Can't echo to console from dracut module

I have a custom dracut module installed as a pre-mount hook (for Fedora 
18).  This shell script needs to echo some messages to the console, but 
I'm having no luck making that happen.  I've tried:
echo foo
echo foo > /dev/console
echo foo > /dev/kmsg
. /lib/dracut-lib.sh
info foo
. /lib/dracut-lib.sh
export DRACUT_QUIET="no"
/bin/plymouth --hide-splash
info foo

At various times, I've tried booting with rd.info=1, but my final solution 
needs to not require that.  All of these things work as expected from the 
emergency_shell (reached by passing rd.break on the cmd-line).  I've 
looked at that function and haven't seen what I'm missing.  I'm starting 
to suspect the shell works because of the special setup in the 
dracut-emergency.service systemd unit, but haven't yet tried retooling 
things so that my hook scripts becomes not much more than a 'systemctl 
start mycustom.service', which in turn minics dracut-emergency.service but 
instead of a user shell, calls another shell script with the bulk of 
what's presenty in my hook script.

Is there a simpler way or anybody know what I'm doing wrong or need to do 
differently?  Given that I'm doing this all in a LiveOS image, my 
turn-around time for testing is rather slow and tedious.
--
John Florian

[Brian C. Lane]

On Fri, Mar 08, 2013 at 02:55:40PM -0500, [e-mail] wrote:
> I have a custom dracut module installed as a pre-mount hook (for Fedora 
> 18).  This shell script needs to echo some messages to the console, but 
> I'm having no luck making that happen.  I've tried:

This is similar to what we ran into with checkisomd5, now that systemctl
is being used by dracut you need to setup a service with access to the
console in order for anything to be output (or input).

The service file for that looks like this:

[Unit]
Description=Media check on %f
DefaultDependencies=no
Before=shutdown.target

[Service]
Type=oneshot
RemainAfterExit=no
ExecStart=/bin/checkisomd5 --verbose %f
StandardInput=tty-force
StandardOutput=inherit
StandardError=inherit
TimeoutSec=0

You can look at commits 040f3883 and 5204d1d3 in dracut to see how it is
setup.

> From: "Brian C. Lane"
>
> On Fri, Mar 08, 2013 at 02:55:40PM -0500, [e-mail] wrote:
> > I have a custom dracut module installed as a pre-mount hook (for

Fedora
> > 18).  This shell script needs to echo some messages to the console,

but
> > I'm having no luck making that happen.  I've tried:
>
> This is similar to what we ran into with checkisomd5, now that systemctl
> is being used by dracut you need to setup a service with access to the
> console in order for anything to be output (or input).
>
> The service file for that looks like this:
>
> [Unit]
> Description=Media check on %f
> DefaultDependencies=no
> Before=shutdown.target
>
> [Service]
> Type=oneshot
> RemainAfterExit=no
> ExecStart=/bin/checkisomd5 --verbose %f
> StandardInput=tty-force
> StandardOutput=inherit
> StandardError=inherit
> TimeoutSec=0
>
> You can look at commits 040f3883 and 5204d1d3 in dracut to see how it is
> setup.
>
> -- 
> Brian C. Lane | Anaconda Team | IRC: bcl #anaconda | Port Orchard, 
> WA (PST8PDT)

Thanks for that Brian!  I had pretty much came to that conclusion before 
calling it a day on Friday, but it's very helpful to know that the effort 
to go that route won't be wasted.

--
John Florian

> From: [e-mail]
> > From: "Brian C. Lane"
> >
> > On Fri, Mar 08, 2013 at 02:55:40PM -0500, [e-mail] wrote:
> > > I have a custom dracut module installed as a pre-mount hook (for

Fedora
> > > 18).  This shell script needs to echo some messages to the console,

but
> > > I'm having no luck making that happen.  I've tried:
> >
> > This is similar to what we ran into with checkisomd5, now that

systemctl
> > is being used by dracut you need to setup a service with access to the
> > console in order for anything to be output (or input).
> >
> > The service file for that looks like this:
> >
> > [Unit]
> > Description=Media check on %f
> > DefaultDependencies=no
> > Before=shutdown.target
> >
> > [Service]
> > Type=oneshot
> > RemainAfterExit=no
> > ExecStart=/bin/checkisomd5 --verbose %f
> > StandardInput=tty-force
> > StandardOutput=inherit
> > StandardError=inherit
> > TimeoutSec=0
> >
> > You can look at commits 040f3883 and 5204d1d3 in dracut to see how it

is
> > setup.
> >
> > -- 
> > Brian C. Lane | Anaconda Team | IRC: bcl #anaconda | Port Orchard, 
> > WA (PST8PDT)
>
> Thanks for that Brian!  I had pretty much came to that conclusion 
> before calling it a day on Friday, but it's very helpful to know 
> that the effort to go that route won't be wasted.
>
> --
> John Florian

I just wanted to drop another note and thank you to mention that I got it 
working.  I had been mimicking how the dracut-emergency.service worked, 
but the media-check service made an even better example by being even more 
trivial.  So, thanks again!

--
John Florian

Fwd: Can't echo to console from dracut module

[Jins Nazir]

---------- Forwarded message ----------
From: "Brian C. Lane" 
Date: Mon, 11 Mar 2013 06:37:41 -0700
Subject: Re: [Fedora-livecd-list] Can't echo to console from dracut module
To: [e-mail]

On Fri, Mar 08, 2013 at 02:55:40PM -0500, [e-mail] wrote:
> I have a custom dracut module installed as a pre-mount hook (for Fedora
> 18).  This shell script needs to echo some messages to the console, but
> I'm having no luck making that happen.  I've tried:

This is similar to what we ran into with checkisomd5, now that systemctl
is being used by dracut you need to setup a service with access to the
console in order for anything to be output (or input).

The service file for that looks like this:

[Unit]
Description=Media check on %f
DefaultDependencies=no
Before=shutdown.target

[Service]
Type=oneshot
RemainAfterExit=no
ExecStart=/bin/checkisomd5 --verbose %f
StandardInput=tty-force
StandardOutput=inherit
StandardError=inherit
TimeoutSec=0

You can look at commits 040f3883 and 5204d1d3 in dracut to see how it is
setup.