bug#52976: Some tools in Samba fail to find modules, and a missing dependency

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hello Simon,

Simon Streit <simon@netpanic.org> writes:

> While experimenting with Samba, I noticed that some tools, especially
> samba-tools will not run, and crash:
>
> root@motor ~# samba-tool
> Traceback (most recent call last):
>   File "/run/current-system/profile/bin/samba-tool", line 33, in <module>
>     from samba.netcmd.main import cmd_sambatool
>   File "/gnu/store/78baaab8085rd5xnfrpdkxdf07zkmin9-samba-mod-4.13.14/lib/python3.9/site-packages/samba/__init__.py", line 29, in <module>
>     import samba.param
> ModuleNotFoundError: No module named 'talloc'
>
> Doing more testing, other tools appear to not find the libraries they
> need too.  The combination is as folows:
>  - samba-tool, fails when tdb missing.
>  - samba-gpupdate Idem.
>  - samba_dnsupdate requires dnspython, but fails when talloc missing.
>  - samba_downgrade_db" fails when tdb missing.
>  - samba_kcc Idem.
>  - samba_spnupdate" Idem.
>  - samba_upgradedns" dns not found when talloc missing.
>
> I prepared a small patch to wrap up the inputs appropriately.  I hope it
> is acceptable that they are all combined in one wrap procedure.

Thanks for testing samba!

I've updated samba recently on the version-1.4.0 branch; but the problem
probably remains (I've only tested smbd and smbclient).  It's now at
version 4.15.3 and I nedded to add the python-cryptogaphy,
python-dnspython, python-markdown and python-pyasn1 as native inputs.
Based on your findings it probably should be moved to an input.

>>From 201dc8e01fa4484e24b3e088ab6a4211e9839f33 Mon Sep 17 00:00:00 2001
> From: Simon Streit <simon@netpanic.org>
> Date: Mon, 3 Jan 2022 13:08:23 +0100
> Subject: [PATCH] gnu: samba: Use PYTHONPATH.
>
> * gnu/packages/samba.scm (samba): Use PYTHONPATH in 'wrap-program phase..
> ---
>  gnu/packages/samba.scm | 28 ++++++++++++++++++++++++++--
>  1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/gnu/packages/samba.scm b/gnu/packages/samba.scm
> index bb5b402eee..33a39eb3be 100644
> --- a/gnu/packages/samba.scm
> +++ b/gnu/packages/samba.scm
> @@ -235,7 +235,30 @@ (define-public samba
>             (lambda _
>               (substitute* "dynconfig/wscript"
>                 (("bld\\.INSTALL_DIR.*") ""))
> -             #t)))
> +             #t))

Trailing #t are no longer needed.

> +         (add-after 'install 'wrap-program
> +           ;; Some samba tools selectively fail to find talloc, tdb
> +           ;; and dnspython.
> +           (lambda* (#:key inputs outputs #:allow-other-keys)
> +             (let ((out (string-append (assoc-ref outputs "out")))
> +                   (talloc (string-append (assoc-ref inputs "talloc")
> +                                          "/lib/python3.9/site-packages"))
> +                   (tdb (string-append (assoc-ref inputs "tdb")
> +                                       "/lib/python3.9/site-packages"))
> +                   (python-dnspython (string-append
> +                                      (assoc-ref inputs "python-dnspython")
> +                                      "/lib/python3.9/site-packages")))

We shouldn't hard code Python versions in the paths as it'd be too prone
to break.  You could probably make good use of the recently introduced
search-input-directory procedure here :-).

> +               (for-each
> +                (lambda (bin)
> +                  (wrap-program (string-append out bin)
> +                    `("PYTHONPATH" prefix (,talloc ,tdb ,python-dnspython))))

Make sure to run 'guix lint', it'll probably suggest to add minimal-bash
as an input because of the use of wrap-program.

> +                '("/bin/samba-tool"
> +                  "/sbin/samba-gpupdate"
> +                  "/sbin/samba_dnsupdate"
> +                  "/sbin/samba_downgrade_db"
> +                  "/sbin/samba_kcc"
> +                  "/sbin/samba_spnupdate"
> +                  "/sbin/samba_upgradedns"))))))
>         ;; FIXME: The test suite seemingly hangs after failing to provision the
>         ;; test environment.
>         #:tests? #f))
> @@ -258,7 +281,8 @@ (define-public samba
>             python
>             popt
>             readline
> -           tdb))
> +           tdb
> +           python-dnspython))
>      (propagated-inputs
>       ;; In Requires or Requires.private of pkg-config files.
>       (list ldb talloc tevent))

Otherwise it LGTM.  Could you try to rebase this patch on top of the
version-1.4.0 branch?  Otherwise, wait a few days and it should be
merged into master.

Thank you!

Maxim