Message Bus Hangs and NSS and LDAP
Overview
When configuring my nice shiny Scientific Linux v5.x box to authenticate via a remote LDAP server, it hangs on boot when trying to start the message bus. Why?
LDAP Config Details
/etc/nsswitch.conf:
passwd: files ldap shadow: files ldap group: files ldap
Workaround/Solution
Change the LDAP config so that nss_ldap.so's connections/queries to the remote LDAP server give up after a few seconds. To do this, put some lines in /etc/ldap.conf — which "nss_ldap" picks up:
bind_policy soft
bind_timelimit 5
timelimit 5
# ...don't recall if this one is actually needed...
Unanswered Question
Why is there an LDAP lookup in the first place, from the message bus? According to the LDAP admin, the queries are related to the dbus username — the required attributes are in (the local file) /etc/passwd, which, according to the nsswitch.conf configuration, should be consulted before LDAP.