dfsg-services: Add tailscale service.

dfsg/contrib/services/tailscale.scm

@@ -0,0 +1,103 @@
+;;; Copyright © 2023 Sam Lockart <sam@samlockart.com>
+;;; Copyright © 2023 Efraim Flashner <efraim@flashner.co.il>
+;;;
+;;; This file is an addendum to 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 (dfsg contrib services tailscale)
+  #:use-module (gnu services)
+  #:use-module (gnu services admin)
+  #:use-module (gnu services configuration)
+  #:use-module (gnu services shepherd)
+  #:use-module (guix records)
+  #:use-module (guix gexp)
+  #:use-module (dfsg contrib tailscale)
+  #:export (tailscaled-service-type
+            tailscaled-configuration))
+
+(define-record-type* <tailscaled-configuration>
+  tailscaled-configuration make-tailscaled-configuration
+  tailscaled-configuration?
+  (package      tailscaled-configuration-package
+                (default tailscale))   ; package
+  (listen-port  tailscaled-configuration-listen-port
+                (default 41641))     ; number
+  (state-file   tailscaled-configuration-state-file
+                (default "/var/lib/tailscale/tailscaled.state"))  ; path
+  (socket-file  tailscaled-configuration-socket-file
+                (default "/var/run/tailscale/tailscaled.sock"))   ; path
+  (no-logs?     tailscaled-configuration-no-logs
+                (default #f))
+  (dev-net-tun? tailscaled-configuration-dev-net-tun
+                (default #t))
+  (verbosity    tailscaled-configuration-verbosity
+                (default 0)))          ; number
+
+(define (tailscaled-activation config)
+  "Create the necessary directories for tailscale and run 'tailscaled
+--cleanup' at startup, as recommended."
+  (with-imported-modules '((guix build utils))
+    #~(begin
+        (use-modules (guix build utils))
+        (mkdir-p (dirname #$(tailscaled-configuration-state-file config)))
+        (mkdir-p (dirname #$(tailscaled-configuration-socket-file config)))
+        (system* #$(file-append (tailscaled-configuration-package config)
+                                "/sbin/tailscaled") "--cleanup"))))
+
+;; Can this service be limited to /var/lib/tailscale, /var/run/tailscale and /var/log?
+(define (tailscaled-shepherd-service config)
+  "Return a <shepherd-service> for Tailscaled with CONFIG"
+  (match-record config <tailscaled-configuration>
+                (package listen-port state-file socket-file no-logs? dev-net-tun? verbosity)
+    (list
+      (shepherd-service
+        (provision '(tailscaled))
+        (documentation "Tailscaled networking daemon")
+        (requirement '(networking))
+        (start #~(make-forkexec-constructor
+                   (list #$(file-append package "/sbin/tailscaled")
+                         #$@(if dev-net-tun?
+                              '()
+                              '("--tun=userspace-networking"))
+                         "-state" #$state-file
+                         "-socket" #$socket-file
+                         "-port" (number->string #$listen-port)
+                         #$@(if no-logs?
+                              '("-no-logs-no-support")
+                              '())
+                         "-verbose" (number->string #$verbosity))
+                   #:log-file "/var/log/tailscaled.log"))
+        (stop #~(make-kill-destructor))))))
+
+(define %tailscaled-log-rotation
+  (list (log-rotation
+          (files '("/var/log/tailscaled.log"))
+          (options `("rotate 4"
+                     ,@%default-log-rotation-options)))))
+
+(define tailscaled-service-type
+  (service-type
+    (name 'tailscaled)
+    (extensions
+      (list (service-extension shepherd-root-service-type
+                               tailscaled-shepherd-service)
+            (service-extension activation-service-type
+                               tailscaled-activation)
+            (service-extension rottlog-service-type
+                               (const %tailscaled-log-rotation))
+            (service-extension profile-service-type
+                               (compose list tailscaled-configuration-package))))
+    (default-value (tailscaled-configuration))
+    (description "Launch tailscaled.")))