Merge branch 'master' into core-updates

9 files changed, 1153 insertions, 418 deletions

diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index 69e211ffa3..343123a377 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -55,7 +55,6 @@
   #:export (fstab-service-type
             root-file-system-service
             file-system-service-type
-            user-unmount-service
             swap-service
             user-processes-service-type
             host-name-service
@@ -464,7 +463,36 @@ FILE-SYSTEM."
        (start #~(const #t))
        (stop #~(const #f))))
 
-    (cons sink (map file-system-shepherd-service file-systems))))
+    (define known-mount-points
+      (map file-system-mount-point file-systems))
+
+    (define user-unmount
+      (shepherd-service
+       (documentation "Unmount manually-mounted file systems.")
+       (provision '(user-file-systems))
+       (start #~(const #t))
+       (stop #~(lambda args
+                 (define (known? mount-point)
+                   (member mount-point
+                           (cons* "/proc" "/sys" '#$known-mount-points)))
+
+                 ;; Make sure we don't keep the user's mount points busy.
+                 (chdir "/")
+
+                 (for-each (lambda (mount-point)
+                             (format #t "unmounting '~a'...~%" mount-point)
+                             (catch 'system-error
+                               (lambda ()
+                                 (umount mount-point))
+                               (lambda args
+                                 (let ((errno (system-error-errno args)))
+                                   (format #t "failed to unmount '~a': ~a~%"
+                                           mount-point (strerror errno))))))
+                           (filter (negate known?) (mount-points)))
+                 #f))))
+
+    (cons* sink user-unmount
+           (map file-system-shepherd-service file-systems))))
 
 (define file-system-service-type
   (service-type (name 'file-systems)
@@ -483,38 +511,6 @@ FILE-SYSTEM."
                  "Provide Shepherd services to mount and unmount the given
 file systems, as well as corresponding @file{/etc/fstab} entries.")))
 
-(define user-unmount-service-type
-  (shepherd-service-type
-   'user-file-systems
-   (lambda (known-mount-points)
-     (shepherd-service
-      (documentation "Unmount manually-mounted file systems.")
-      (provision '(user-file-systems))
-      (start #~(const #t))
-      (stop #~(lambda args
-                (define (known? mount-point)
-                  (member mount-point
-                          (cons* "/proc" "/sys" '#$known-mount-points)))
-
-                ;; Make sure we don't keep the user's mount points busy.
-                (chdir "/")
-
-                (for-each (lambda (mount-point)
-                            (format #t "unmounting '~a'...~%" mount-point)
-                            (catch 'system-error
-                              (lambda ()
-                                (umount mount-point))
-                              (lambda args
-                                (let ((errno (system-error-errno args)))
-                                  (format #t "failed to unmount '~a': ~a~%"
-                                          mount-point (strerror errno))))))
-                          (filter (negate known?) (mount-points)))
-                #f))))))
-
-(define (user-unmount-service known-mount-points)
-  "Return a service whose sole purpose is to unmount file systems not listed
-in KNOWN-MOUNT-POINTS when it is stopped."
-  (service user-unmount-service-type known-mount-points))
 
 
 ;;;
@@ -941,119 +937,122 @@ to use as the tty.  This is primarily useful for headless systems."
          ;; mingetty-shepherd-service).
          (requirement '(user-processes host-name udev))
 
-         (start #~(let ((tty #$(default-serial-port)))
-                    (if tty
-                        (make-forkexec-constructor
-                         (list #$(file-append util-linux "/sbin/agetty")
-                               #$@extra-options
-                               #$@(if eight-bits?
-                                      #~("--8bits")
-                                      #~())
-                               #$@(if no-reset?
-                                      #~("--noreset")
-                                      #~())
-                               #$@(if remote?
-                                      #~("--remote")
-                                      #~())
-                               #$@(if flow-control?
-                                      #~("--flow-control")
-                                      #~())
-                               #$@(if host
-                                      #~("--host" #$host)
-                                      #~())
-                               #$@(if no-issue?
-                                      #~("--noissue")
-                                      #~())
-                               #$@(if init-string
-                                      #~("--init-string" #$init-string)
-                                      #~())
-                               #$@(if no-clear?
-                                      #~("--noclear")
-                                      #~())
+         (start #~(lambda args
+                    (let ((defaulted-tty #$(or tty (default-serial-port))))
+                      (apply
+                       (if defaulted-tty
+                           (make-forkexec-constructor
+                            (list #$(file-append util-linux "/sbin/agetty")
+                                  #$@extra-options
+                                  #$@(if eight-bits?
+                                         #~("--8bits")
+                                         #~())
+                                  #$@(if no-reset?
+                                         #~("--noreset")
+                                         #~())
+                                  #$@(if remote?
+                                         #~("--remote")
+                                         #~())
+                                  #$@(if flow-control?
+                                         #~("--flow-control")
+                                         #~())
+                                  #$@(if host
+                                         #~("--host" #$host)
+                                         #~())
+                                  #$@(if no-issue?
+                                         #~("--noissue")
+                                         #~())
+                                  #$@(if init-string
+                                         #~("--init-string" #$init-string)
+                                         #~())
+                                  #$@(if no-clear?
+                                         #~("--noclear")
+                                         #~())
 ;;; FIXME This doesn't work as expected. According to agetty(8), if this option
 ;;; is not passed, then the default is 'auto'. However, in my tests, when that
 ;;; option is selected, agetty never presents the login prompt, and the
 ;;; term-ttyS0 service respawns every few seconds.
-                               #$@(if local-line
-                                      #~(#$(match local-line
-                                             ('auto "--local-line=auto")
-                                             ('always "--local-line=always")
-                                             ('never "-local-line=never")))
-                                      #~())
-                               #$@(if tty
-                                      #~()
-                                      #~("--keep-baud"))
-                               #$@(if extract-baud?
-                                      #~("--extract-baud")
-                                      #~())
-                               #$@(if skip-login?
-                                      #~("--skip-login")
-                                      #~())
-                               #$@(if no-newline?
-                                      #~("--nonewline")
-                                      #~())
-                               #$@(if login-options
-                                      #~("--login-options" #$login-options)
-                                      #~())
-                               #$@(if chroot
-                                      #~("--chroot" #$chroot)
-                                      #~())
-                               #$@(if hangup?
-                                      #~("--hangup")
-                                      #~())
-                               #$@(if keep-baud?
-                                      #~("--keep-baud")
-                                      #~())
-                               #$@(if timeout
-                                      #~("--timeout" #$(number->string timeout))
-                                      #~())
-                               #$@(if detect-case?
-                                      #~("--detect-case")
-                                      #~())
-                               #$@(if wait-cr?
-                                      #~("--wait-cr")
-                                      #~())
-                               #$@(if no-hints?
-                                      #~("--nohints?")
-                                      #~())
-                               #$@(if no-hostname?
-                                      #~("--nohostname")
-                                      #~())
-                               #$@(if long-hostname?
-                                      #~("--long-hostname")
-                                      #~())
-                               #$@(if erase-characters
-                                      #~("--erase-chars" #$erase-characters)
-                                      #~())
-                               #$@(if kill-characters
-                                      #~("--kill-chars" #$kill-characters)
-                                      #~())
-                               #$@(if chdir
-                                      #~("--chdir" #$chdir)
-                                      #~())
-                               #$@(if delay
-                                      #~("--delay" #$(number->string delay))
-                                      #~())
-                               #$@(if nice
-                                      #~("--nice" #$(number->string nice))
-                                      #~())
-                               #$@(if auto-login
-                                      (list "--autologin" auto-login)
-                                      '())
-                               #$@(if login-program
-                                      #~("--login-program" #$login-program)
-                                      #~())
-                               #$@(if login-pause?
-                                      #~("--login-pause")
-                                      #~())
-                               #$(or tty (default-serial-port))
-                               #$@(if baud-rate
-                                      #~(#$baud-rate)
-                                      #~())
-                               #$@(if term
-                                      #~(#$term)
-                                      #~()))))
-                        (const #f))) ; never start.
+                                  #$@(if local-line
+                                         #~(#$(match local-line
+                                                     ('auto "--local-line=auto")
+                                                     ('always "--local-line=always")
+                                                     ('never "-local-line=never")))
+                                         #~())
+                                  #$@(if tty
+                                         #~()
+                                         #~("--keep-baud"))
+                                  #$@(if extract-baud?
+                                         #~("--extract-baud")
+                                         #~())
+                                  #$@(if skip-login?
+                                         #~("--skip-login")
+                                         #~())
+                                  #$@(if no-newline?
+                                         #~("--nonewline")
+                                         #~())
+                                  #$@(if login-options
+                                         #~("--login-options" #$login-options)
+                                         #~())
+                                  #$@(if chroot
+                                         #~("--chroot" #$chroot)
+                                         #~())
+                                  #$@(if hangup?
+                                         #~("--hangup")
+                                         #~())
+                                  #$@(if keep-baud?
+                                         #~("--keep-baud")
+                                         #~())
+                                  #$@(if timeout
+                                         #~("--timeout" #$(number->string timeout))
+                                         #~())
+                                  #$@(if detect-case?
+                                         #~("--detect-case")
+                                         #~())
+                                  #$@(if wait-cr?
+                                         #~("--wait-cr")
+                                         #~())
+                                  #$@(if no-hints?
+                                         #~("--nohints?")
+                                         #~())
+                                  #$@(if no-hostname?
+                                         #~("--nohostname")
+                                         #~())
+                                  #$@(if long-hostname?
+                                         #~("--long-hostname")
+                                         #~())
+                                  #$@(if erase-characters
+                                         #~("--erase-chars" #$erase-characters)
+                                         #~())
+                                  #$@(if kill-characters
+                                         #~("--kill-chars" #$kill-characters)
+                                         #~())
+                                  #$@(if chdir
+                                         #~("--chdir" #$chdir)
+                                         #~())
+                                  #$@(if delay
+                                         #~("--delay" #$(number->string delay))
+                                         #~())
+                                  #$@(if nice
+                                         #~("--nice" #$(number->string nice))
+                                         #~())
+                                  #$@(if auto-login
+                                         (list "--autologin" auto-login)
+                                         '())
+                                  #$@(if login-program
+                                         #~("--login-program" #$login-program)
+                                         #~())
+                                  #$@(if login-pause?
+                                         #~("--login-pause")
+                                         #~())
+                                  defaulted-tty
+                                  #$@(if baud-rate
+                                         #~(#$baud-rate)
+                                         #~())
+                                  #$@(if term
+                                         #~(#$term)
+                                         #~())))
+                           (const #f)) ; never start.
+                       args))))
          (stop #~(make-kill-destructor)))))))
 
 (define agetty-service-type
diff --git a/gnu/services/cgit.scm b/gnu/services/cgit.scm
new file mode 100644
index 0000000000..a868d758a4
--- /dev/null
+++ b/gnu/services/cgit.scm
@@ -0,0 +1,686 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2018 Oleg Pykhalov <go.wigust@gmail.com>
+;;;
+;;; 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 cgit)
+  #:use-module (gnu packages admin)
+  #:use-module (gnu packages version-control)
+  #:use-module (gnu services base)
+  #:use-module (gnu services configuration)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu services web)
+  #:use-module (gnu services)
+  #:use-module (gnu system shadow)
+  #:use-module (guix gexp)
+  #:use-module (guix packages)
+  #:use-module (guix records)
+  #:use-module (guix store)
+  #:use-module (ice-9 match)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:export (repository-cgit-configuration
+            cgit-configuration
+            %cgit-configuration-nginx
+            cgit-configuration-nginx-config
+            opaque-cgit-configuration
+            cgit-service-type))
+
+;;; Commentary:
+;;;
+;;; This module provides a service definition for the Cgit a web frontend for
+;;; Git repositories written in C.
+;;;
+;;; Note: fields of <cgit-configuration> and <repository-cgit-configuration>
+;;; should be specified in the specific order.
+;;;
+;;; Code:
+
+(define %cgit-configuration-nginx
+  (nginx-server-configuration
+   (root cgit)
+   (locations
+    (list
+     (nginx-location-configuration
+      (uri "@cgit")
+      (body '("fastcgi_param SCRIPT_FILENAME $document_root/lib/cgit/cgit.cgi;"
+              "fastcgi_param PATH_INFO $uri;"
+              "fastcgi_param QUERY_STRING $args;"
+              "fastcgi_param HTTP_HOST $server_name;"
+              "fastcgi_pass 127.0.0.1:9000;")))))
+   (try-files (list "$uri" "@cgit"))
+   (listen '("80"))
+   (ssl-certificate #f)
+   (ssl-certificate-key #f)))
+
+
+;;;
+;;; Serialize <cgit-configuration>
+;;;
+
+(define (uglify-field-name field-name)
+  (let ((str (symbol->string field-name)))
+    (string-join (string-split (string-delete #\? str) #\-) "-")))
+
+(define (serialize-field field-name val)
+  (format #t "~a=~a\n" (uglify-field-name field-name) val))
+
+(define (serialize-string field-name val)
+  (if (string=? val "") "" (serialize-field field-name val)))
+
+(define (serialize-boolean field-name val)
+  (serialize-field field-name (if val 1 0)))
+
+(define (serialize-list field-name val)
+  (if (null? val) "" (serialize-field field-name (string-join val))))
+
+(define robots-list? list?)
+
+(define (serialize-robots-list field-name val)
+  (if (null? val) "" (serialize-field field-name (string-join val ", "))))
+
+(define (integer? val)
+  (exact-integer? val))
+
+(define (serialize-integer field-name val)
+  (serialize-field field-name val))
+
+(define (serialize-repository-cgit-configuration x)
+  (serialize-configuration x repository-cgit-configuration-fields))
+
+(define (repository-cgit-configuration-list? val)
+  (list? val))
+
+(define (serialize-repository-cgit-configuration-list field-name val)
+  (for-each serialize-repository-cgit-configuration val))
+
+
+;;;
+;;; Serialize <nginx-server-configuration>
+;;;
+
+(define (nginx-server-configuration-list? val)
+  (and (list? val) (and-map nginx-server-configuration? val)))
+
+(define (serialize-nginx-server-configuration-list field-name val)
+  #f)
+
+
+;;;
+;;; Serialize <repository-cgit-configuration>
+;;;
+
+(define (serialize-repo-field field-name val)
+  (format #t "repo.~a=~a\n" (uglify-field-name field-name) val))
+
+(define (serialize-repo-list field-name val)
+  (if (null? val) "" (serialize-repo-field field-name (string-join val))))
+
+(define repo-boolean? boolean?)
+
+(define (serialize-repo-boolean field-name val)
+  (serialize-repo-field field-name (if val 1 0)))
+
+(define (serialize-repo-integer field-name val)
+  (serialize-repo-field field-name val))
+
+(define repo-list? list?)
+
+(define repo-string? string?)
+
+(define (serialize-repo-string field-name val)
+  (if (string=? val "") "" (serialize-repo-field field-name val)))
+
+(define module-link-path? list?)
+
+(define (serialize-module-link-path field-name val)
+  (if (null? val) ""
+      (match val
+        ((path text)
+         (format #t "repo.~a.~a=~a\n"
+                 (string-drop-right (uglify-field-name 'module-link-path)
+                                    (string-length "-path"))
+                 path text)))))
+
+(define repository-directory? string?)
+
+(define (serialize-repository-directory _ val)
+  (if (string=? val "") "" (format #t "scan-path=~a\n" val)))
+
+(define mimetype-alist? list?)
+
+(define (serialize-mimetype-alist field-name val)
+  (format #t "# Mimetypes\n~a"
+          (string-join
+           (map (match-lambda
+                  ((extension mimetype)
+                   (format #f "mimetype.~a=~a"
+                           (symbol->string extension) mimetype)))
+                val) "\n")))
+
+(define-configuration repository-cgit-configuration
+  (snapshots
+   (repo-list '())
+   "A mask of snapshot formats for this repo that cgit generates links for,
+restricted by the global @code{snapshots} setting.")
+  (source-filter
+   (repo-string "")
+   "Override the default @code{source-filter}.")
+  (url
+   (repo-string "")
+   "The relative URL used to access the repository.")
+  (about-filter
+   (repo-string "")
+   "Override the default @code{about-filter}.")
+  (branch-sort
+   (repo-string "")
+   "Flag which, when set to @samp{age}, enables date ordering in the branch
+ref list, and when set to @samp{name} enables ordering by branch name.")
+  (clone-url
+   (repo-list '())
+   "A list of URLs which can be used to clone repo.")
+  (commit-filter
+   (repo-string "")
+   "Override the default @code{commit-filter}.")
+  (commit-sort
+   (repo-string "")
+   "Flag which, when set to @samp{date}, enables strict date ordering in the
+commit log, and when set to @samp{topo} enables strict topological ordering.")
+  (defbranch
+   (repo-string "")
+   "The name of the default branch for this repository.  If no such branch
+exists in the repository, the first branch name (when sorted) is used as
+default instead.  By default branch pointed to by HEAD, or \"master\" if there
+is no suitable HEAD.")
+  (desc
+   (repo-string "")
+   "The value to show as repository description.")
+  (homepage
+   (repo-string "")
+   "The value to show as repository homepage.")
+  (email-filter
+   (repo-string "")
+   "Override the default @code{email-filter}.")
+  (enable-commit-graph?
+   (repo-boolean #f)
+   "A flag which can be used to disable the global setting
+@code{enable-commit-graph?}.")
+  (enable-log-filecount?
+   (repo-boolean #f)
+   "A flag which can be used to disable the global setting
+@code{enable-log-filecount?}.")
+  (enable-log-linecount?
+   (repo-boolean #f)
+   "A flag which can be used to disable the global setting
+@code{enable-log-linecount?}.")
+  (enable-remote-branches?
+   (repo-boolean #f)
+   "Flag which, when set to @code{#t}, will make cgit display remote
+branches in the summary and refs views.")
+  (enable-subject-links?
+   (repo-boolean #f)
+   "A flag which can be used to override the global setting
+@code{enable-subject-links?}.")
+  (enable-html-serving?
+   (repo-boolean #f)
+   "A flag which can be used to override the global setting
+@code{enable-html-serving?}.")
+  (hide?
+   (repo-boolean #f)
+   "Flag which, when set to @code{#t}, hides the repository from the
+repository index.")
+  (ignore?
+   (repo-boolean #f)
+   "Flag which, when set to @samp{#t}, ignores the repository.")
+  (logo
+   (repo-string "")
+   "URL which specifies the source of an image which will be used as a
+logo on this repo’s pages.")
+  (logo-link
+   (repo-string "")
+   "URL loaded when clicking on the cgit logo image.")
+  (owner-filter
+   (repo-string "")
+   "Override the default @code{owner-filter}.")
+  (module-link
+   (repo-string "")
+   "Text which will be used as the formatstring for a hyperlink when a
+submodule is printed in a directory listing.  The arguments for the
+formatstring are the path and SHA1 of the submodule commit.")
+  (module-link-path
+   (module-link-path '())
+   "Text which will be used as the formatstring for a hyperlink when a
+submodule with the specified subdirectory path is printed in a directory
+listing.")
+  (max-stats
+   (repo-string "")
+   "Override the default maximum statistics period.")
+  (name
+   (repo-string "")
+   "The value to show as repository name.")
+  (owner
+   (repo-string "")
+   "A value used to identify the owner of the repository.")
+  (path
+   (repo-string "")
+   "An absolute path to the repository directory.")
+  (readme
+   (repo-string "")
+   "A path (relative to repo) which specifies a file to include verbatim
+as the \"About\" page for this repo.")
+  (section
+   (repo-string "")
+   "The name of the current repository section - all repositories defined
+after this option will inherit the current section name.")
+  (extra-options
+   (repo-list '())
+   "Extra options will be appended to cgitrc file."))
+
+;; Generate a <cgit-configuration> record, which may include a list of
+;; <repository-cgit-configuration>, <nginx-server-configuration>, <package>.
+(define-configuration cgit-configuration
+  (package
+   (package cgit)
+   "The CGIT package.")
+  (nginx
+   (nginx-server-configuration-list (list %cgit-configuration-nginx))
+   "NGINX configuration.")
+  (about-filter
+   (string "")
+   "Specifies a command which will be invoked to format the content of about
+pages (both top-level and for each repository).")
+  (agefile
+   (string "")
+   "Specifies a path, relative to each repository path, which can be used to
+specify the date and time of the youngest commit in the repository.")
+  (auth-filter
+   (string "")
+   "Specifies a command that will be invoked for authenticating repository
+access.")
+  (branch-sort
+   (string "name")
+   "Flag which, when set to @samp{age}, enables date ordering in the branch
+ref list, and when set @samp{name} enables ordering by branch name.")
+  (cache-root
+   (string "/var/cache/cgit")
+   "Path used to store the cgit cache entries.")
+  (cache-static-ttl
+   (integer -1)
+   "Number which specifies the time-to-live, in minutes, for the cached
+version of repository pages accessed with a fixed SHA1.")
+  (cache-dynamic-ttl
+   (integer 5)
+   "Number which specifies the time-to-live, in minutes, for the cached
+version of repository pages accessed without a fixed SHA1.")
+  (cache-repo-ttl
+   (integer 5)
+   "Number which specifies the time-to-live, in minutes, for the cached
+version of the repository summary page.")
+  (cache-root-ttl
+   (integer 5)
+   "Number which specifies the time-to-live, in minutes, for the cached
+version of the repository index page.")
+  (cache-scanrc-ttl
+   (integer 15)
+   "Number which specifies the time-to-live, in minutes, for the result of
+scanning a path for Git repositories.")
+  (cache-about-ttl
+   (integer 15)
+   "Number which specifies the time-to-live, in minutes, for the cached
+version of the repository about page.")
+  (cache-snapshot-ttl
+   (integer 5)
+   "Number which specifies the time-to-live, in minutes, for the cached
+version of snapshots.")
+  (cache-size
+   (integer 0)
+   "The maximum number of entries in the cgit cache. When set to
+@samp{0}, caching is disabled.")
+  (case-sensitive-sort?
+   (boolean #t)
+   "Sort items in the repo list case sensitively.")
+  (clone-prefix
+   (list '())
+   "List of common prefixes which, when combined with a repository URL,
+generates valid clone URLs for the repository.")
+  (clone-url
+   (list '())
+   "List of @code{clone-url} templates.")
+  (commit-filter
+   (string "")
+   "Command which will be invoked to format commit messages.")
+  (commit-sort
+   (string "git log")
+   "Flag which, when set to @samp{date}, enables strict date ordering in the
+commit log, and when set to @samp{topo} enables strict topological
+ordering.")
+  (css
+   (string "/share/cgit/cgit.css")
+   "URL which specifies the css document to include in all cgit pages.")
+  (email-filter
+   (string "")
+   "Specifies a command which will be invoked to format names and email
+address of committers, authors, and taggers, as represented in various
+places throughout the cgit interface.")
+  (embedded?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, will make cgit generate a HTML
+fragment suitable for embedding in other HTML pages.")
+  (enable-commit-graph?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
+commit history graph to the left of the commit messages in the
+repository log page.")
+  (enable-filter-overrides?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, allows all filter settings to be
+overridden in repository-specific cgitrc files.")
+  (enable-follow-links?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, allows users to follow a file in the
+log view.")
+  (enable-http-clone?
+   (boolean #t)
+   "If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
+clones.")
+  (enable-index-links?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, will make cgit generate extra links
+\"summary\", \"commit\", \"tree\" for each repo in the repository index.")
+  (enable-index-owner?
+   (boolean #t)
+   "Flag which, when set to @samp{#t}, will make cgit display the owner of
+each repo in the repository index.")
+  (enable-log-filecount?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, will make cgit print the number of
+modified files for each commit on the repository log page.")
+  (enable-log-linecount?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, will make cgit print the number of
+added and removed lines for each commit on the repository log page.")
+  (enable-remote-branches?
+   (boolean #f)
+   "Flag which, when set to @code{#t}, will make cgit display remote
+branches in the summary and refs views.")
+  (enable-subject-links?
+   (boolean #f)
+   "Flag which, when set to @code{1}, will make cgit use the subject of
+the parent commit as link text when generating links to parent commits
+in commit view.")
+  (enable-html-serving?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, will make cgit use the subject of the
+parent commit as link text when generating links to parent commits in
+commit view.")
+  (enable-tree-linenumbers?
+   (boolean #t)
+   "Flag which, when set to @samp{#t}, will make cgit generate linenumber
+links for plaintext blobs printed in the tree view.")
+  (enable-git-config?
+   (boolean #f)
+   "Flag which, when set to @samp{#f}, will allow cgit to use Git config to
+set any repo specific settings.")
+  (favicon
+   (string "/favicon.ico")
+   "URL used as link to a shortcut icon for cgit.")
+  (footer
+   (string "")
+   "The content of the file specified with this option will be included
+verbatim at the bottom of all pages (i.e. it replaces the standard
+\"generated by...\" message).")
+  (head-include
+   (string "")
+   "The content of the file specified with this option will be included
+verbatim in the HTML HEAD section on all pages.")
+  (header
+   (string "")
+   "The content of the file specified with this option will be included
+verbatim at the top of all pages.")
+  (include
+   (string "")
+   "Name of a configfile to include before the rest of the current config-
+file is parsed.")
+  (index-header
+   (string "")
+   "The content of the file specified with this option will be included
+verbatim above the repository index.")
+  (index-info
+   (string "")
+   "The content of the file specified with this option will be included
+verbatim below the heading on the repository index page.")
+  (local-time?
+   (boolean #f)
+   "Flag which, if set to @samp{#t}, makes cgit print commit and tag times
+in the servers timezone.")
+  (logo
+   (string "/share/cgit/cgit.png")
+   "URL which specifies the source of an image which will be used as a logo
+on all cgit pages.")
+  (logo-link
+   (string "")
+   "URL loaded when clicking on the cgit logo image.")
+  (owner-filter
+   (string "")
+   "Command which will be invoked to format the Owner column of the main
+page.")
+  (max-atom-items
+   (integer 10)
+   "Number of items to display in atom feeds view.")
+  (max-commit-count
+   (integer 50)
+   "Number of entries to list per page in \"log\" view.")
+  (max-message-length
+   (integer 80)
+   "Number of commit message characters to display in \"log\" view.")
+  (max-repo-count
+   (integer 50)
+   "Specifies the number of entries to list per page on the repository index
+page.")
+  (max-repodesc-length
+   (integer 80)
+   "Specifies the maximum number of repo description characters to display
+on the repository index page.")
+  (max-blob-size
+   (integer 0)
+   "Specifies the maximum size of a blob to display HTML for in KBytes.")
+  (max-stats
+   (string "")
+   "Maximum statistics period.  Valid values are @samp{week},@samp{month},
+@samp{quarter} and @samp{year}.")
+  (mimetype
+   (mimetype-alist '((gif "image/gif")
+                     (html "text/html")
+                     (jpg "image/jpeg")
+                     (jpeg "image/jpeg")
+                     (pdf "application/pdf")
+                     (png "image/png")
+                     (svg "image/svg+xml")))
+   "Mimetype for the specified filename extension.")
+  (mimetype-file
+   (string "")
+   "Specifies the file to use for automatic mimetype lookup.")
+  (module-link
+   (string "")
+   "Text which will be used as the formatstring for a hyperlink when a
+submodule is printed in a directory listing.")
+  (nocache?
+   (boolean #f)
+   "If set to the value @samp{#t} caching will be disabled.")
+  (noplainemail?
+   (boolean #f)
+   "If set to @samp{#t} showing full author email addresses will be
+disabled.")
+  (noheader?
+   (boolean #f)
+   "Flag which, when set to @samp{#t}, will make cgit omit the standard
+header on all pages.")
+  ;; TODO: cgit expects a file name
+  ;; that should be created from a list of strings provided by the user.
+  ;;
+  ;; (project-list
+  ;;    (string "")
+  ;;    "A list of subdirectories inside of @code{repository-directory},
+  ;; relative to it, that should loaded as Git repositories.")
+  (readme
+   (string "")
+   "Text which will be used as default value for @code{cgit-repo-readme}.")
+  (remove-suffix?
+   (boolean #f)
+   "If set to @code{#t} and @code{repository-directory} is enabled, if any
+repositories are found with a suffix of @code{.git}, this suffix will be
+removed for the URL and name.")
+  (renamelimit
+   (integer -1)
+   "Maximum number of files to consider when detecting renames.")
+  (repository-sort
+   (string "")
+   "The way in which repositories in each section are sorted.")
+  (robots
+   (robots-list (list "noindex" "nofollow"))
+   "Text used as content for the @code{robots} meta-tag.")
+  (root-desc
+   (string "a fast webinterface for the git dscm")
+   "Text printed below the heading on the repository index page.")
+  (root-readme
+   (string "")
+   "The content of the file specified with this option will be included
+verbatim below thef \"about\" link on the repository index page.")
+  (root-title
+   (string "")
+   "Text printed as heading on the repository index page.")
+  (scan-hidden-path
+   (boolean #f)
+   "If set to @samp{#t} and repository-directory is enabled,
+repository-directory will recurse into directories whose name starts with a
+period.  Otherwise, repository-directory will stay away from such directories,
+considered as \"hidden\".  Note that this does not apply to the \".git\"
+directory in non-bare repos.")
+  (snapshots
+   (list '())
+   "Text which specifies the default set of snapshot formats that cgit
+generates links for.")
+  (repository-directory
+   (repository-directory "/srv/git")
+   "Name of the directory to scan for repositories (represents
+@code{scan-path}).")
+  (section
+   (string "")
+   "The name of the current repository section - all repositories defined
+after this option will inherit the current section name.")
+  (section-sort
+   (string "")
+   "Flag which, when set to @samp{1}, will sort the sections on the repository
+listing by name.")
+  (section-from-path
+   (integer 0)
+   "A number which, if defined prior to repository-directory, specifies how
+many path elements from each repo path to use as a default section name.")
+  (side-by-side-diffs?
+   (boolean #f)
+   "If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
+default.")
+  (source-filter
+   (string "")
+   "Specifies a command which will be invoked to format plaintext blobs in the
+tree view.")
+  (summary-branches
+   (integer 10)
+   "Specifies the number of branches to display in the repository \"summary\"
+view.")
+  (summary-log
+   (integer 10)
+   "Specifies the number of log entries to display in the repository
+\"summary\" view.")
+  (summary-tags
+   (integer 10)
+   "Specifies the number of tags to display in the repository \"summary\"
+view.")
+  (strict-export
+   (string "")
+   "Filename which, if specified, needs to be present within the repository
+for cgit to allow access to that repository.")
+  (virtual-root
+   (string "/")
+   "URL which, if specified, will be used as root for all cgit links.")
+  (repositories
+   (repository-cgit-configuration-list '())
+   "A list of @dfn{cgit-repo} records to use with config.")
+  (extra-options
+   (list '())
+   "Extra options will be appended to cgitrc file."))
+
+(define-configuration opaque-cgit-configuration
+  (cgit
+   (package cgit)
+   "The cgit package.")
+  (cgitrc
+   (string (configuration-missing-field 'opaque-cgit-configuration 'cgitrc))
+   "The contents of the @code{cgitrc} to use.")
+  (cache-root
+   (string "/var/cache/cgit")
+   "Path used to store the cgit cache entries.")
+  (nginx
+   (nginx-server-configuration-list (list %cgit-configuration-nginx))
+   "NGINX configuration."))
+
+(define (cgit-activation config)
+  "Return the activation gexp for CONFIG."
+  (let* ((opaque-config? (opaque-cgit-configuration? config))
+         (config-str
+          (if opaque-config?
+              (opaque-cgit-configuration-cgitrc config)
+              (with-output-to-string
+                (lambda ()
+                  (serialize-configuration config
+                                           cgit-configuration-fields))))))
+    #~(begin
+        (use-modules (guix build utils))
+        (mkdir-p #$(if opaque-config?
+                       (opaque-cgit-configuration-cache-root config)
+                       (cgit-configuration-cache-root config)))
+        (copy-file #$(plain-file "cgitrc" config-str) "/etc/cgitrc"))))
+
+(define (cgit-configuration-nginx-config config)
+  (if (opaque-cgit-configuration? config)
+      (opaque-cgit-configuration-nginx config)
+      (cgit-configuration-nginx config)))
+
+(define cgit-service-type
+  (service-type
+   (name 'cgit)
+   (extensions
+    (list (service-extension activation-service-type
+                             cgit-activation)
+          (service-extension nginx-service-type
+                             cgit-configuration-nginx-config)
+
+          ;; Make sure fcgiwrap is instantiated.
+          (service-extension fcgiwrap-service-type
+                             (const #t))))
+   (default-value (cgit-configuration))
+   (description
+    "Run the cgit web interface, which allows users to browse Git
+repositories.")))
+
+(define (generate-cgit-documentation)
+  (generate-documentation
+   `((cgit-configuration
+      ,cgit-configuration-fields
+      (repositories repository-cgit-configuration))
+     (repository-cgit-configuration
+      ,repository-cgit-configuration-fields))
+   'cgit-configuration))
diff --git a/gnu/services/configuration.scm b/gnu/services/configuration.scm
index c45340f02f..707944cbe0 100644
--- a/gnu/services/configuration.scm
+++ b/gnu/services/configuration.scm
@@ -1,7 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2015 Andy Wingo <wingo@igalia.com>
 ;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
-;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
+;;; Copyright © 2017, 2018 Clément Lassieur <clement@lassieur.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -74,11 +74,12 @@
   (documentation configuration-field-documentation))
 
 (define (serialize-configuration config fields)
-  (for-each (lambda (field)
-              ((configuration-field-serializer field)
-               (configuration-field-name field)
-               ((configuration-field-getter field) config)))
-            fields))
+  #~(string-append
+     #$@(map (lambda (field)
+               ((configuration-field-serializer field)
+                (configuration-field-name field)
+                ((configuration-field-getter field) config)))
+             fields)))
 
 (define (validate-configuration config fields)
   (for-each (lambda (field)
@@ -105,7 +106,7 @@
              (define (maybe-stem? val)
                (or (eq? val 'disabled) (stem? val)))
              (define (serialize-maybe-stem field-name val)
-               (when (stem? val) (serialize-stem field-name val)))))))))
+               (if (stem? val) (serialize-stem field-name val) ""))))))))
 
 (define-syntax define-configuration
   (lambda (stx)
@@ -147,7 +148,7 @@
                    conf))))))))
 
 (define (serialize-package field-name val)
-  #f)
+  "")
 
 ;; A little helper to make it easier to document all those fields.
 (define (generate-documentation documentation documentation-name)
diff --git a/gnu/services/databases.scm b/gnu/services/databases.scm
index b34a67aa95..72927c4534 100644
--- a/gnu/services/databases.scm
+++ b/gnu/services/databases.scm
@@ -29,9 +29,25 @@
   #:use-module (guix modules)
   #:use-module (guix records)
   #:use-module (guix gexp)
+  #:use-module (srfi srfi-1)
   #:use-module (ice-9 match)
-  #:export (postgresql-configuration
+  #:export (<postgresql-config-file>
+            postgresql-config-file
+            postgresql-config-file?
+            postgresql-config-file-log-destination
+            postgresql-config-file-hba-file
+            postgresql-config-file-ident-file
+            postgresql-config-file-extra-config
+
+            <postgresql-configuration>
+            postgresql-configuration
             postgresql-configuration?
+            postgresql-configuration-postgresql
+            postgresql-configuration-port
+            postgresql-configuration-locale
+            postgresql-configuration-file
+            postgresql-configuration-data-directory
+
             postgresql-service
             postgresql-service-type
 
@@ -68,18 +84,6 @@
 ;;;
 ;;; Code:
 
-(define-record-type* <postgresql-configuration>
-  postgresql-configuration make-postgresql-configuration
-  postgresql-configuration?
-  (postgresql     postgresql-configuration-postgresql ;<package>
-                  (default postgresql))
-  (port           postgresql-configuration-port
-                  (default 5432))
-  (locale         postgresql-configuration-locale
-                  (default "en_US.utf8"))
-  (config-file    postgresql-configuration-file)
-  (data-directory postgresql-configuration-data-directory))
-
 (define %default-postgres-hba
   (plain-file "pg_hba.conf"
               "
@@ -89,13 +93,64 @@ host	all	all	::1/128 	trust"))
 
 (define %default-postgres-ident
   (plain-file "pg_ident.conf"
-             "# MAPNAME       SYSTEM-USERNAME         PG-USERNAME"))
+              "# MAPNAME       SYSTEM-USERNAME         PG-USERNAME"))
+
+(define-record-type* <postgresql-config-file>
+  postgresql-config-file make-postgresql-config-file
+  postgresql-config-file?
+  (log-destination postgresql-config-file-log-destination
+                   (default "syslog"))
+  (hba-file        postgresql-config-file-hba-file
+                   (default %default-postgres-hba))
+  (ident-file      postgresql-config-file-ident-file
+                   (default %default-postgres-ident))
+  (extra-config    postgresql-config-file-extra-config
+                   (default '())))
+
+(define-gexp-compiler (postgresql-config-file-compiler
+                       (file <postgresql-config-file>) system target)
+  (match file
+    (($ <postgresql-config-file> log-destination hba-file
+                                 ident-file extra-config)
+     (define (quote' string)
+       (if string
+           (list "'" string "'")
+           '()))
+
+     (define contents
+       (append-map
+        (match-lambda
+          ((key) '())
+          ((key . #f) '())
+          ((key values ...) `(,key " = " ,@values "\n")))
+
+        `(("log_destination" ,@(quote' log-destination))
+          ("hba_file" ,@(quote' hba-file))
+          ("ident_file" ,@(quote' ident-file))
+          ,@extra-config)))
+
+     (gexp->derivation
+      "postgresql.conf"
+      #~(call-with-output-file (ungexp output "out")
+          (lambda (port)
+            (display
+             (string-append #$@contents)
+             port)))
+      #:local-build? #t))))
 
-(define %default-postgres-config
-  (mixed-text-file "postgresql.conf"
-                   "log_destination = 'syslog'\n"
-                   "hba_file = '" %default-postgres-hba "'\n"
-                   "ident_file = '" %default-postgres-ident "'\n"))
+(define-record-type* <postgresql-configuration>
+  postgresql-configuration make-postgresql-configuration
+  postgresql-configuration?
+  (postgresql     postgresql-configuration-postgresql ;<package>
+                  (default postgresql))
+  (port           postgresql-configuration-port
+                  (default 5432))
+  (locale         postgresql-configuration-locale
+                  (default "en_US.utf8"))
+  (config-file    postgresql-configuration-file
+                  (default (postgresql-config-file)))
+  (data-directory postgresql-configuration-data-directory
+                  (default "/var/lib/postgresql/data")))
 
 (define %postgresql-accounts
   (list (user-group (name "postgres") (system? #t))
@@ -184,12 +239,13 @@ host	all	all	::1/128 	trust"))
                        (service-extension activation-service-type
                                           postgresql-activation)
                        (service-extension account-service-type
-                                          (const %postgresql-accounts))))))
+                                          (const %postgresql-accounts))))
+                (default-value (postgresql-configuration))))
 
 (define* (postgresql-service #:key (postgresql postgresql)
                              (port 5432)
                              (locale "en_US.utf8")
-                             (config-file %default-postgres-config)
+                             (config-file (postgresql-config-file))
                              (data-directory "/var/lib/postgresql/data"))
   "Return a service that runs @var{postgresql}, the PostgreSQL database server.
 
@@ -466,7 +522,8 @@ FLUSH PRIVILEGES;
           (service-extension activation-service-type
                              %mysql-activation)
           (service-extension shepherd-root-service-type
-                             mysql-shepherd-service)))))
+                             mysql-shepherd-service)))
+   (default-value (mysql-configuration))))
 
 (define* (mysql-service #:key (config (mysql-configuration)))
   "Return a service that runs @command{mysqld}, the MySQL or MariaDB
@@ -548,4 +605,5 @@ The optional @var{config} argument specifies the configuration for
                        (service-extension activation-service-type
                                           redis-activation)
                        (service-extension account-service-type
-                                          (const %redis-accounts))))))
+                                          (const %redis-accounts))))
+                (default-value (redis-configuration))))
diff --git a/gnu/services/dict.scm b/gnu/services/dict.scm
index c8403c0135..70b05e8f80 100644
--- a/gnu/services/dict.scm
+++ b/gnu/services/dict.scm
@@ -1,6 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2016 Sou Bunnbu <iyzsong@gmail.com>
-;;; Copyright © 2016, 2017 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2017 Huang Ying <huang.ying.caritas@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -150,6 +150,7 @@ database {
                               (gnu system file-systems)))
       (list (shepherd-service
              (provision '(dicod))
+             (requirement '(user-processes))
              (documentation "Run the dicod daemon.")
              (modules '((gnu build shepherd)
                         (gnu system file-systems)))
diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index ab90942739..573efa0433 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -1435,90 +1435,91 @@ greyed out, instead of only later giving \"not selectable\" popup error.
          (home-directory "/var/empty")
          (shell (file-append shadow "/sbin/nologin")))))
 
-(define %dovecot-activation
+(define (%dovecot-activation config)
   ;; Activation gexp.
-  #~(begin
-      (use-modules (guix build utils))
-      (define (mkdir-p/perms directory owner perms)
-        (mkdir-p directory)
-        (chown "/var/run/dovecot" (passwd:uid owner) (passwd:gid owner))
-        (chmod directory perms))
-      (define (build-subject parameters)
-        (string-concatenate
-         (map (lambda (pair)
-                (let ((k (car pair)) (v (cdr pair)))
-                  (define (escape-char str chr)
-                    (string-join (string-split str chr) (string #\\ chr)))
-                  (string-append "/" k "="
-                                 (escape-char (escape-char v #\=) #\/))))
-              (filter (lambda (pair) (cdr pair)) parameters))))
-      (define* (create-self-signed-certificate-if-absent
-                #:key private-key public-key (owner (getpwnam "root"))
-                (common-name (gethostname))
-                (organization-name "GuixSD")
-                (organization-unit-name "Default Self-Signed Certificate")
-                (subject-parameters `(("CN" . ,common-name)
-                                      ("O" . ,organization-name)
-                                      ("OU" . ,organization-unit-name)))
-                (subject (build-subject subject-parameters)))
-        ;; Note that by default, OpenSSL outputs keys in PEM format.  This
-        ;; is what we want.
-        (unless (file-exists? private-key)
-          (cond
-           ((zero? (system* (string-append #$openssl "/bin/openssl")
-                            "genrsa" "-out" private-key "2048"))
-            (chown private-key (passwd:uid owner) (passwd:gid owner))
-            (chmod private-key #o400))
-           (else
-            (format (current-error-port)
-                    "Failed to create private key at ~a.\n" private-key))))
-        (unless (file-exists? public-key)
-          (cond
-           ((zero? (system* (string-append #$openssl "/bin/openssl")
-                            "req" "-new" "-x509" "-key" private-key
-                            "-out" public-key "-days" "3650"
-                            "-batch" "-subj" subject))
-            (chown public-key (passwd:uid owner) (passwd:gid owner))
-            (chmod public-key #o444))
-           (else
-            (format (current-error-port)
-                    "Failed to create public key at ~a.\n" public-key)))))
-      (let ((user (getpwnam "dovecot")))
-        (mkdir-p/perms "/var/run/dovecot" user #o755)
-        (mkdir-p/perms "/var/lib/dovecot" user #o755)
-        (mkdir-p/perms "/etc/dovecot" user #o755)
-        (mkdir-p/perms "/etc/dovecot/private" user #o700)
-        (create-self-signed-certificate-if-absent
-         #:private-key "/etc/dovecot/private/default.pem"
-         #:public-key "/etc/dovecot/default.pem"
-         #:owner (getpwnam "root")
-         #:common-name (format #f "Dovecot service on ~a" (gethostname))))))
+  (let ((config-str
+         (cond
+          ((opaque-dovecot-configuration? config)
+           (opaque-dovecot-configuration-string config))
+          (else
+           (with-output-to-string
+             (lambda ()
+               (serialize-configuration config
+                                        dovecot-configuration-fields)))))))
+    #~(begin
+        (use-modules (guix build utils))
+        (define (mkdir-p/perms directory owner perms)
+          (mkdir-p directory)
+          (chown "/var/run/dovecot" (passwd:uid owner) (passwd:gid owner))
+          (chmod directory perms))
+        (define (build-subject parameters)
+          (string-concatenate
+           (map (lambda (pair)
+                  (let ((k (car pair)) (v (cdr pair)))
+                    (define (escape-char str chr)
+                      (string-join (string-split str chr) (string #\\ chr)))
+                    (string-append "/" k "="
+                                   (escape-char (escape-char v #\=) #\/))))
+                (filter (lambda (pair) (cdr pair)) parameters))))
+        (define* (create-self-signed-certificate-if-absent
+                  #:key private-key public-key (owner (getpwnam "root"))
+                  (common-name (gethostname))
+                  (organization-name "GuixSD")
+                  (organization-unit-name "Default Self-Signed Certificate")
+                  (subject-parameters `(("CN" . ,common-name)
+                                        ("O" . ,organization-name)
+                                        ("OU" . ,organization-unit-name)))
+                  (subject (build-subject subject-parameters)))
+          ;; Note that by default, OpenSSL outputs keys in PEM format.  This
+          ;; is what we want.
+          (unless (file-exists? private-key)
+            (cond
+             ((zero? (system* (string-append #$openssl "/bin/openssl")
+                              "genrsa" "-out" private-key "2048"))
+              (chown private-key (passwd:uid owner) (passwd:gid owner))
+              (chmod private-key #o400))
+             (else
+              (format (current-error-port)
+                      "Failed to create private key at ~a.\n" private-key))))
+          (unless (file-exists? public-key)
+            (cond
+             ((zero? (system* (string-append #$openssl "/bin/openssl")
+                              "req" "-new" "-x509" "-key" private-key
+                              "-out" public-key "-days" "3650"
+                              "-batch" "-subj" subject))
+              (chown public-key (passwd:uid owner) (passwd:gid owner))
+              (chmod public-key #o444))
+             (else
+              (format (current-error-port)
+                      "Failed to create public key at ~a.\n" public-key)))))
+        (let ((user (getpwnam "dovecot")))
+          (mkdir-p/perms "/var/run/dovecot" user #o755)
+          (mkdir-p/perms "/var/lib/dovecot" user #o755)
+          (mkdir-p/perms "/etc/dovecot" user #o755)
+          (copy-file #$(plain-file "dovecot.conf" config-str)
+                     "/etc/dovecot/dovecot.conf")
+          (mkdir-p/perms "/etc/dovecot/private" user #o700)
+          (create-self-signed-certificate-if-absent
+           #:private-key "/etc/dovecot/private/default.pem"
+           #:public-key "/etc/dovecot/default.pem"
+           #:owner (getpwnam "root")
+           #:common-name (format #f "Dovecot service on ~a" (gethostname)))))))
 
 (define (dovecot-shepherd-service config)
   "Return a list of <shepherd-service> for CONFIG."
-  (let* ((config-str
-          (cond
-           ((opaque-dovecot-configuration? config)
-            (opaque-dovecot-configuration-string config))
-           (else
-            (with-output-to-string
-              (lambda ()
-                (serialize-configuration config
-                                         dovecot-configuration-fields))))))
-         (config-file (plain-file "dovecot.conf" config-str))
-         (dovecot (if (opaque-dovecot-configuration? config)
-                      (opaque-dovecot-configuration-dovecot config)
-                      (dovecot-configuration-dovecot config))))
+  (let ((dovecot (if (opaque-dovecot-configuration? config)
+                     (opaque-dovecot-configuration-dovecot config)
+                     (dovecot-configuration-dovecot config))))
     (list (shepherd-service
            (documentation "Run the Dovecot POP3/IMAP mail server.")
            (provision '(dovecot))
            (requirement '(networking))
            (start #~(make-forkexec-constructor
                      (list (string-append #$dovecot "/sbin/dovecot")
-                           "-F" "-c" #$config-file)))
+                           "-F")))
            (stop #~(make-forkexec-constructor
                     (list (string-append #$dovecot "/sbin/dovecot")
-                          "-c" #$config-file "stop")))))))
+                          "stop")))))))
 
 (define %dovecot-pam-services
   (list (unix-pam-service "dovecot")))
@@ -1533,7 +1534,7 @@ greyed out, instead of only later giving \"not selectable\" popup error.
                        (service-extension pam-root-service-type
                                           (const %dovecot-pam-services))
                        (service-extension activation-service-type
-                                          (const %dovecot-activation))))))
+                                          %dovecot-activation)))))
 
 (define* (dovecot-service #:key (config (dovecot-configuration)))
   "Return a service that runs @command{dovecot}, a mail server that can run
diff --git a/gnu/services/messaging.scm b/gnu/services/messaging.scm
index 427e2121f6..80ffed0f2f 100644
--- a/gnu/services/messaging.scm
+++ b/gnu/services/messaging.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
+;;; Copyright © 2017, 2018 Clément Lassieur <clement@lassieur.org>
 ;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
 ;;; Copyright © 2015, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
 ;;;
@@ -115,16 +115,9 @@
                  "_")))
 
 (define (serialize-field field-name val)
-  (format #t "~a = ~a;\n" (uglify-field-name field-name) val))
+  #~(format #f "~a = ~a;\n" #$(uglify-field-name field-name) #$val))
 (define (serialize-field-list field-name val)
-  (serialize-field field-name
-                   (with-output-to-string
-                     (lambda ()
-                       (format #t "{\n")
-                       (for-each (lambda (x)
-                                   (format #t "~a;\n" x))
-                                 val)
-                       (format #t "}")))))
+  (serialize-field field-name #~(format #f "{\n~@{~a;\n~}}" #$@val)))
 
 (define (serialize-boolean field-name val)
   (serialize-field field-name (if val "true" "false")))
@@ -140,17 +133,17 @@
 (define (non-negative-integer? val)
   (and (exact-integer? val) (not (negative? val))))
 (define (serialize-non-negative-integer field-name val)
-  (serialize-field field-name val))
+  (serialize-field field-name (number->string val)))
 (define-maybe non-negative-integer)
 
 (define (non-negative-integer-list? val)
   (and (list? val) (and-map non-negative-integer? val)))
 (define (serialize-non-negative-integer-list field-name val)
-  (serialize-field-list field-name val))
+  (serialize-field-list field-name (map number->string val)))
 (define-maybe non-negative-integer-list)
 
 (define (enclose-quotes s)
-  (format #f "\"~a\"" s))
+  #~(string-append "\"" #$s "\""))
 (define (serialize-string field-name val)
   (serialize-field field-name (enclose-quotes val)))
 (define-maybe string)
@@ -183,10 +176,22 @@
   (serialize-string-list field-name val))
 (define-maybe file-name)
 
+(define (file-object? val)
+  (or (file-like? val) (file-name? val)))
+(define (serialize-file-object field-name val)
+  (serialize-string field-name val))
+(define-maybe file-object)
+
+(define (file-object-list? val)
+  (and (list? val) (and-map file-object? val)))
+(define (serialize-file-object-list field-name val)
+  (serialize-string-list field-name val))
+(define-maybe file-object)
+
 (define (raw-content? val)
   (not (eq? val 'disabled)))
 (define (serialize-raw-content field-name val)
-  (format #t "~a" val))
+  val)
 (define-maybe raw-content)
 
 (define-configuration mod-muc-configuration
@@ -224,12 +229,12 @@ just joined the room."))
    "Path to your certificate file.")
 
   (capath
-   (file-name "/etc/ssl/certs")
+   (file-object "/etc/ssl/certs")
    "Path to directory containing root certificates that you wish Prosody to
 trust when verifying the certificates of remote servers.")
 
   (cafile
-   (maybe-file-name 'disabled)
+   (maybe-file-object 'disabled)
    "Path to a file containing root certificates that you wish Prosody to trust.
 Similar to @code{capath} but with all certificates concatenated together.")
 
@@ -273,9 +278,8 @@ can create such a file with:
    (maybe-string 'disabled)
    "Password for encrypted private keys."))
 (define (serialize-ssl-configuration field-name val)
-  (format #t "ssl = {\n")
-  (serialize-configuration val ssl-configuration-fields)
-  (format #t "};\n"))
+  #~(format #f "ssl = {\n~a};\n"
+            #$(serialize-configuration val ssl-configuration-fields)))
 (define-maybe ssl-configuration)
 
 (define %default-modules-enabled
@@ -303,20 +307,23 @@ can create such a file with:
   (define (virtualhost-configuration-list? val)
     (and (list? val) (and-map virtualhost-configuration? val)))
   (define (serialize-virtualhost-configuration-list l)
-    (for-each
-     (lambda (val) (serialize-virtualhost-configuration val)) l))
+    #~(string-append
+       #$@(map (lambda (val)
+                 (serialize-virtualhost-configuration val)) l)))
 
   (define (int-component-configuration-list? val)
     (and (list? val) (and-map int-component-configuration? val)))
   (define (serialize-int-component-configuration-list l)
-    (for-each
-     (lambda (val) (serialize-int-component-configuration val)) l))
+    #~(string-append
+       #$@(map (lambda (val)
+                 (serialize-int-component-configuration val)) l)))
 
   (define (ext-component-configuration-list? val)
     (and (list? val) (and-map ext-component-configuration? val)))
   (define (serialize-ext-component-configuration-list l)
-    (for-each
-     (lambda (val) (serialize-ext-component-configuration val)) l))
+    #~(string-append
+       #$@(map (lambda (val)
+                 (serialize-ext-component-configuration val)) l)))
 
   (define-all-configurations prosody-configuration
     (prosody
@@ -331,7 +338,7 @@ can create such a file with:
      global)
 
     (plugin-paths
-     (file-name-list '())
+     (file-object-list '())
      "Additional plugin directories.  They are searched in all the specified
 paths in order.  See @url{https://prosody.im/doc/plugins_directory}."
      global)
@@ -372,7 +379,7 @@ should you want to disable them then add them to this list."
      common)
 
     (groups-file
-     (file-name "/var/lib/prosody/sharedgroups.txt")
+     (file-object "/var/lib/prosody/sharedgroups.txt")
      "Path to a text file where the shared groups are defined.  If this path is
 empty then @samp{mod_groups} does nothing.  See
 @url{https://prosody.im/doc/modules/mod_groups}."
@@ -566,8 +573,9 @@ See also @url{https://prosody.im/doc/modules/mod_muc}."
                '(domain))))
   (let ((domain (virtualhost-configuration-domain config))
         (rest (filter rest? virtualhost-configuration-fields)))
-    (format #t "VirtualHost \"~a\"\n" domain)
-    (serialize-configuration config rest)))
+    #~(string-append
+       #$(format #f "VirtualHost \"~a\"\n" domain)
+       #$(serialize-configuration config rest))))
 
 ;; Serialize Component line first.
 (define (serialize-int-component-configuration config)
@@ -577,8 +585,9 @@ See also @url{https://prosody.im/doc/modules/mod_muc}."
   (let ((hostname (int-component-configuration-hostname config))
         (plugin (int-component-configuration-plugin config))
         (rest (filter rest? int-component-configuration-fields)))
-    (format #t "Component \"~a\" \"~a\"\n" hostname plugin)
-    (serialize-configuration config rest)))
+    #~(string-append
+       #$(format #f "Component \"~a\" \"~a\"\n" hostname plugin)
+       #$(serialize-configuration config rest))))
 
 ;; Serialize Component line first.
 (define (serialize-ext-component-configuration config)
@@ -587,22 +596,24 @@ See also @url{https://prosody.im/doc/modules/mod_muc}."
                '(hostname))))
   (let ((hostname (ext-component-configuration-hostname config))
         (rest (filter rest? ext-component-configuration-fields)))
-    (format #t "Component \"~a\"\n" hostname)
-    (serialize-configuration config rest)))
+    #~(string-append
+       #$(format #f "Component \"~a\"\n" hostname)
+       #$(serialize-configuration config rest))))
 
 ;; Serialize virtualhosts and components last.
 (define (serialize-prosody-configuration config)
   (define (rest? field)
     (not (memq (configuration-field-name field)
                '(virtualhosts int-components ext-components))))
-  (let ((rest (filter rest? prosody-configuration-fields)))
-    (serialize-configuration config rest))
-  (serialize-virtualhost-configuration-list
-   (prosody-configuration-virtualhosts config))
-  (serialize-int-component-configuration-list
-   (prosody-configuration-int-components config))
-  (serialize-ext-component-configuration-list
-   (prosody-configuration-ext-components config)))
+  #~(string-append
+     #$(let ((rest (filter rest? prosody-configuration-fields)))
+         (serialize-configuration config rest))
+     #$(serialize-virtualhost-configuration-list
+        (prosody-configuration-virtualhosts config))
+     #$(serialize-int-component-configuration-list
+        (prosody-configuration-int-components config))
+     #$(serialize-ext-component-configuration-list
+        (prosody-configuration-ext-components config))))
 
 (define-configuration opaque-prosody-configuration
   (prosody
@@ -646,13 +657,12 @@ See also @url{https://prosody.im/doc/modules/mod_muc}."
          (default-certs-dir "/etc/prosody/certs")
          (data-path (prosody-configuration-data-path config))
          (pidfile-dir (dirname (prosody-configuration-pidfile config)))
-         (config-str
-          (if (opaque-prosody-configuration? config)
-              (opaque-prosody-configuration-prosody.cfg.lua config)
-              (with-output-to-string
-                (lambda ()
-                  (serialize-prosody-configuration config)))))
-         (config-file (plain-file "prosody.cfg.lua" config-str)))
+         (config-str (if (opaque-prosody-configuration? config)
+                         (opaque-prosody-configuration-prosody.cfg.lua config)
+                         #~(begin
+                             (use-modules (ice-9 format))
+                             #$(serialize-prosody-configuration config))))
+         (config-file (mixed-text-file "prosody.cfg.lua" config-str)))
     #~(begin
         (use-modules (guix build utils))
         (define %user (getpw "prosody"))
diff --git a/gnu/services/networking.scm b/gnu/services/networking.scm
index 5ba3c5eed6..6ac440fd26 100644
--- a/gnu/services/networking.scm
+++ b/gnu/services/networking.scm
@@ -1,7 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
-;;; Copyright © 2016 Efraim Flashner <efraim@flashner.co.il>
+;;; Copyright © 2016, 2018 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2016 John Darrington <jmd@gnu.org>
 ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
 ;;; Copyright © 2017 Thomas Danckaert <post@thomasdanckaert.be>
@@ -64,6 +64,10 @@
             ntp-service
             ntp-service-type
 
+            openntpd-configuration
+            openntpd-configuration?
+            openntpd-service-type
+
             inetd-configuration
             inetd-entry
             inetd-service-type
@@ -448,6 +452,102 @@ make an initial adjustment of more than 1,000 seconds."
 
 
 ;;;
+;;; OpenNTPD.
+;;;
+
+(define-record-type* <openntpd-configuration>
+  openntpd-configuration make-openntpd-configuration
+  openntpd-configuration?
+  (openntpd                openntpd-configuration-openntpd
+                           (default openntpd))
+  (listen-on               openntpd-listen-on
+                           (default '("127.0.0.1"
+                                      "::1")))
+  (query-from              openntpd-query-from
+                           (default '()))
+  (sensor                  openntpd-sensor
+                           (default '()))
+  (server                  openntpd-server
+                           (default %ntp-servers))
+  (servers                 openntpd-servers
+                           (default '()))
+  (constraint-from         openntpd-constraint-from
+                           (default '()))
+  (constraints-from        openntpd-constraints-from
+                           (default '()))
+  (allow-large-adjustment? openntpd-allow-large-adjustment?
+                           (default #f))) ; upstream default
+
+(define (openntpd-shepherd-service config)
+  (match-record config <openntpd-configuration>
+    (openntpd listen-on query-from sensor server servers constraint-from
+              constraints-from allow-large-adjustment?)
+    (let ()
+      (define config
+        (string-join
+          (filter-map
+            (lambda (field value)
+              (string-join
+                (map (cut string-append field <> "\n")
+                     value)))
+            '("listen on " "query from " "sensor " "server " "servers "
+              "constraint from ")
+            (list listen-on query-from sensor server servers constraint-from))
+          ;; The 'constraints from' field needs to be enclosed in double quotes.
+          (string-join
+            (map (cut string-append "constraints from \"" <> "\"\n")
+                 constraints-from))))
+
+      (define ntpd.conf
+        (plain-file "ntpd.conf" config))
+
+      (list (shepherd-service
+              (provision '(ntpd))
+              (documentation "Run the Network Time Protocol (NTP) daemon.")
+              (requirement '(user-processes networking))
+              (start #~(make-forkexec-constructor
+                         (list (string-append #$openntpd "/sbin/ntpd")
+                               "-f" #$ntpd.conf
+                               "-d" ;; don't daemonize
+                               #$@(if allow-large-adjustment?
+                                    '("-s")
+                                    '()))
+                         ;; When ntpd is daemonized it repeatedly tries to respawn
+                         ;; while running, leading shepherd to disable it.  To
+                         ;; prevent spamming stderr, redirect output to logfile.
+                         #:log-file "/var/log/ntpd"))
+              (stop #~(make-kill-destructor)))))))
+
+(define (openntpd-service-activation config)
+  "Return the activation gexp for CONFIG."
+  (with-imported-modules '((guix build utils))
+    #~(begin
+        (use-modules (guix build utils))
+
+        (mkdir-p "/var/db")
+        (mkdir-p "/var/run")
+        (unless (file-exists? "/var/db/ntpd.drift")
+          (with-output-to-file "/var/db/ntpd.drift"
+                               (lambda _
+                                 (format #t "0.0")))))))
+
+(define openntpd-service-type
+  (service-type (name 'openntpd)
+                (extensions
+                 (list (service-extension shepherd-root-service-type
+                                          openntpd-shepherd-service)
+                       (service-extension account-service-type
+                                          (const %ntp-accounts))
+                       (service-extension activation-service-type
+                                          openntpd-service-activation)))
+                (default-value (openntpd-configuration))
+                (description
+                 "Run the @command{ntpd}, the Network Time Protocol (NTP)
+daemon, as implemented by @uref{http://www.openntpd.org, OpenNTPD}.  The
+daemon will keep the system clock synchronized with that of the given servers.")))
+
+
+;;;
 ;;; Inetd.
 ;;;
 
diff --git a/gnu/services/version-control.scm b/gnu/services/version-control.scm
index 7166ed3d4f..afead87ec7 100644
--- a/gnu/services/version-control.scm
+++ b/gnu/services/version-control.scm
@@ -38,26 +38,6 @@
             git-daemon-configuration
             git-daemon-configuration?
 
-            <cgit-configuration-file>
-            cgit-configuration-file
-            cgit-configuration-file?
-            cgit-configuration-file-css
-            cgit-configuration-file-logo
-            cgit-configuration-file-robots
-            cgit-configuration-file-virtual-root
-            cgit-configuration-file-repository-directory
-
-            <cgit-configuration>
-            cgit-configuration
-            cgit-configuration?
-            cgit-configuration-config-file
-            cgit-configuration-package
-
-            %cgit-configuration-nginx
-            cgit-configuration-nginx-config
-
-            cgit-service-type
-
             git-http-configuration
             git-http-configuration?
             git-http-nginx-location-configuration))
@@ -174,107 +154,6 @@ access to exported repositories under @file{/srv/git}."
 
 
 ;;;
-;;; Cgit
-;;;
-
-(define-record-type* <cgit-configuration-file>
-  cgit-configuration-file
-  make-cgit-configuration-file
-  cgit-configuration-file?
-  (css                  cgit-configuration-file-css                  ; string
-                        (default "/share/cgit/cgit.css"))
-  (logo                 cgit-configuration-file-logo                 ; string
-                        (default "/share/cgit/cgit.png"))
-  (robots               cgit-configuration-file-robots               ; list
-                        (default '("noindex" "nofollow")))
-  (virtual-root         cgit-configuration-file-virtual-root         ; string
-                        (default "/"))
-  (repository-directory cgit-configuration-file-repository-directory ; string
-                        (default "/srv/git")))
-
-(define (cgit-configuration-robots-string robots)
-  (string-join robots ", "))
-
-(define-gexp-compiler (cgit-configuration-file-compiler
-                       (file <cgit-configuration-file>) system target)
-  (match file
-    (($ <cgit-configuration-file> css logo
-                                  robots virtual-root repository-directory)
-     (apply text-file* "cgitrc"
-            (letrec-syntax ((option (syntax-rules ()
-                                      ((_ key value)
-                                       (if value
-                                           `(,key "=" ,value "\n")
-                                           '()))))
-                            (key/value (syntax-rules ()
-                                         ((_ (key value) rest ...)
-                                          (append (option key value)
-                                                  (key/value rest ...)))
-                                         ((_)
-                                          '()))))
-              (key/value ("css" css)
-                         ("logo" logo)
-                         ("robots" (cgit-configuration-robots-string robots))
-                         ("virtual-root" virtual-root)
-                         ("scan-path" repository-directory)))))))
-
-(define %cgit-configuration-nginx
-  (list
-   (nginx-server-configuration
-    (root cgit)
-    (locations
-     (list
-      (nginx-location-configuration
-       (uri "@cgit")
-       (body '("fastcgi_param SCRIPT_FILENAME $document_root/lib/cgit/cgit.cgi;"
-               "fastcgi_param PATH_INFO $uri;"
-               "fastcgi_param QUERY_STRING $args;"
-               "fastcgi_param HTTP_HOST $server_name;"
-               "fastcgi_pass 127.0.0.1:9000;")))))
-    (try-files (list "$uri" "@cgit"))
-    (listen '("80"))
-    (ssl-certificate #f)
-    (ssl-certificate-key #f))))
-
-(define-record-type* <cgit-configuration>
-  cgit-configuration make-cgit-configuration
-  cgit-configuration?
-  (config-file cgit-configuration-config-file
-               (default (cgit-configuration-file)))
-  (package cgit-configuration-package
-           (default cgit))
-  (nginx cgit-configuration-nginx
-         (default %cgit-configuration-nginx)))
-
-(define (cgit-activation config)
-  ;; Cgit compiled with default configuration path
-  #~(begin
-      (use-modules (guix build utils))
-      (mkdir-p "/var/cache/cgit")
-      (copy-file #$(cgit-configuration-config-file config) "/etc/cgitrc")))
-
-(define (cgit-configuration-nginx-config config)
-  (cgit-configuration-nginx config))
-
-(define cgit-service-type
-  (service-type
-   (name 'cgit)
-   (extensions
-    (list (service-extension activation-service-type
-                             cgit-activation)
-          (service-extension nginx-service-type
-                             cgit-configuration-nginx-config)
-
-          ;; Make sure fcgiwrap is instantiated.
-          (service-extension fcgiwrap-service-type
-                             (const #t))))
-   (default-value (cgit-configuration))
-   (description
-    "Run the Cgit web interface, which allows users to browse Git
-repositories.")))
-
-
-;;;
 ;;; HTTP access.  Add the result of calling
 ;;; git-http-nginx-location-configuration to an nginx-server-configuration's
 ;;; "locations" field.