Mcron jobs using with-mail-out

Mcron jobs using with-mail-out

[Felix Lechner via]

Hi,

Does anyone have a working job specification for Mcron that uses
"with-mail-out"? [1] I have some trouble providing (mcron redirect)
inside the gexp. Thanks!

Kind regards
Felix

[1] https://www.gnu.org/software/mcron/manual/mcron.html#index-with_002dmail_002dout

Re: Mcron jobs using with-mail-out

[Maxim Cournoyer]

Hi Felix,

Felix Lechner via <help-guix@gnu.org> writes:

> Hi,
>
> Does anyone have a working job specification for Mcron that uses
> "with-mail-out"? [1] I have some trouble providing (mcron redirect)
> inside the gexp. Thanks!

Sorry, I don't, but I'd be interested in a concrete example as well.

-- 
Thanks,
Maxim

Re: Mcron jobs using with-mail-out

[Simon Streit]

Hello,

Maxim Cournoyer <maxim.cournoyer@gmail.com> writes:
>
> Felix Lechner via <help-guix@gnu.org> writes:
>>
>> Does anyone have a working job specification for Mcron that uses
>> "with-mail-out"? [1] I have some trouble providing (mcron redirect)
>> inside the gexp. Thanks!
>
> Sorry, I don't, but I'd be interested in a concrete example as well.

I figured out a procedure for my home environment:

--8<---------------cut here---------------start------------->8---
(use-modules (gnu packages guile-xyz))  ;to load mcron redirect

#~(job
   '(next-minute)
   #$(program-file
      "ls.scm"
      #~(begin
          (use-modules (mcron redirect))
          (setenv "PATH" (string-append (getenv "PATH")
                                        ":/run/setuid-programs/"))
          (with-mail-out (lambda ()
                           (system (string-append #$coreutils
                                                  "/bin/ls")))
                         "user@localhost"))))
--8<---------------cut here---------------end--------------->8---

It looks a slightly different when applying this job to a system wide
declaration:

--8<---------------cut here---------------start------------->8---
(use-modules (gnu packages guile-xyz))  ;to load mcron redirect

#~(job
   '(next-minute)
   #$(program-file
      "ls.scm"
      (with-extensions
          (list mcron)
        #~(begin
            (use-modules (mcron redirect))
            (setenv "PATH"
                    (string-append (getenv "PATH")
                                   ":/run/setuid-programs/"))
            (with-mail-out (lambda ()
                             (system (string-append #$coreutils
                                                    "/bin/ls"))))))))
--8<---------------cut here---------------end--------------->8---

The action has to have its PATH extended, otherwise it fails to find
sendmail.  With this I have mcron sending mail to me.

The documentation of mcron does not state that the user name is optional.


Have a nice day,

-- 
Simon

Re: Mcron jobs using with-mail-out

[Felix Lechner via]

Hi Simon,

On Mon, Aug 05 2024, Simon Streit wrote:

> (setenv "PATH"
>         (string-append (getenv "PATH")
>                        ":/run/setuid-programs/"))

Thanks for that!

Do you provide a 'sendmail' executable in your system profile?  If so,
should the system PATH include "/run/setuid-programs"?

Kind regards
Felix

Re: Mcron jobs using with-mail-out

[Simon Streit]

Hi Felix,

Felix Lechner <felix.lechner@lease-up.com> writes:

> Do you provide a 'sendmail' executable in your system profile?  If so,
> should the system PATH include "/run/setuid-programs"?

I haven OpenSMTPd running as a service and have provided the packet
through the system profile. But /run/setuid-programs is not available
for mcron.  Should it be?  And if, how can I change that?


Kind regards,

-- 
Simon

Re: Mcron jobs using with-mail-out

[Simon Streit]

Felix Lechner <felix.lechner@lease-up.com> writes:

> Do you provide a 'sendmail' executable in your system profile?  If so,
> should the system PATH include "/run/setuid-programs"?

I understand your question now.  Please disregard my previous message.
Sendmail is available through /run/current-system/profile/sbin and
/run/setuid-programs/sendmail.  Both are provided by OpenSMTPd.  I don't
have sendmail in my user profile, and am trying to get on with mailutils
and OpenSMTPd only for the time being.  I have no need for msmtpd yet.

Mcron's service PATH contains only /run/current-system/profile/bin and
thus can't find sendmail.

If I use my previous job example and leave (setenv ...) out, I get the
following error:

--8<---------------cut here---------------start------------->8---
2024-08-08 12:17:00 19819 /gnu/store/ir80y6y5g4w1qf2fcqm71lv8rh2gppwq-setuid-sans.scm: running...
2024-08-08 12:17:00 19819 /gnu/store/ir80y6y5g4w1qf2fcqm71lv8rh2gppwq-setuid-sans.scm: completed in 0.090s
2024-08-08 12:17:00 19819 /gnu/store/ir80y6y5g4w1qf2fcqm71lv8rh2gppwq-setuid-sans.scm: /gnu/store/fl3l5wx8qynjrvx5lilz6c38hb77cf36-bash-minimal-5.1.16/bin/bash: line 1: sendmail: command not found
--8<---------------cut here---------------end--------------->8---

This is slowly giving me a slight headache.  Should mcron not know
about sbin, and maybe more so about setuid binaries?

The PATH in gnu/services/mcron.scm is defined a follows:

--8<---------------cut here---------------start------------->8---
#:environment-variables
(cons* "GUILE_AUTO_COMPILE=0"
       "PATH=/run/current-system/profile/bin"
       (remove (cut string-prefix? "PATH=" <>)
               (environ)))
--8<---------------cut here---------------end--------------->8---

This applies generally.  Is that not too limiting?


Kind regards

-- 
Simon