purge functionality both inside software-center and computer-janitor. For software-center I would like to add a option (File/Remove with configuration). A alternative solution would be to make purge the default and have a option File/Remove but preserve the configuration). What do you think about what the default should be? For most packages purge will be fine, its just the few ones where it isn't that I'm concerned about. For computer-janitor a plugin for packages that are removed but not purged sounds appropriate. Combined with some intelligence about detecting cases that a purge is harmless (like checking for purge as a target on postrm and checking if the configuration file was actually modified) we should get most packages right. With additional data like looking at what date the package was removed we can get the remaining ones right (i.e. if it was removed 3 month ago it probably is not missed by the user). Cheers, Michael -- ubuntu-desktop mailing list ubuntu-desktop@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-desktop
Re: software-center and remove vs. purge
On mar., 2010-12-07 at 10:13 +0100, Michael Vogt wrote: computer-janitor. For software-center I would like to add a option (File/Remove with configuration). A alternative solution would be to make purge the default and have a option File/Remove but preserve the configuration). What do you think about what the default should be? Hey Michael, Being on the safe side by default seems to make sense, the issue then would be to clean the configuration of things you removed later on. I'm not sure the menu items are the best way because they are easy to miss and you not have an obvious way to get back to them. What about having a uninstalled but with configuration left category? It might not be useful enough to be a s-c category though, so what about having a menu entry clean configuration for uninstall package which would run the computer-janitor for you to do this task in this case rather? Cheers, Sebastien Bacher -- ubuntu-desktop mailing list ubuntu-desktop@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-desktop
Re: software-center and remove vs. purge
Le mardi 07 décembre 2010 à 15:27 +0100, Sebastien Bacher a écrit : On mar., 2010-12-07 at 10:13 +0100, Michael Vogt wrote: computer-janitor. For software-center I would like to add a option (File/Remove with configuration). A alternative solution would be to make purge the default and have a option File/Remove but preserve the configuration). What do you think about what the default should be? Hey Michael, Sebastien Being on the safe side by default seems to make sense, the issue then would be to clean the configuration of things you removed later on. I'm not sure the menu items are the best way because they are easy to miss and you not have an obvious way to get back to them. I completely second seb on that, being on the safe side by default seems a sane thing. Now about the removing cruft option… What about having a uninstalled but with configuration left category? I'm not about that one, seems technical and reproduce what synaptic has. It might not be useful enough to be a s-c category though, so what about having a menu entry clean configuration for uninstall package which would run the computer-janitor for you to do this task in this case rather? I would rather agree with that part of the proposal: just have this menu entry to link to computer-janitor (or have a computer-janitor view in software-center to get it more integrated) for those users rather a technical category disconnected from the rest of removing cruft on my system. Cheers Didier -- ubuntu-desktop mailing list ubuntu-desktop@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-desktop
Re: software-center and remove vs. purge
Hello Michael, thanks for the nice summary! Michael Vogt [2010-12-07 10:13 +0100]: Its difficult to tell programmatically what is going to happen when the maintainer script is called with purge as this is a shell script. Our tools can estimate what amount of data the configuration file was using (and even if the user ever modified it or not) but not what additional steps the maintainer script will take I don't think it's that easy. You can only do that with conffiles, but not with configuration files, or even data files in /var/lib (think about PostgreSQL -- purging will take your entire database into the void). I don't think this behaviour would be entirely unexpected, though. If you remove a database, then I don't think it's totally surprising that this also cleans up your data, but as you say for those 1% it's better to be safe than sorry. That being said I think we should make it easy for the user to access the purge functionality both inside software-center and computer-janitor. I like that idea, too. Thanks, Martin -- Martin Pitt| http://www.piware.de Ubuntu Developer (www.ubuntu.com) | Debian Developer (www.debian.org) -- ubuntu-desktop mailing list ubuntu-desktop@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-desktop
Re: software-center and remove vs. purge
On 07/12/10 16:10, Martin Pitt wrote: Hello Michael, thanks for the nice summary! Michael Vogt [2010-12-07 10:13 +0100]: Its difficult to tell programmatically what is going to happen when the maintainer script is called with purge as this is a shell script. Our tools can estimate what amount of data the configuration file was using (and even if the user ever modified it or not) but not what additional steps the maintainer script will take I don't think it's that easy. You can only do that with conffiles, but not with configuration files, or even data files in /var/lib (think about PostgreSQL -- purging will take your entire database into the void). I don't think this behaviour would be entirely unexpected, though. If you remove a database, then I don't think it's totally surprising that this also cleans up your data, but as you say for those 1% it's better to be safe than sorry. That being said I think we should make it easy for the user to access the purge functionality both inside software-center and computer-janitor. I like that idea, too. Thanks, Martin Whilst the idea below has nothing to do with the technical side of things, I wanted to show my idea for how it would be done in the GUI. Here ( http://i53.tinypic.com/f437ma.png ) is a screenshot of my idea. It is similiar to the widget for Shuffle Control used in Banshee's toolbar. If you click on the right of the button, it would offer a menu, to select remove or purge. Then if you click on the left it would behave as a button and do the action. I am not proposing the wording I have used in the screenshot but rather the way to go about it :) -- Andrew -- ubuntu-desktop mailing list ubuntu-desktop@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-desktop
