cups-service v2

[Danny Milosavljevic <dannym@scratchpost.org>]

I think I have most of the parts now. Not sure how to tie them together, though:

diff --git a/gnu/services/printing.scm b/gnu/services/printing.scm
new file mode 100644
index 0000000..d8f6924
--- /dev/null
+++ b/gnu/services/printing.scm
@@ -0,0 +1,147 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
+;;;
+;;; 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 printing)
+  #:use-module (gnu services)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu packages cups)
+  #:use-module (guix gexp)
+  #:use-module (guix records)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-9)
+  #:use-module (srfi srfi-26)
+  #:use-module (ice-9 match)
+  #:export (cups-service))
+
+(define (default-cups-files-config data-dir)
+  ;; generate cups-files.conf [for cupsd -s ...], especially dynamically set DataDir.
+  (mixed-text-file "cups-files.conf"
+                   "AccessLog syslog\n"
+                   "ErrorLog syslog\n"
+                   "PageLog syslog\n"
+                   "FatalErrors all\n"
+                   "SyncOnClose Yes\n"
+                   "User nobody\n"
+                   "Group lp\n"
+                   ; FIXME SystemGroup lpadmin sys system root
+                   ; FIXME ConfigFilePerm
+                   ;; DataDir /var/lib/cupsd/data
+                   (string-append "DataDir " data-dir "\n") ; /gnu/store/1h53jmsx7gm7b2sfk0h0k6bgmp8fhv0i-cups-2.1.0/share/cups
+                   (string-append "DocumentRoot " /gnu/store/1h53jmsx7gm7b2sfk0h0k6bgmp8fhv0i-cups-2.1.0 "/share/doc/cups\n")
+                   "CacheDir /var/cache/cups\n"
+                   "StateDir /var/run/cups\n"
+                   ; FIXME FontPath /zzz
+                   "Printcap /etc/printcap\n"
+                   "PrintcapFormat bsd\n"
+                   "RequestRoot /var/spool/cups\n"
+                   ;;/gnu/store/1h53jmsx7gm7b2sfk0h0k6bgmp8fhv0i-cups-2.1.0/lib/cups
+                   "ServerBin /home/dannym/.guix-profile/lib/cups\n" ; FIXME
+                   "ServerRoot /etc/cups\n" ; FIXME
+))
+
+;; TODO same with /usr/lib/cups
+(define (data-directory packages)
+  "Return a directory containing
+     @file{banners}
+     @file{charsets}
+     @file{drv} (most important)
+     @file{fonts}
+     @file{ipptool}
+     @file{locale}
+     @file{mime}
+     @file{model} (empty)
+     @file{ppdc}
+     @file{ppd-updaters}
+     @file{profiles} (empty)
+     @file{templates}
+     @file{usb}
+   merged from the packages
+  "
+  (computed-file "usr-share-cups"
+    #~(begin
+        (use-modules (guix build union) (srfi srfi-26))
+        (union-build #$output
+                     (map (cut string-append <> "/share/cups")
+                          (list #$@packages))))
+    #:modules '((guix build union))))
+
+(define-record-type* <cups-configuration>
+  cups-configuration make-cups-configuration
+  cups-configuration?
+  (printers cups-configuration-printers)
+  (provision cups-configuration-provision)
+  (cups cups-configuration-cups (default cups))
+  (actions cups-configuration-actions (default '()))) ; package list
+
+; TODO cupsd -c /etc/cupsd.conf -F
+; TODO what user should cupsd run as? (Debian: root)
+; TODO cups-browsed (Debian: also as root)
+; TODO list of printers; paper size, printer vendor and model, interface (if necessary).
+; TODO binding to network interface; running the config html page; auth there; auth in general?
+; TODO support scanners and hpaio thing as sane dll
+
+; 
+; 
+; 
+; merge: /var/lib/hp ? no
+; merge: /etc/hp ? no
+; merge: /usr/share/hal/fdi ? useless.
+; merge: /etc/udev/rules.d ? done.
+; merge: /lib/systemd/system ? useless.
+; merge: /lib/cups/filter
+; merge: /lib/cups/backend
+; merge: mime.types
+; merge: /share/applications
+; merge: /usr/share/ppd/HP via DRV into DataDir.
+; merge: drv into DataDir
+
+(define cups-shepherd-service
+   (match-lambda
+     (($ <cups-configuration> printers provision cups)
+      (let ((loopback? (memq 'loopback provision)))
+       (list
+        (shepherd-service
+         (requirement '(udev networking)) ; TODO check actual config and reduce
+         (documentation "Bring up printing services.")
+         (provision provision)
+         (start #~(make-forkexec-constructor
+                   (list (string-append #$cups "/sbin/cupsd")
+                         "-s" (default-cups-files-config "/tmp") ; FIXME merged datadir
+                         ; FIXME "-c" cups config
+                         "-f")))
+         (stop #~(make-kill-destructor))))))))
+
+(define cups-service-type
+  (service-type (name 'cups)
+                (extensions
+                 (list (service-extension shepherd-root-service-type cups-shepherd-service)))
+                (compose concatenate)
+                (extend (lambda (config actions)
+                          (cups-configuration
+                           (inherit config)
+                           (actions
+                            (append (cups-configuration-actions config)
+                                    actions)))))))
+
+(define* (cups-service #:key printers (provision '(printing)) )
+  "Return a printing service that starts cups."
+  (service cups-service-type
+           (cups-configuration (printers printers)
+                               (provision provision))))
+