[Buildroot] [PATCH 1/2] dhcpcd: add SysV start-up script

[Yann E. MORIN <yann.morin.1998@free.fr>]

Thomas, Arnout,  All,

On 2017-11-04 23:22 +0100, Thomas Petazzoni spake thusly:
> On Sat, 4 Nov 2017 23:07:01 +0100, Arnout Vandecappelle wrote:
> >  Exactly. "Failure" anyway just means an error message on the console, not that
> > the system fails to boot.
> 
> Sure, but some scripts currently just "exit 0" with no error message
> whatsoever when the configuration file is missing.
> 
> So, let's summarize our policy:
> 
>  * Never check if the daemon executable is present, because that's
>    silly, Buildroot guarantees it's there.
> 
>  * If the daemon needs a configuration file, always check if it exists,
>    and if not, bail out with an error message.
> 
> But... wait, if Buildroot guarantees that it installs a configuration
> file for this daemon, having the init script check its presence is
> pretty much as silly as checking the presence of the daemon executable
> itself.
> 
> So?

  * Never check if the daemon executable is present, because that's
    silly: Buildroot guarantees it's there;

  * Never check for the daemon configuration file, because that's silly:
    Buildroot guarantees it's there;

  * Check if there is a startup-script override configuration file in
    /etc/default/<foo>, and source it if present.

The /etc/default/<foo> config file is here to override the options pased
to the daemoin, for example to add more options, or to entorely replace
them. Its format is daemon-dependent (we don't want to enforce one, at
least).

Regards,
Yann E. MORIN.

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