gnu: services: Add nginx-service.

* gnu/services/web.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* guix.texi ("Web Services"): New section.

doc/guix.texi

@@ -5592,6 +5592,7 @@ declaration.
 * X Window::                    Graphical display.
 * Desktop Services::            D-Bus and desktop services.
 * Database Services::           SQL databases.
+* Web Services::                Web servers.
 * Various Services::            Other services.
 @end menu
 
@@ -6111,6 +6112,26 @@ The PostgreSQL daemon loads its runtime configuration from
 @var{data-directory}.
 @end deffn
 
+@node Web Services
+@subsubsection Web Services
+
+The @code{(gnu services web)} module provides the following service:
+
+@deffn {Monadic Procedure} nginx-service [#:nginx nginx] @
+       [#:log-directory ``/var/log/nginx''] @
+       [#:run-directory ``/var/run/nginx''] @
+       [#:config-file]
+
+Return a service that runs @var{nginx}, the nginx web server.
+
+The nginx daemon loads its runtime configuration from @var{config-file}.
+Log files are written to @var{log-directory} and temporary runtime data
+files are written to @var{run-directory}.  For proper operation, these
+arguments should match what is in @var{config-file} to ensure that the
+directories are created when the service is activated.
+
+@end deffn
+
 @node Various Services
 @subsubsection Various Services
 

gnu-system.am

@@ -350,6 +350,7 @@ GNU_SYSTEM_MODULES =				\
   gnu/services/lirc.scm				\
   gnu/services/networking.scm			\
   gnu/services/ssh.scm				\
+  gnu/services/web.scm				\
   gnu/services/xorg.scm				\
 						\
   gnu/system.scm				\

gnu/services/web.scm

@@ -0,0 +1,97 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2015 David Thompson <davet@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 web)
+  #:use-module (gnu services)
+  #:use-module (gnu system shadow)
+  #:use-module (gnu packages admin)
+  #:use-module (gnu packages web)
+  #:use-module (guix records)
+  #:use-module (guix monads)
+  #:use-module (guix store)
+  #:use-module (guix gexp)
+  #:export (nginx-service))
+
+;;; Commentary:
+;;;
+;;; Web services.
+;;;
+;;; Code:
+
+(define (default-nginx-config log-directory run-directory)
+  (plain-file "nginx.conf"
+              (string-append
+               "user nginx nginx;\n"
+               "pid " run-directory "/pid;\n"
+               "error_log " log-directory "/error.log info;\n"
+               "http {\n"
+               "    access_log " log-directory "/access.log;\n"
+               "    root /var/www;\n"
+               "    server {}\n"
+               "}\n"
+               "events {}\n")))
+
+(define* (nginx-service #:key (nginx nginx)
+                        (log-directory "/var/log/nginx")
+                        (run-directory "/var/run/nginx")
+                        (config-file
+                         (default-nginx-config log-directory run-directory)))
+  "Return a service that runs NGINX, the nginx web server.
+
+The nginx daemon loads its runtime configuration from CONFIG-FIGLE, stores log
+files in LOG-DIRECTORY, and stores temporary runtime files in RUN-DIRECTORY."
+  (define nginx-binary
+    #~(string-append #$nginx "/sbin/nginx"))
+
+  (define (nginx-action . args)
+    #~(lambda _
+        (zero?
+         (system* #$nginx-binary "-c" #$config-file #$@args))))
+
+  (define activate
+    #~(begin
+        (use-modules (guix build utils))
+        (format #t "creating nginx log directory '~a'~%" #$log-directory)
+        (mkdir-p #$log-directory)
+        (format #t "creating nginx run directory '~a'~%" #$run-directory)
+        (mkdir-p #$run-directory)
+        ;; Check configuration file syntax.
+        (system* #$nginx-binary "-c" #$config-file "-t")))
+
+  (define nologin #~(string-append #$shadow "/sbin/nologin"))
+
+  ;; TODO: Add 'reload' action.
+  (mbegin %store-monad
+    (return
+     (service
+      (provision '(nginx))
+      (documentation "Run the nginx daemon.")
+      (requirement '(user-processes loopback))
+      (start (nginx-action "-p" run-directory))
+      (stop (nginx-action "-s" "stop"))
+      (activate activate)
+      (user-groups (list (user-group
+                          (name "nginx")
+                          (system? #t))))
+      (user-accounts (list (user-account
+                            (name "nginx")
+                            (group "nginx")
+                            (system? #t)
+                            (comment "nginx server user")
+                            (home-directory "/var/empty")
+                            (shell nologin))))))))