services: Introduce extensible services.

This patch rewrites GuixSD services to make them extensible.

* gnu-system.am (GNU_SYSTEM_MODULES): Add gnu/services/dbus.scm.
* gnu/services.scm (<service>): Replace with new record type.
  (<service-extension>, <service-type>): New record types.
  (write-service-type, compute-boot-script, second-argument): New
  procedures.
  (%boot-service, boot-service-type): New variables.
  (file-union, directory-union, modprobe-wrapper,
  activation-service->script, activation-script,
  gexps->activation-gexp): New procedures.
  (activation-service-type, %activation-service): New variables.
  (etc-directory, files->etc-directory, etc-service): New procedures.
  (etc-service-type, setuid-program-service, firmware-service-type): New
  variables.
  (firmware->activation-gexp): New procedure.
  (&service-error, &missing-target-service-error,
  &ambiguous-target-service-error): New condition types.
  (service-back-edges, fold-services): New procedures.
* gnu/services/avahi.scm (<avahi-configuration>): New record type.
  (configuration-file): Replace keyword parameters with a single
  'config' parameter.
  (%avahi-accounts, %avahi-activation, avahi-service-type): New
  variables.
  (avahi-dmd-service): New procedure.
  (avahi-service): Rewrite using 'service' and 'avahi-configuration'.
* gnu/services/base.scm (%root-file-system-dmd-service,
  root-file-system-service-type): New variables.
  (root-file-system-service): Use them.
  (file-system->dmd-service-name): New procedure.
  (file-system-service-type): New variable.
  (file-system-service): Use it.  Replace keyword parameters with a
  single 'file-system' object.
  (user-unmount-service-type): New variable.
  (user-unmount-service): Use it.
  (user-processes-service-type): New variable.
  (user-processes-service): Use it.
  (host-name-service-type): New variable.
  (host-name-service): Use it.
  (console-keymap-service-type): New variable.
  (console-keymap-service): Use it.
  (console-font-service-type): New variable.
  (console-font-service): Use it.
  (mingetty-pam-service, mingetty-dmd-service): New procedures.
  (mingetty-service-type): New variable.
  (mingetty-service): Use it.
  (nscd-dmd-service): New procedure.
  (nscd-activation, nscd-service-type): New variables.
  (nscd-service): Use the latter.
  (syslog-service-type): New variable.
  (syslog-service): Use it.
  (<guix-configuration>): New record type.
  (%default-guix-configuration): New variable.
  (guix-dmd-service, guix-accounts, guix-activation): New procedures.
  (guix-service-type): New variable.
  (guix-service): Replace list of keyword parameters with a single
  'config' parameter.  Rewrite using 'service'.
  (<udev-configuration>): New record type.
  (udev-dmd-service): New procedure.
  (udev-service-type): New variable.
  (udev-service): Use it.
  (device-mapping-service-type): New variable.
  (device-mapping-service): Use it.
  (swap-service-type): New variable.
  (swap-service): Use it.
* gnu/services/databases.scm (<postgresql-configuration>): New record
  type.
  (%postgresql-accounts, postgresql-activation): New variables.
  (postgresql-dmd-service): New procedure.
  (postgresql-service): Rewrite using 'service' and
  'postgresql-configuration'.
* gnu/services/dbus.scm: New file.
* gnu/services/desktop.scm (dbus-configuration-directory, dbus-service):
  Remove.
  (wrapped-dbus-service): New procedure.
  (<upower-configuration>): New record type.
  (upower-configuration-file): Replace keyword parameters with single
  <upower-configuration> parameter.
  (%upower-accounts, %upower-activation): New variables.
  (upower-dbus-service, upower-dmd-service): New procedures.
  (upower-service-type): New variable.
  (upower-service): Rewrite using 'service' and 'upower-configuration'.
  (%colord-activation, %colord-accounts): New variables.
  (colord-dmd-service): New procedure.
  (colord-service-type): New variable.
  (colord-service): Rewrite using 'service'.
  (<geoclue-configuration>): New record type.
  (geoclue-configuration-file): Replace keyword parameters with a single
  'config' parameter.
  (geoclue-dbus-service, geoclue-dmd-service): New procedures.
  (%geoclue-accounts, geoclue-service-type): New variables.
  (geoclue-service): Rewrite using 'service' and
  'geoclue-configuration'.
  (%polkit-accounts, %polkit-pam-services, polkit-service-type): New
  variables.
  (polkit-dmd-service): New procedure.
  (polkit-service): Rewrite using 'service'.
  (<elogind-configuration>)[elogind]: New field.
  (elogind-dmd-service): New procedure.
  (elogind-service-type): New variable.
  (elogind-service): Rewrite using 'service'.
  (%desktop-services): Remove argument to 'dbus-service'.  Remove 'map'
  over %BASE-SERVICES.
* gnu/services/dmd.scm (dmd-boot-gexp): New procedure.
  (dmd-root-service-type, %dmd-root-service): New variables.
  (dmd-service-type): New macro.
  (<dmd-service>): New record type.
* gnu/services/lirc.scm (<lirc-configuration>): New record type.
  (%lirc-activation): New variable.
  (lirc-dmd-service): New procedure.
  (lirc-service-type): New variable.
  (lirc-service): Rewrite using 'service' and 'lirc-configuration'.
* gnu/services/networking.scm (<static-networking>): New record type.
  (static-networking-service-type): New variable.
  (static-networking-service): Rewrite using 'service' and
  'static-networking'.
  (dhcp-client-service-type): New variable.
  (dhcp-client-service): Rewrite using 'service'.
  (<ntp-configuration>): New record type.
  (ntp-dmd-service): New procedure.
  (ntp-service-type): New variable.
  (ntp-service): New procedure.
  (%tor-accounts, tor-service-type): New variable.
  (tor-dmd-service): New procedure.
  (tor-service): Rewrite using 'service'.
  (<bitlbee-configuration>): New record type.
  (bitlbee-dmd-service): New procedure.
  (%bitlbee-accounts, %bitlbee-activation, bitlbee-service-type): New
  variables.
  (bitlbee-service): Rewrite using 'service'.
  (%wicd-activation): New variable.
  (wicd-dmd-service): New procedure.
  (wicd-service-type): New variable.
  (wicd-service): Rewrite using 'service'.
* gnu/services/ssh.scm (<lsh-configuration>): New record type.
  (activation): Rename to...
  (lsh-initialization): ... this.
  (lsh-activation, lsh-dmd-service, lsh-pam-services): New procedures.
  (lsh-service-type): New variable.
  (lsh-service): Rewrite using 'service' and 'lsh-configuration'.
* gnu/services/web.scm (<nginx-configuration>): New record type.
  (%nginx-accounts): New variable.
  (nginx-activation, nginx-dmd-service): New procedures.
  (nginx-service-type): New variable.
  (nginx-service): Rewrite using 'service' and 'nginx-configuration'.
* gnu/services/xorg.scm (<slim-configuration>): New record type.
  (slim-pam-service, slim-dmd-service): New procedures.
  (slim-service-type): New variable.
  (slim-service): Rewrite using 'service' and 'slim-configuration'.
* gnu/system.scm (file-union): Remove.
  (other-file-system-services): Adjust to new 'file-system-service'
  signature.
  (essential-services): Add #:container? parameter.  Add
  %DMD-ROOT-SERVICE, %ACTIVATION-SERVICE, and calls to
  'pam-root-service', 'account-service', 'operating-system-etc-service',
  and a SETUID-PROGRAM-SERVICE instance.
  (operating-system-services): Pass #:container? to 'essential-services.
  (etc-directory): Remove.
  (operating-system-etc-service): New procedure.  Rewrite as a call to
  'etc-service'.
  (operating-system-accounts): Change to not return accounts required by
  services.
  (operating-system-etc-directory): Rewrite as a call to 'fold-services'
  and 'etc-directory'.
  (user-group->gexp, user-account->gexp, modprobe-wrapper): Remove.
  (operating-system-activation-script): Rewrite as a call to
  'fold-services' and 'activation-service->script'.
  (operating-system-boot-script): Likewise.
  (operating-system-derivation): Add call to 'lower-object'.
  (emacs-site-file, emacs-site-directory, shells-file): Change to use
  'computed-file' and 'scheme-file' instead of the monadic procedures.
* gnu/system/install.scm (cow-store-service-type): New variable.
  (cow-store-service): Rewrite using 'service'.
  (/etc/configuration-files): New procedure.
  (configuration-template-service-type,
  %configuration-template-service): New variables.
  (configuration-template-service): Remove.
  (installation-services): Adjust accordingly.  Adjust argument to
  'guix-service'.
* gnu/system/linux.scm (/etc-entry, pam-root-service): New procedures.
  (pam-root-service-type): New variable.
* gnu/system/shadow.scm (user-group->gexp, user-account->gexp,
  account-activation, etc-skel, account-service): New procedures.
  (account-service-type): New variable.
* tests/services.scm: New file.
* doc/guix.texi (Base Services, Desktop Services): Adjust accordingly.
  (Defining Services): Rewrite.
* doc/images/service-graph.dot: New file.
* doc.am (DOT_FILES): Add it.
* po/guix/POTFILES.in: Add gnu/services.scm.

1 files changed, 178 insertions, 0 deletions

diff --git a/gnu/services/dbus.scm b/gnu/services/dbus.scm
new file mode 100644
index 0000000000..e4ecd961c5
--- /dev/null
+++ b/gnu/services/dbus.scm
@@ -0,0 +1,178 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.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 dbus)
+  #:use-module (gnu services)
+  #:use-module (gnu services dmd)
+  #:use-module (gnu system shadow)
+  #:use-module (gnu packages glib)
+  #:use-module (gnu packages admin)
+  #:use-module (guix gexp)
+  #:use-module (guix records)
+  #:use-module (srfi srfi-1)
+  #:use-module (ice-9 match)
+  #:export (dbus-root-service-type
+            dbus-service))
+
+;;;
+;;; D-Bus.
+;;;
+
+(define-record-type* <dbus-configuration>
+  dbus-configuration make-dbus-configuration
+  dbus-configuration?
+  (dbus      dbus-configuration-dbus              ;<package>
+             (default dbus))
+  (services  dbus-configuration-services          ;list of <package>
+             (default '())))
+
+(define (dbus-configuration-directory dbus services)
+  "Return a configuration directory for @var{dbus} that includes the
+@code{etc/dbus-1/system.d} directories of each package listed in
+@var{services}."
+  (define build
+    #~(begin
+        (use-modules (sxml simple)
+                     (srfi srfi-1))
+
+        (define (services->sxml services)
+          ;; Return the SXML 'includedir' clauses for DIRS.
+          `(busconfig
+            ,@(append-map (lambda (dir)
+                            `((includedir
+                               ,(string-append dir "/etc/dbus-1/system.d"))
+                              (servicedir         ;for '.service' files
+                               ,(string-append dir "/share/dbus-1/services"))
+                              (servicedir       ;likewise, for auto-activation
+                               ,(string-append
+                                 dir
+                                 "/share/dbus-1/system-services"))))
+                          services)))
+
+        (mkdir #$output)
+        (copy-file (string-append #$dbus "/etc/dbus-1/system.conf")
+                   (string-append #$output "/system.conf"))
+
+        ;; The default 'system.conf' has an <includedir> clause for
+        ;; 'system.d', so create it.
+        (mkdir (string-append #$output "/system.d"))
+
+        ;; 'system-local.conf' is automatically included by the default
+        ;; 'system.conf', so this is where we stuff our own things.
+        (call-with-output-file (string-append #$output "/system-local.conf")
+          (lambda (port)
+            (sxml->xml (services->sxml (list #$@services))
+                       port)))))
+
+  (computed-file "dbus-configuration" build))
+
+(define %dbus-accounts
+  ;; Accounts used by the system bus.
+  (list (user-group (name "messagebus") (system? #t))
+        (user-account
+         (name "messagebus")
+         (group "messagebus")
+         (system? #t)
+         (comment "D-Bus system bus user")
+         (home-directory "/var/run/dbus")
+         (shell #~(string-append #$shadow "/sbin/nologin")))))
+
+(define (dbus-activation config)
+  "Return an activation gexp for D-Bus using @var{config}."
+  #~(begin
+      (use-modules (guix build utils))
+
+      (mkdir-p "/var/run/dbus")
+
+      (let ((user (getpwnam "messagebus")))
+        (chown "/var/run/dbus"
+               (passwd:uid user) (passwd:gid user)))
+
+      (unless (file-exists? "/etc/machine-id")
+        (format #t "creating /etc/machine-id...~%")
+        (let ((prog (string-append #$(dbus-configuration-dbus config)
+                                   "/bin/dbus-uuidgen")))
+          ;; XXX: We can't use 'system' because the initrd's
+          ;; guile system(3) only works when 'sh' is in $PATH.
+          (let ((pid (primitive-fork)))
+            (if (zero? pid)
+                (call-with-output-file "/etc/machine-id"
+                  (lambda (port)
+                    (close-fdes 1)
+                    (dup2 (port->fdes port) 1)
+                    (execl prog)))
+                (waitpid pid)))))))
+
+(define dbus-dmd-service
+  (match-lambda
+    (($ <dbus-configuration> dbus services)
+     (let ((conf (dbus-configuration-directory dbus services)))
+       (list (dmd-service
+              (documentation "Run the D-Bus system daemon.")
+              (provision '(dbus-system))
+              (requirement '(user-processes))
+              (start #~(make-forkexec-constructor
+                        (list (string-append #$dbus "/bin/dbus-daemon")
+                              "--nofork"
+                              (string-append "--config-file=" #$conf
+                                             "/system.conf"))))
+              (stop #~(make-kill-destructor))))))))
+
+(define dbus-root-service-type
+  (service-type (name 'dbus)
+                (extensions
+                 (list (service-extension dmd-root-service-type
+                                          dbus-dmd-service)
+                       (service-extension activation-service-type
+                                          dbus-activation)
+                       (service-extension account-service-type
+                                          (const %dbus-accounts))))
+
+                ;; Extensions consist of lists of packages (representing D-Bus
+                ;; services) that we just concatenate.
+                ;;
+                ;; FIXME: We need 'dbus-daemon-launch-helper' to be
+                ;; setuid-root for auto-activation to work.
+                (compose concatenate)
+
+                ;; The service's parameters field is extended by augmenting
+                ;; its <dbus-configuration> 'services' field.
+                (extend (lambda (config services)
+                          (dbus-configuration
+                           (inherit config)
+                           (services
+                            (append (dbus-configuration-services config)
+                                    services)))))))
+
+(define* (dbus-service #:key (dbus dbus) (services '()))
+  "Return a service that runs the \"system bus\", using @var{dbus}, with
+support for @var{services}.
+
+@uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
+facility.  Its system bus is used to allow system services to communicate and
+be notified of system-wide events.
+
+@var{services} must be a list of packages that provide an
+@file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
+and policy files.  For example, to allow avahi-daemon to use the system bus,
+@var{services} must be equal to @code{(list avahi)}."
+  (service dbus-root-service-type
+           (dbus-configuration (dbus dbus)
+                               (services services))))
+
+;;; dbus.scm ends here