native-search-paths and shepherd services (help wanted)

native-search-paths and shepherd services (help wanted)

[Jonathan Frederickson]

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Hi - I'm working on a Guix service for Minetest, and I'm running into some issues. The Guix package for Minetest is divided into two variables: "minetest" and "minetest-data", with only the former being an installable package. The Minetest package uses native-search-paths to allow Minetest to find additional available games (MINETEST_SUBGAME_PATH), *including* minetest_game which is effectively the default.

This is all well and good when you're installing Minetest as a package and running it manually, but I'd like to do this with a Guix service instead. Problem is... the native-search-paths don't seem to affect the environment variables set when I run Minetest through Shepherd. I'm checking my env vars by running Minetest through strace in the shepherd service at the moment:

      (start #~(make-forkexec-constructor
                (list #$(file-append strace "/bin/strace") "-s1024" "-vfe" "trace=execve" #$(file-append package "/bin/minetest")
                      "--server" "testworld"
                      "--map-dir" #$map-dir)
                #:user "minetest"
                #:group "minetest"))

(I've attached my current services/games.scm for reference.)

Is there a way for me to use the native-search-paths from the installed Minetest package when starting it through Shepherd?

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[-- Attachment #2: games.scm --]
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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018 Arun Isaac <arunisaac@systemreboot.net>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu services games)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages linux) ;; for strace - remove this
  #:use-module (gnu packages games)
  #:use-module (gnu system shadow)
  #:use-module (guix gexp)
  #:use-module (guix modules)
  #:use-module (guix records)
  #:use-module (ice-9 match)
  #:export (wesnothd-configuration
            wesnothd-configuration?
            wesnothd-service-type
            minetest-configuration
            minetest-configuration?
            minetest-service-type))

;;;
;;; The Battle for Wesnoth server
;;;

(define-record-type* <wesnothd-configuration>
  wesnothd-configuration make-wesnothd-configuration wesnothd-configuration?
  (package wesnothd-configuration-package
           (default wesnoth-server))
  (port wesnothd-configuration-port
        (default 15000)))

(define %wesnothd-accounts
  (list
   (user-account
    (name "wesnothd")
    (group "wesnothd")
    (system? #t)
    (comment "Wesnoth daemon user")
    (home-directory "/var/empty")
    (shell
     (file-append shadow "/sbin/nologin")))
   (user-group
    (name "wesnothd")
    (system? #t))))

(define wesnothd-shepherd-service
  (match-lambda
    (($ <wesnothd-configuration> package port)
     (with-imported-modules
         (source-module-closure
          '((gnu build shepherd)))
       (shepherd-service
        (documentation "The Battle for Wesnoth server")
        (provision
         '(wesnoth-daemon))
        (requirement
         '(networking))
        (modules
         '((gnu build shepherd)))
        (start #~(make-forkexec-constructor/container
                  (list #$(file-append package "/bin/wesnothd")
                        "-p" #$(number->string port))
                  #:user "wesnothd" #:group "wesnothd"))
        (stop #~(make-kill-destructor)))))))

(define wesnothd-service-type
  (service-type
   (name 'wesnothd)
   (description
    "Run The Battle for Wesnoth server @command{wesnothd}.")
   (extensions
    (list
     (service-extension account-service-type
                        (const %wesnothd-accounts))
     (service-extension shepherd-root-service-type
                        (compose list wesnothd-shepherd-service))))
   (default-value
     (wesnothd-configuration))))

(define-record-type* <minetest-configuration>
  minetest-configuration make-minetest-configuration minetest-configuration?
  (package minetest-configuration-package
           (default minetest))
  (config-file minetest-config-file
               (default "/etc/minetest.conf"))
  (map-dir minetest-map-dir
           (default "/tmp")))

(define %minetest-accounts
  (list
   (user-account
    (name "minetest")
    (group "minetest")
    (system? #t)
    (comment "Minetest daemon user")
    (home-directory "/var/minetest")
    (shell
     (file-append shadow "/sbin/nologin")))
   (user-group
    (name "minetest")
    (system? #t))))

(define minetest-shepherd-service
  (match-lambda
    (($ <minetest-configuration> package port map-dir)
     (shepherd-service
      (documentation "Minetest server.")
      (requirement '(networking))
      (provision '(minetest))
      (start #~(make-forkexec-constructor
                ;;(list #$(file-append package "/bin/minetest")
                ;;      "--server" "testworld"
                ;;      "--map-dir" #$map-dir)
                (list #$(file-append strace "/bin/strace") "-s1024" "-vfe" "trace=execve" #$(file-append package "/bin/minetest")
                      "--server" "testworld"
                      "--map-dir" #$map-dir)
                #:user "minetest"
                #:group "minetest"))
                ;;#:environment-variables
                ;;'("HOME=/var/minetest")))
      (stop #~(make-kill-destructor))))))

(define minetest-service-type
  (service-type
   (name 'minetest)
   (description
    "Run the Minetest server @command{minetest}.")
   (extensions
    (list (service-extension account-service-type
                             (const %minetest-accounts))
          (service-extension profile-service-type
                             (lambda (config)
                               (list (minetest-configuration-package
                                      config))))
          (service-extension shepherd-root-service-type
                             (compose list minetest-shepherd-service))))
   (default-value (minetest-configuration))))

Re: native-search-paths and shepherd services (help wanted)

[Brice Waegeneire]

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On 2020-02-08 09:06, Jonathan Frederickson wrote:
> Hi - I'm working on a Guix service for Minetest, and I'm running into
> some issues. The Guix package for Minetest is divided into two
> variables: "minetest" and "minetest-data", with only the former being
> an installable package. The Minetest package uses native-search-paths
> to allow Minetest to find additional available games
> (MINETEST_SUBGAME_PATH), *including* minetest_game which is
> effectively the default.
> 
> This is all well and good when you're installing Minetest as a package
> and running it manually, but I'd like to do this with a Guix service
> instead. Problem is... the native-search-paths don't seem to affect
> the environment variables set when I run Minetest through Shepherd.
> I'm checking my env vars by running Minetest through strace in the
> shepherd service at the moment:
> 
>       (start #~(make-forkexec-constructor
>                 (list #$(file-append strace "/bin/strace") "-s1024"
> "-vfe" "trace=execve" #$(file-append package "/bin/minetest")
>                       "--server" "testworld"
>                       "--map-dir" #$map-dir)
>                 #:user "minetest"
>                 #:group "minetest"))
> 
> (I've attached my current services/games.scm for reference.)
> 
> Is there a way for me to use the native-search-paths from the
> installed Minetest package when starting it through Shepherd?

I think I got it working, I managed to log and "play" on the server.

You were really close to have a working service for minetest though. You 
were only missing the environment variable MINETEST_SUBGAME_PATH and 
*maybe* your profile-service-type extension was wrong (I just blandly 
copied how it was done for SDDM). I have attached your games.scm with 
the added fixes.

[-- Attachment #2: games.scm --]
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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018 Arun Isaac <arunisaac@systemreboot.net>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu services games)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages linux) ;; for strace - remove this
  #:use-module (gnu packages games)
  #:use-module (gnu system shadow)
  #:use-module (guix gexp)
  #:use-module (guix modules)
  #:use-module (guix records)
  #:use-module (ice-9 match)
  #:export (wesnothd-configuration
            wesnothd-configuration?
            wesnothd-service-type
            minetest-configuration
            minetest-configuration?
            minetest-service-type))

;;;
;;; The Battle for Wesnoth server
;;;

(define-record-type* <wesnothd-configuration>
  wesnothd-configuration make-wesnothd-configuration wesnothd-configuration?
  (package wesnothd-configuration-package
           (default wesnoth-server))
  (port wesnothd-configuration-port
        (default 15000)))

(define %wesnothd-accounts
  (list
   (user-account
    (name "wesnothd")
    (group "wesnothd")
    (system? #t)
    (comment "Wesnoth daemon user")
    (home-directory "/var/empty")
    (shell
     (file-append shadow "/sbin/nologin")))
   (user-group
    (name "wesnothd")
    (system? #t))))

(define wesnothd-shepherd-service
  (match-lambda
    (($ <wesnothd-configuration> package port)
     (with-imported-modules
         (source-module-closure
          '((gnu build shepherd)))
       (shepherd-service
        (documentation "The Battle for Wesnoth server")
        (provision
         '(wesnoth-daemon))
        (requirement
         '(networking))
        (modules
         '((gnu build shepherd)))
        (start #~(make-forkexec-constructor/container
                  (list #$(file-append package "/bin/wesnothd")
                        "-p" #$(number->string port))
                  #:user "wesnothd" #:group "wesnothd"))
        (stop #~(make-kill-destructor)))))))

(define wesnothd-service-type
  (service-type
   (name 'wesnothd)
   (description
    "Run The Battle for Wesnoth server @command{wesnothd}.")
   (extensions
    (list
     (service-extension account-service-type
                        (const %wesnothd-accounts))
     (service-extension shepherd-root-service-type
                        (compose list wesnothd-shepherd-service))))
   (default-value
     (wesnothd-configuration))))

(define-record-type* <minetest-configuration>
  minetest-configuration make-minetest-configuration minetest-configuration?
  (package minetest-configuration-package
           (default minetest))
  (config-file minetest-config-file
               (default "/etc/minetest.conf"))
  (map-dir minetest-map-dir
           (default "/tmp")))

(define %minetest-accounts
  (list
   (user-account
    (name "minetest")
    (group "minetest")
    (system? #t)
    (comment "Minetest daemon user")
    (home-directory "/var/minetest")
    (shell
     (file-append shadow "/sbin/nologin")))
   (user-group
    (name "minetest")
    (system? #t))))

(define minetest-shepherd-service
  (match-lambda
    (($ <minetest-configuration> package port map-dir)
     (shepherd-service
      (documentation "Minetest server.")
      (requirement '(networking))
      (provision '(minetest))
      (start #~(make-forkexec-constructor
                (list #$(file-append package "/bin/minetest")
                     "--server" "testworld"
                     "--map-dir" #$map-dir)
                ;; (list #$(file-append strace "/bin/strace") "-s1024" "-vfe" "trace=execve" #$(file-append package "/bin/minetest")
                ;;       "--server" "testworld"
                ;;       "--map-dir" #$map-dir)
                #:user "minetest"
                #:group "minetest";; ))
                #:environment-variables
                '("HOME=/var/minetest"
                  "MINETEST_SUBGAME_PATH=/run/current-system/profile/share/minetest/games")))
      (stop #~(make-kill-destructor))))))

(define minetest-profile-service
  (compose list minetest-configuration-package))

(define minetest-service-type
  (service-type
   (name 'minetest)
   (description
    "Run the Minetest server @command{minetest}.")
   (extensions
    (list (service-extension account-service-type
                             (const %minetest-accounts))
          (service-extension profile-service-type
                             minetest-profile-service
                             ;; (lambda (config)
                             ;;   (list (minetest-configuration-package
                             ;;          config)))
                             )
          (service-extension shepherd-root-service-type
                             (compose list minetest-shepherd-service))))
   (default-value (minetest-configuration))))

Re: native-search-paths and shepherd services (help wanted)

[Jonathan Frederickson]

On Sat, Feb 8, 2020, at 10:28 AM, Brice Waegeneire wrote:
> I think I got it working, I managed to log and "play" on the server.
> 
> You were really close to have a working service for minetest though. You 
> were only missing the environment variable MINETEST_SUBGAME_PATH and 
> *maybe* your profile-service-type extension was wrong (I just blandly 
> copied how it was done for SDDM). I have attached your games.scm with 
> the added fixes.

Aha, thank you very much! I didn't know where the profile path was for the current system, so that was very helpful.

I'm still not quite sure I have a good understanding of when 'native-search-paths' applies and when it doesn't, but... at least setting the env var directly seems to work in this case.

Re: native-search-paths and shepherd services (help wanted)

[Brice Waegeneire]

On 2020-02-08 19:10, Jonathan Frederickson wrote:
> I'm still not quite sure I have a good understanding of when
> 'native-search-paths' applies and when it doesn't, but... at least
> setting the env var directly seems to work in this case.

I just learned about native-search-paths when looking into your issue so 
I may be off about how it works...
What I understand is that native-search-paths add an entry to your 
/etc/profile when installed - for your default user profile it's 
$HOME/.guix-profile/etc/profile. In our case, when installed, minetest 
sets the environment variable MINETEST_SUBGAME_PATH so the binary know 
where to looks for the games. But when called directly, as it's the case 
in a shepherd service, the /etc/profile file isn't sourced so the 
environment variable isn't set. That's why we need to set it manually in 
the service.

Re: native-search-paths and shepherd services (help wanted)

[Ludovic Courtès]

Hello,

Brice Waegeneire <brice@waegenei.re> skribis:

> On 2020-02-08 19:10, Jonathan Frederickson wrote:
>> I'm still not quite sure I have a good understanding of when
>> 'native-search-paths' applies and when it doesn't, but... at least
>> setting the env var directly seems to work in this case.
>
> I just learned about native-search-paths when looking into your issue
> so I may be off about how it works...
> What I understand is that native-search-paths add an entry to your
> /etc/profile when installed - for your default user profile it's
> $HOME/.guix-profile/etc/profile. In our case, when installed, minetest
> sets the environment variable MINETEST_SUBGAME_PATH so the binary know
> where to looks for the games. But when called directly, as it's the
> case in a shepherd service, the /etc/profile file isn't sourced so the
> environment variable isn't set. That's why we need to set it manually
> in the service.

Search paths are only used when building a profile, which is not the
case here.

I suppose you’d have to explicitly pass #:environment-variables to
‘make-forkexec-constructor’ to get the desired effect.

HTH,
Ludo’.