Best way to make a machine boot with or without a Internet connection

[Polytropon]

On Sat, 8 Aug 2020 05:40:23 -0400, Jerry wrote:
> On Fri, 7 Aug 2020 21:19:45 +0200, Polytropon stated:
> >On Fri, 7 Aug 2020 14:54:13 -0400, Aryeh Friedman wrote:
> >> On Fri, Aug 7, 2020 at 1:24 PM Mario Lobo <lobo at bsd.com.br> wrote:
> >>   
> >> > On Thu, Aug 6, 2020 at 6:20 PM Aryeh Friedman
> >> > <aryeh.friedman at gmail.com> wrote:
> >> >  
> >> > > Due to storm related damage my ISP went out for a few (12) hours
> >> > > earlier  
> >> > in  
> >> > > the week and while I got it usable without a Internet connection
> >> > > by  
> >> > putting  
> >> > > everything in my LAN in /etc/hosts (I also run a local_unbound
> >> > > --> local bind9 on my file server which I have created a zone
> >> > > file for the LAN machines also), but it was very slow in booting
> >> > > due to ntpdate, tomcat  
> >> > and  
> >> > > sendmail not being to connect to the Internet for either forward
> >> > > or  
> >> > reverse  
> >> > > DNS.   I don't want to turn these services off, but I want to be
> >> > > able to  
> >> > do  
> >> > > a normal boot (no long hangs) if the ISP goes down again.   What
> >> > > is the best way to do this?
> >> > >
> >> > > --
> >> > > Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org
> >> > > _______________________________________________
> >> > > freebsd-questions at freebsd.org mailing list
> >> > > https://lists.freebsd.org/mailman/listinfo/freebsd-questions
> >> > > To unsubscribe, send any mail to "
> >> > > freebsd-questions-unsubscribe at freebsd.org"
> >> > >  
> >> >
> >> > This is a long shot but perhaps you could find a way to start these
> >> > services in the background (&).
> >> >  
> >> 
> >> Given they are done by /etc/rc based on rc.onf not likely  
> >
> >The "problem" is that rc, in combination with rc.conf and
> >the responsible rc.d/ scripts, determines the order in which
> >certain services have to be started. A workaround would be
> >to use /etc/rc.local to manually do what rc would do with
> >its internal logic. Using this approach, you could set the
> >exact order as well as tests for "is currently connected
> >to the Internet", starting all subsequent tasks that do
> >require an online connection. You would put the first
> >steps into the background, using &, and you could then
> >even invoke "service netif start" (or parts thereof),
> >followed by your own services (such as ntp, webserver,
> >mailserver). Such a mechanism could be configured to
> >set a flag, for example stupidly simple as a "lock file",
> >and repeat to test for Internet availability until the
> >Internet becomes available - then stop. Some further
> >logic could be added to check if the connection stays
> >alive, and if it goes down, stop the services, remove
> >the lock file, and keep trying at a specified interval.
> >
> >Of course, this is all manual stuff, nothing is provided
> >by the OS to handle this in an appropriate fashion and
> >doesn't even look right... ;-)
> 
> I saw something on the web a while ago that sort of addressed this sort
> of problem. The user ran a script via cron on boot-up that checked for
> a specific conditions then started 'monit' to start the appropriate
> applications.

If I remember correctly, systemd is _the_ tool to deal with
this kind of situation... ;-)



-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...