Weekly Changes – 08/03/2021

This week sees a big change in how we configure DICE machines using localhome, check your servers now. Full details of all changes are below…

localhome and AFS sessions

After the recent openafs problems we decided to make it easier to disable the PAM afs_session module on DICE machines where it is not required. This avoids an unnecesary dependency on the AFS service which could, at least, cause long timeouts on login. There is now a DICE_NO_AFS_SESSION macro which may be specified at the top of an LCFG profile to disable it on a per-host basis. In addition to the macro there is a dice/options/disable_afs_session.h header which can be included to achieve the same thing if that makes more sense for your machines.

Further to this we agreed that it is best to remove the afs_session module by default on machines which use localhome. For machines where you do want the afs_session module you will need to explicitly specify the new DICE_OPTIONS_LOCALHOME_WITH_AFS macro.

Users wanting to access AFS from an affected machine will now have to first manually call aklog.

squid caching for packages

Work is ongoing on adding Debian support to the package cache service, this will eventually help reduce the load on the primary package server.

The LCFG rpmaccel component schema has gained support for squid refresh patterns. These can be used to control how long the data associated with particular URIs should be cached. This week sees the introduction of the new schema and the addition of a RPMACCEL_REFRESH macro which makes it easy to add extra rules. There is a default rule for the rpmlist files used by updaterpms which prevents caching, all other files will be cached. Currently the template is still the previous one which doesn’t support refresh patterns, this will change once we have completed testing of the rules required for Ubuntu support.

remctl server

Support for Ubuntu has been added to the LCFG remctl component. In particular the component has a new cfgfile resource which can be used to control the path to the main configuration file, see bug#1271 for full details.

The Debian remctl-server package does not ship with systemd service files, to avoid having to support xinetd the service files from EL7 have been copied into LCFG resources. Basic testing suggests the service works as required.

wakeweb

The wakeweb command line utility is now available on the Ubuntu SSH and XRDP servers. Users can use this utility to remotely wake up any machines which are allocated to them.

LCFG runner component

The email message sent when an error occurs (e.g. from an error in the nightly updaterpms/apt run) now includes the hostname to make it easier to see where problems occurred.