Talk:Yum-plugin-priorities

Mmccarn 15:00, 24 November 2008 (UTC)

Odd - all problems went away after update to SME 7.4. Apparently perl-DBIx-SearchBuilder is not in the smeos repo any more (as far as I can tell), so the perl-DBIx-DBSchema requirement for perl-DBIx-SearchBuilder is met from dag with no problems.

I can't find any useful discussions about overall yum-based solutions for this type of error (low-priority repo has an update that includes a 'require' for a newer version of a file from a high-priority repo), which leads me to the following conclusions / recommendations:

1. This error will only manifest itself to idiots people like me who install experimental stuff on their servers.
2. yum-plugin-priorities should therefor be included by default, with all sme/centos repos set to priority 10
3. Potential errors should be handled in documentation, along the lines of:
   • if you install any contribs or non-sme packages using any form of --enablerepo=<xxx>, update with yum --enablerepo=* update (or separate --enablerepo=<xxx> arguments for every repo you've ever included using --enablerepo=) to make sure you get any available updates for your extra packages
   • If you get a 'missing dependancy error' from yum,
     • re-run yum manually using "--exclude <pkgname>" on the command line, replacing <pkgname> with the package that is preventing your update
     • If you suspect that the blocked update resolves a security issue, you must decide for yourself whether to compromise the original sme/centos package and force the update of the non-sme/centos package by running yum --noplugins --enablerepo=* update <pkgname>

Mmccarn 15:31, 22 November 2008 (UTC)

perl-DBIx-DBSchema

Yes - I finally figured out that perl-DBIx-DBSchema was installed when I tried to install 'Resource Tracker' - they have their own repository....

Clearly, we could choose to ignore this issue -- but just as clearly if we configure yum-plugin-priorities it will become possible to install 3rd party apps that later break yum.

In this case, perl-DBIx-DBSchema, which is not included with SME requires perl-DBIx-SearchBuilder which is included with SME - so the low priority repo locates and wants to update perl-DBIx-DBSchema, but the priorities plugin then prevents the install of the correct perl-DBIx-SearchBuilder.

We need

• a plugin, method, or option that blocks the update of packages from 3rd party repos if the new version requires a package that is included with SME / Centos that has not yet been updated.
• a way to notify users of the blocked updates so they can decide if the blocked update involves a security issue
• or documentation on how to work around this issue, along the lines of "observe the problem, identify the blocking package, update the blocking package independently using the "--noplugins" option, then finish your update

sn

yes this is a big problem

want to search or ask at the yum mailinglist, this should be a known problem

Side note on security

A major reason that I use SME server is that I feel the developers are highly security conscious, and that if I keep a SME server relatively virgin it will remain secure. I don't have the knowledge, time or experience to evaluate every package available in Linux for its security exposure level.

Is there any easy way to scan a SME server, identify any installed packages that are not considered secure by the SME developers, then modify /etc/motd and add a note to server-manager stating that "unevaluated packages are installed"?

Perhaps you can use the following audittool in your detection logic as it should report all contribs from 3d party repositories:

/sbin/e-smith/audittools/newrps

— Cactus (talk | contribs)  15:43, 22 November 2008 (UTC)

Installation

My "script" for modifying /etc/yum.conf is just my notes on how to make these changes easily and temporarily; I hadn't gotten around to making a custom template fragment yet...

Snoble 09:37, 22 November 2008 (UTC)

You should be able to use my script on 7.3 to populate the db

only difference is there will be a different fragment to modify /etc/yum.conf/something