services: Add docker-mailserver-service-type.

* rosenthal/services/mail.scm: New file.

rosenthal/services/mail.scm

@@ -0,0 +1,74 @@
+;; SPDX-FileCopyrightText: 2024 Hilton Chain <hako@ultrarare.space>
+;;
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+(define-module (rosenthal services mail)
+  #:use-module (srfi srfi-26)
+  #:use-module (guix records)
+  #:use-module (gnu services)
+  #:use-module (gnu services admin)
+  #:use-module (gnu services configuration)
+  #:use-module (gnu services docker)
+  #:export (docker-mailserver-configuration
+            docker-mailserver-service-type))
+
+;;;
+;;; Docker Mailserver
+;;; https://docker-mailserver.github.io/docker-mailserver/latest/
+;;;
+
+(define-configuration docker-mailserver-configuration
+  (data-directory
+   (string "/var/lib/docker-mailserver")
+   "Directory to store Docker Mailserver data.")
+  (log-file
+   (string "/var/log/docker-mailserver.log")
+   "Path to log file.")
+  (shepherd-requirement
+   (list-of-symbols '())
+   "List of Shepherd service dependencies.")
+  (options
+   (alist '())
+   "Alist of Docker Mailserver configuration.  See also
+@url{https://docker-mailserver.github.io/docker-mailserver/latest/config/environment/}.")
+  (extra-arguments
+   (list '())
+   "List of extra Docker arguments.")
+  (no-serialization))
+
+(define docker-mailserver-log-rotations
+  (match-record-lambda <docker-mailserver-configuration>
+      (log-file)
+    (list (log-rotation
+           (files (list log-file))))))
+
+(define docker-mailserver-oci-containers
+  (match-record-lambda <docker-mailserver-configuration>
+      (data-directory log-file shepherd-requirement options extra-arguments)
+    (let ((docker-mailserver-path
+           (cut string-append data-directory <>)))
+      (list (oci-container-configuration
+             (environment options)
+             (image "ghcr.io/docker-mailserver/docker-mailserver:latest")
+             (provision "docker-mailserver")
+             (requirement shepherd-requirement)
+             (log-file log-file)
+             (network "host")
+             (volumes
+              `((,(docker-mailserver-path "/data") . "/var/mail")
+                (,(docker-mailserver-path "/state") . "/var/mail-state")
+                (,(docker-mailserver-path "/logs") . "/var/log/mail")
+                (,(docker-mailserver-path "/config") . "/tmp/docker-mailserver")
+                ("/etc/localtime" . "/etc/localtime:ro")))
+             (extra-arguments extra-arguments))))))
+
+(define docker-mailserver-service-type
+  (service-type
+   (name 'docker-mailserver)
+   (extensions
+    (list (service-extension oci-container-service-type
+                             docker-mailserver-oci-containers)
+          (service-extension rottlog-service-type
+                             docker-mailserver-log-rotations)))
+   (default-value (docker-mailserver-configuration))
+   (description "Run Docker Mailserver.")))