bug#63921: Activation snippets in reverse order, prevent boot

bug#63921: Activation snippets in reverse order, prevent boot

[Ludovic Courtès]

Booting a system reconfigured from
eed55a6544d5bda2245ec853e5fa4b28e1865bea fails with shepherd saying:

  error: while opening socket '/var/run/shepherd/socket': Address already in use

The root cause appears to be that the ‘boot’ program has expressions
reversed:

--8<---------------cut here---------------start------------->8---
$ guix gc --references $(guix gc --derivers $(readlink -f /var/guix/profiles/system-236-link)) | grep boot
/gnu/store/21ldhyrpji6lkkdxi4lgr5k9l5fr2b7l-boot.drv
$ cat $(guix build /gnu/store/21ldhyrpji6lkkdxi4lgr5k9l5fr2b7l-boot.drv)
(eval-when (expand load eval) (let ((extensions (quote ())) (prepend (lambda (items lst) (let loop ((items items) (lst lst)) (if (null? items) lst (loop (cdr items) (cons (car items) (delete (car items) lst)))))))) (set! %load-path (prepend (cons "/gnu/store/pj751v3199vmv6i6sf0szp185ryzcfdg-module-import" (map (lambda (extension) (string-append extension "/share/guile/site/" (effective-version))) extensions)) %load-path)) (set! %load-compiled-path (prepend (cons "/gnu/store/pql80c2hy38bb60c68sng74s4xa35vwk-module-import-compiled" (map (lambda (extension) (string-append extension "/lib/guile/" (effective-version) "/site-ccache")) extensions)) %load-compiled-path))))(begin (begin (false-if-exception (delete-file "/run/booted-system")) (symlink (canonicalize-path "/run/current-system") "/run/booted-system") (let loop ((fd 3)) (when (< fd 1024) (false-if-exception (let ((flags (fcntl fd F_GETFD))) (when (zero? (logand flags FD_CLOEXEC)) (fcntl fd F_SETFD (logior FD_CLOEXEC flags))))) (loop (+ fd 1)))) (execl "/gnu/store/wj5i6x3xgai7p8whwqybxwqdjdbmbzha-shepherd-0.10.99-git/bin/shepherd" "shepherd" "--config" "/gnu/store/gnjghlc3n5qbala5jfdslgfi0n3vy8v7-shepherd.conf")) (primitive-load "/gnu/store/riabgidmf6fh76klc1yam7k9j1478vvw-activate.scm") (begin (use-modules (guix build utils)) (letrec-syntax ((fail-safe (syntax-rules () ((_ exp rest ...) (begin (catch (quote system-error) (lambda () exp) (const #f)) (fail-safe rest ...))) ((_) #t)))) (fail-safe (delete-file "/etc/group.lock") (delete-file "/etc/passwd.lock") (delete-file "/etc/.pwd.lock") (setenv "GUIX_LOCPATH" "/gnu/store/5fmqijrs5f7vx8mc2q2pmq26yvhb74sm-glibc-utf8-locales-2.35/lib/locale") (setlocale LC_CTYPE "en_US.utf8") (delete-file-recursively "/tmp") (delete-file-recursively "/var/run") (mkdir "/tmp") (chmod "/tmp" 1023) (mkdir "/var/run") (chmod "/var/run" 493) (delete-file-recursively "/run/udev/watch.old")))))
--8<---------------cut here---------------end--------------->8---

Namely, (execl "…/bin/shepherd") comes before the cleanup expressions,
which is why /var/run/shepherd/socket is still around when we boot.

Ludo’.

bug#63921: Activation snippets in reverse order, prevent boot

[Ludovic Courtès]

Ludovic Courtès <ludo@gnu.org> skribis:

> Booting a system reconfigured from
> eed55a6544d5bda2245ec853e5fa4b28e1865bea fails with shepherd saying:
>
>   error: while opening socket '/var/run/shepherd/socket': Address already in use
>
> The root cause appears to be that the ‘boot’ program has expressions
> reversed:
>
> $ guix gc --references $(guix gc --derivers $(readlink -f /var/guix/profiles/system-236-link)) | grep boot
> /gnu/store/21ldhyrpji6lkkdxi4lgr5k9l5fr2b7l-boot.drv
> $ cat $(guix build /gnu/store/21ldhyrpji6lkkdxi4lgr5k9l5fr2b7l-boot.drv)
> (eval-when (expand load eval) (let ((extensions (quote ())) (prepend (lambda (items lst) (let loop ((items items) (lst lst)) (if (null? items) lst (loop (cdr items) (cons (car items) (delete (car items) lst)))))))) (set! %load-path (prepend (cons "/gnu/store/pj751v3199vmv6i6sf0szp185ryzcfdg-module-import" (map (lambda (extension) (string-append extension "/share/guile/site/" (effective-version))) extensions)) %load-path)) (set! %load-compiled-path (prepend (cons "/gnu/store/pql80c2hy38bb60c68sng74s4xa35vwk-module-import-compiled" (map (lambda (extension) (string-append extension "/lib/guile/" (effective-version) "/site-ccache")) extensions)) %load-compiled-path))))(begin (begin (false-if-exception (delete-file "/run/booted-system")) (symlink (canonicalize-path "/run/current-system") "/run/booted-system") (let loop ((fd 3)) (when (< fd 1024) (false-if-exception (let ((flags (fcntl fd F_GETFD))) (when (zero? (logand flags FD_CLOEXEC)) (fcntl fd F_SETFD (logior FD_CLOEXEC flags))))) (loop (+ fd 1)))) (execl "/gnu/store/wj5i6x3xgai7p8whwqybxwqdjdbmbzha-shepherd-0.10.99-git/bin/shepherd" "shepherd" "--config" "/gnu/store/gnjghlc3n5qbala5jfdslgfi0n3vy8v7-shepherd.conf")) (primitive-load "/gnu/store/riabgidmf6fh76klc1yam7k9j1478vvw-activate.scm") (begin (use-modules (guix build utils)) (letrec-syntax ((fail-safe (syntax-rules () ((_ exp rest ...) (begin (catch (quote system-error) (lambda () exp) (const #f)) (fail-safe rest ...))) ((_) #t)))) (fail-safe (delete-file "/etc/group.lock") (delete-file "/etc/passwd.lock") (delete-file "/etc/.pwd.lock") (setenv "GUIX_LOCPATH" "/gnu/store/5fmqijrs5f7vx8mc2q2pmq26yvhb74sm-glibc-utf8-locales-2.35/lib/locale") (setlocale LC_CTYPE "en_US.utf8") (delete-file-recursively "/tmp") (delete-file-recursively "/var/run") (mkdir "/tmp") (chmod "/tmp" 1023) (mkdir "/var/run") (chmod "/var/run" 493) (delete-file-recursively "/run/udev/watch.old")))))
>
> Namely, (execl "…/bin/shepherd") comes before the cleanup expressions,
> which is why /var/run/shepherd/socket is still around when we boot.

Fixed in 181951207339508789b28ba7cb914f983319920f.

The regression came from dbbc7e946131ba257728f1d05b96c4339b7ee88b, which
led ‘modify-services’ to change the order of services (something I had
completely overlooked while reviewing, apologies!).  I ended up
rewriting ‘modify-services’.  Good news is we now have tests for this.

Ludo’.

bug#63921: Activation snippets in reverse order, prevent boot

[pelzflorian (Florian Pelz)]

Hi Ludo, hi all.

Ludovic Courtès <ludo@gnu.org> writes:
> I ended up
> rewriting ‘modify-services’.  Good news is we now have tests for this.

In the rewrite, you wrote:
> +(define (apply-clauses clauses services)
> +  "Apply CLAUSES, an alist as returned by 'clause-alist', to SERVICES, a list
> +of services.  Use each clause at most once; raise an error if a clause was not
> +used."

Using clauses at most once broke the greetd example in the manual:
> (append
>  (modify-services %base-services
>    ;; greetd-service-type provides "greetd" PAM service
>    (delete login-service-type)
>    ;; and can be used in place of mingetty-service-type
>    (delete mingetty-service-type))
>  (list
>   (service greetd-service-type

But there are multiple instances of mingetty-service-type in
%base-services.  Now an error is raised on reconfigure because there are
two term-tty2 services.

I’m not sure, isn’t it more explicit if we keep your change of deleting
at most once, but change the greetd example?

The following works for me now …

(modify-services %base-services
                 (delete login-service-type)
                 (delete mingetty-service-type)
                 (delete mingetty-service-type)
                 (delete mingetty-service-type)
                 (delete mingetty-service-type)
                 (delete mingetty-service-type)
                 (delete mingetty-service-type))

Regards,
Florian

bug#63921: Activation snippets in reverse order, prevent boot

[pelzflorian (Florian Pelz)]

"pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de> writes:
> Using clauses at most once broke the greetd example in the manual:

Jelle Licht already reported this on IRC, see the end of
<http://logs.guix.gnu.org/guix/2023-06-06.log>

Regards,
Florian

bug#63921: Activation snippets in reverse order, prevent boot

[pelzflorian (Florian Pelz)]

"pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de> writes:
> "pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de> writes:
>> Using clauses at most once broke the greetd example in the manual:
> Jelle Licht already reported this on IRC, see the end of
> <http://logs.guix.gnu.org/guix/2023-06-06.log>

Cc Jelle Licht

bug#63921: Activation snippets in reverse order, prevent boot

[Jelle Licht]

"pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de> writes:

> Hi Ludo, hi all.
>
[snip]

> The following works for me now …
>
> (modify-services %base-services
>                  (delete login-service-type)
>                  (delete mingetty-service-type)
>                  (delete mingetty-service-type)
>                  (delete mingetty-service-type)
>                  (delete mingetty-service-type)
>                  (delete mingetty-service-type)
>                  (delete mingetty-service-type))

Thanks for the workaround! Is this "thou shall delete N times, and
_exactly_ N times" effect of the recently pushed change functioning as
intended?  It imho seems pretty brittle and verbose compared to how
things were before.

- Jelle

bug#63921: Activation snippets in reverse order, prevent boot

[Brian Cully via Bug reports for GNU Guix]

Jelle Licht <jlicht@fsfe.org> writes:

> Thanks for the workaround! Is this "thou shall delete N times, 
> and
> _exactly_ N times" effect of the recently pushed change 
> functioning as
> intended?  It imho seems pretty brittle and verbose compared to 
> how
> things were before.

We could add a ‘delete-all’ in addition to the existing ‘delete’ 
behavior. Alternately, we could change ‘delete’ back to deleting 
everything and adding ‘delete-one’. Or have both ‘delete-all’ and 
‘delete-one’ where ‘delete’ is a deprecated alias for ‘delete-all’ 
to add a path forward for older configs.

Of the three I'm most partial to the last, though I love none of 
them. I keep thinking the right solution is to have a delete that 
can match with a predicate, but then why not just use ‘filter’ or 
‘remove’?

-bjc

bug#63921: Activation snippets in reverse order, prevent boot

[pelzflorian (Florian Pelz)]

Jelle is right, multiple (delete mingetty-service-type) is not useful.
With more thought, what I imagined as more explicit is probably more
like (delete "term-tty2") than (delete mingetty-service-type).  Also I
wouldn’t actually need it.

And as Brian says, just use filter.  modify-services need not do more
than what is already documented.

I would be happy if someone else would undo the change to “delete at
most once”.

Regards,
Florian

bug#63921: Activation snippets in reverse order, prevent boot

[pelzflorian (Florian Pelz)]

David Wilson has described a way to fix this bug in Guix
<https://issues.guix.gnu.org/64106>

Regards,
Florian

bug#63921: Patch proposed

[Felix Lechner via Bug reports for GNU Guix]

Hi,

A patch to resolve this issue was proposed at the other bug

  https://issues.guix.gnu.org/64106#5

Kind regards
Felix

bug#63921: Activation snippets in reverse order, prevent boot

[Maxim Cournoyer]

Hello,

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

> Hi,
>
> A patch to resolve this issue was proposed at the other bug
>
>   https://issues.guix.gnu.org/64106#5

Brian's patch in https://issues.guix.gnu.org/64106#7 was installed; it
came with tests and also cause an error to be raised when attempting to
modify a phase already deleted.

Closing, thanks for the reminder.

-- 
Thanks,
Maxim