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, 86 insertions, 58 deletions

diff --git a/gnu/services/databases.scm b/gnu/services/databases.scm
index 20f8a6977e..8fdd222a3b 100644
--- a/gnu/services/databases.scm
+++ b/gnu/services/databases.scm
@@ -19,12 +19,13 @@
 
 (define-module (gnu services databases)
   #:use-module (gnu services)
+  #:use-module (gnu services dmd)
   #:use-module (gnu system shadow)
   #:use-module (gnu packages admin)
   #:use-module (gnu packages databases)
   #:use-module (guix records)
-  #:use-module (guix store)
   #:use-module (guix gexp)
+  #:use-module (ice-9 match)
   #:export (postgresql-service))
 
 ;;; Commentary:
@@ -33,6 +34,14 @@
 ;;;
 ;;; Code:
 
+(define-record-type* <postgresql-configuration>
+  postgresql-configuration make-postgresql-configuration
+  postgresql-configuration?
+  (postgresql     postgresql-configuration-postgresql ;<package>
+                  (default postgresql))
+  (config-file    postgresql-configuration-file)
+  (data-directory postgresql-configuration-data-directory))
+
 (define %default-postgres-hba
   (plain-file "pg_hba.conf"
               "
@@ -49,6 +58,77 @@ host	all	all	::1/128 	trust"))
                    "hba_file = '" %default-postgres-hba "'\n"
                    "ident_file = '" %default-postgres-ident "\n"))
 
+(define %postgresql-accounts
+  (list (user-group (name "postgres") (system? #t))
+        (user-account
+         (name "postgres")
+         (group "postgres")
+         (system? #t)
+         (comment "PostgreSQL server user")
+         (home-directory "/var/empty")
+         (shell #~(string-append #$shadow "/sbin/nologin")))))
+
+(define postgresql-activation
+  (match-lambda
+    (($ <postgresql-configuration> postgresql config-file data-directory)
+     #~(begin
+         (use-modules (guix build utils)
+                      (ice-9 match))
+
+         (let ((user (getpwnam "postgres"))
+               (initdb (string-append #$postgresql "/bin/initdb")))
+           ;; Create db state directory.
+           (mkdir-p #$data-directory)
+           (chown #$data-directory (passwd:uid user) (passwd:gid user))
+
+           ;; Drop privileges and init state directory in a new
+           ;; process.  Wait for it to finish before proceeding.
+           (match (primitive-fork)
+             (0
+              ;; Exit with a non-zero status code if an exception is thrown.
+              (dynamic-wind
+                (const #t)
+                (lambda ()
+                  (setgid (passwd:gid user))
+                  (setuid (passwd:uid user))
+                  (primitive-exit (system* initdb "-D" #$data-directory)))
+                (lambda ()
+                  (primitive-exit 1))))
+             (pid (waitpid pid))))))))
+
+(define postgresql-dmd-service
+  (match-lambda
+    (($ <postgresql-configuration> postgresql config-file data-directory)
+     (let ((start-script
+            ;; Wrapper script that switches to the 'postgres' user before
+            ;; launching daemon.
+            (program-file "start-postgres"
+                          #~(let ((user (getpwnam "postgres"))
+                                  (postgres (string-append #$postgresql
+                                                           "/bin/postgres")))
+                              (setgid (passwd:gid user))
+                              (setuid (passwd:uid user))
+                              (system* postgres
+                                       (string-append "--config-file="
+                                                      #$config-file)
+                                       "-D" #$data-directory)))))
+       (list (dmd-service
+              (provision '(postgres))
+              (documentation "Run the PostgreSQL daemon.")
+              (requirement '(user-processes loopback))
+              (start #~(make-forkexec-constructor #$start-script))
+              (stop #~(make-kill-destructor))))))))
+
+(define postgresql-service-type
+  (service-type (name 'postgresql)
+                (extensions
+                 (list (service-extension dmd-root-service-type
+                                          postgresql-dmd-service)
+                       (service-extension activation-service-type
+                                          postgresql-activation)
+                       (service-extension account-service-type
+                                          (const %postgresql-accounts))))))
+
 (define* (postgresql-service #:key (postgresql postgresql)
                              (config-file %default-postgres-config)
                              (data-directory "/var/lib/postgresql/data"))
@@ -56,60 +136,8 @@ host	all	all	::1/128 	trust"))
 
 The PostgreSQL daemon loads its runtime configuration from @var{config-file}
 and stores the database cluster in @var{data-directory}."
-  ;; Wrapper script that switches to the 'postgres' user before launching
-  ;; daemon.
-  (define start-script
-    (program-file "start-postgres"
-                  #~(let ((user (getpwnam "postgres"))
-                          (postgres (string-append #$postgresql
-                                                   "/bin/postgres")))
-                      (setgid (passwd:gid user))
-                      (setuid (passwd:uid user))
-                      (system* postgres
-                               (string-append "--config-file=" #$config-file)
-                               "-D" #$data-directory))))
-
-  (define activate
-    #~(begin
-        (use-modules (guix build utils)
-                     (ice-9 match))
-
-        (let ((user (getpwnam "postgres"))
-              (initdb (string-append #$postgresql "/bin/initdb")))
-          ;; Create db state directory.
-          (mkdir-p #$data-directory)
-          (chown #$data-directory (passwd:uid user) (passwd:gid user))
-
-          ;; Drop privileges and init state directory in a new
-          ;; process.  Wait for it to finish before proceeding.
-          (match (primitive-fork)
-            (0
-             ;; Exit with a non-zero status code if an exception is thrown.
-             (dynamic-wind
-               (const #t)
-               (lambda ()
-                 (setgid (passwd:gid user))
-                 (setuid (passwd:uid user))
-                 (primitive-exit (system* initdb "-D" #$data-directory)))
-               (lambda ()
-                 (primitive-exit 1))))
-            (pid (waitpid pid))))))
-
-  (service
-   (provision '(postgres))
-   (documentation "Run the PostgreSQL daemon.")
-   (requirement '(user-processes loopback))
-   (start #~(make-forkexec-constructor #$start-script))
-   (stop #~(make-kill-destructor))
-   (activate activate)
-   (user-groups (list (user-group
-                       (name "postgres")
-                       (system? #t))))
-   (user-accounts (list (user-account
-                         (name "postgres")
-                         (group "postgres")
-                         (system? #t)
-                         (comment "PostgreSQL server user")
-                         (home-directory "/var/empty")
-                         (shell
-                          #~(string-append #$shadow "/sbin/nologin")))))))
+  (service postgresql-service-type
+           (postgresql-configuration
+            (postgresql postgresql)
+            (config-file config-file)
+            (data-directory data-directory))))