systemd vice SysV/LSB init systems - what next ?

[Nicolas Mailhot]

Le Mer 20 juillet 2011 01:12, Jeff Spaleta a écrit :
> On Tue, Jul 19, 2011 at 1:33 PM, Nicolas Mailhot
> <nicolas.mailhot at laposte.net> wrote:
>> All this code is here just to instanciate the service and do the related
>> housekeeping. It does not belong in a separate script any more or less
>> than the rest of the sysv stuff. That example just shows the sysv setup
>> was flexible enough to handle complex multi-instanciated setups and
>> systemd so far isn't
>
> It is your opinion that having init scripts potentially create
> directories … is a best practice?

As I said before, I am not particularly fond of that script, it is clearly
fugly and I would not have written it this way (to add to your list I loath
variable port numbers, it makes filtering and selinux hell, people would be
well advised to use a well-defined port on one of the numerous local ips
available instead, and map this port to a virtual ip in netfilter if it
actually needs use outside the box itself).

Nevertheless, there is nothing particularly tomcat specific here, it's mostly
the kind of generic boilerplate one needs to multi-instanciate a service :
1. find free resources not conflicting with another instance (ip, port,
socket, working directory)
2. instanciate them and apply security settings to isolate each instance properly

systemd is advertised as making it possible to get rid of all kinds of generic
shell boilerplate which is being reinvented right and left in sysv scripts.
And replace is with clean streamlined reused C implementations. Well, here is
a (particularly atrocious) example of such boilerplate. Pushing it in
/usr/sbin tomcat is not cleaning it up, it's just hiding it under the carpet.
That's exactly the contrary of systemd stated aims.

I know Fedora has not really pushed multi-instanciation before (but there are
exceptions, see clamav). But our users do need multi-instanciation and
routinely tweak our init scripts for this reason. They won't appreciate
systemd pulling the carpet under their feet. If systemd is to be adopted, it
needs to make it easier to multi-instanciate, not harder.

Not to mention that new constrains like /srv/, selinux, generalized
firewalling, frequent updates make multi-instanciating a lot harder than it
used to be so it could really use some init need to replace all the shell goo
people have to use nowadays

-- 
Nicolas Mailhot