CentOS - Jul 2017 - doing something before everything else

I want to run a script before systemd starts doing stuff but I cant find
anything online about how that could happen. It seems /etc/rc.local is
depreciated now?

On Jul 22, 2017, at 8:28 AM, Andrew Holway <andrew.holway at gmail.com>
wrote:
> I want to run a script before systemd starts doing stuff but I cant find
> anything online about how that could happen. It seems /etc/rc.local is
> depreciated now?
You can?t run anything before systemd starts, since it is started by the kernel
before the local filesystems have been mounted.

/etc/rc.d/rc.local still runs, but it is a systemd service run as
rc-local.service, contingent on /etc/rc.d/rc.local existing and being
executable.

Now, if you want to run something before systemd starts other services, you need
to create your own systemd unit, and set up dependencies such that the service
starts before those services.  For example, you?d put
"Before=network-pre.target? in the [Unit] section if you wanted your
service to start before the network was brought up.  For what it?s worth,
rc-local.service has a dependency that actually starts it *after* the network
service comes up, so it starts later in the startup anyway.


--
Jonathan Billings <billings at negate.org>

Ok, great I have an rc-local working but now I have a problem that Jenkins
is starting up before / during the rc-local is running.

Jenkins is shipping with an init script. I want to put a
"Before=jenkins.service" in rc-local but Jenkins doesnt have a service
file....

How can I ensure that rc-local is running before the Jenkins init?

Thanks,

Andrew

On 22 July 2017 at 14:06, Jonathan Billings <billings at negate.org>
wrote:
> On Jul 22, 2017, at 8:28 AM, Andrew Holway <andrew.holway at
gmail.com>
> wrote:
> > I want to run a script before systemd starts doing stuff but I cant
find
> > anything online about how that could happen. It seems /etc/rc.local is
> > depreciated now?
>
> You can?t run anything before systemd starts, since it is started by the
> kernel before the local filesystems have been mounted.
>
> /etc/rc.d/rc.local still runs, but it is a systemd service run as
> rc-local.service, contingent on /etc/rc.d/rc.local existing and being
> executable.
>
> Now, if you want to run something before systemd starts other services,
> you need to create your own systemd unit, and set up dependencies such that
> the service starts before those services.  For example, you?d put
> "Before=network-pre.target? in the [Unit] section if you wanted your
> service to start before the network was brought up.  For what it?s worth,
> rc-local.service has a dependency that actually starts it *after* the
> network service comes up, so it starts later in the startup anyway.
>
>
> --
> Jonathan Billings <billings at negate.org>
>
>
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