[Freeipa-devel] error handling in httpd.service and ipa-httpd-kdcproxy

[Simo Sorce]

On Tue, 2015-07-07 at 08:48 -0400, Nathaniel McCallum wrote:
> > On Jul 6, 2015, at 11:35 AM, Christian Heimes <cheimes at redhat.com> wrote:
> > 
> > Hello,
> > 
> > I like to ask for your opinion regarding the pre-exec hook
> > 'ipa-httpd-kdcproxy' in httpd.service. Alex has asked me to handle error
> > cases like LDAP connection timeout more gracefully. At the moment any
> > error causes the script to return a non-zero exit code. This breaks the
> > service and apparently also offline RPM upgrades.
> > 
> > How should I handle error cases? I can change httpd.service to simply
> > ignore the exit code of ipa-httpd-kdcproxy. But that might lead to an
> > invalid state. I could modify the script to catch connection errors and
> > to disable kdcproxy in case of an error.
> > 
> > The options are:
> > 
> > 1) httpd.service ignores exit code of ipa-httpd-kdcproxy
> > 2) ipa-httpd-kdcproxy removes kdcproxy config file in case of a
> > connection error
> > 3) 1 + 2
> > 
> > What do you think?
> 
> If ipa-httpd-kdcproxy cannot contact LDAP, kdcproxy MUST NOT be
> enabled. So #2.
> 
> However, ipa-httpd-kdcproxy should leave error codes to real
> catastrophic failures and http.service should be aware of these. So
> not #1.
> 
> Nathaniel
> 

IMO it is ok for httpd to fail to start if the kdc-proxy cannot contact
LDAP, because other stuff will fail too if that's the case anyway.

In fact I had to change my replica promotion patches to account for this
as it was failing here, for various reasons, on one restart during the
install. :-)

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York