tests: Add vnstat tests.

* gnu/tests/vnstat.scm: New file.
* gnu/local.mk: Register it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/local.mk

@@ -796,6 +796,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/tests/version-control.scm			\
   %D%/tests/virtualization.scm			\
   %D%/tests/vnc.scm				\
+  %D%/tests/vnstat.scm				\
   %D%/tests/web.scm
 
 INSTALLER_MODULES =                             \

gnu/tests/vnstat.scm

@@ -0,0 +1,159 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2023 Bruno Victal <mirai@makinata.eu>.
+;;;
+;;; 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 tests vnstat)
+  #:use-module (gnu tests)
+  #:use-module ((gnu packages networking) #:select (socat vnstat))
+  #:use-module (gnu services)
+  #:use-module (gnu services networking)
+  #:use-module (gnu services monitoring)
+  #:use-module (gnu system)
+  #:use-module (gnu system vm)
+  #:use-module (guix gexp)
+  #:use-module (ice-9 format)
+  #:export (%test-vnstat))
+
+
+(define (run-vnstat-test)
+  "Run tests in a vm which has vnstat running."
+
+  (define vnstat-config
+    (vnstat-configuration
+     (max-bandwidth 0)
+     (time-sync-wait 0)
+     (bandwidth-detection-interval 0)))
+
+  (define inetd-service-entry-config
+    (inetd-entry
+     (name "discard")
+     (socket-type 'stream)
+     (protocol "tcp")
+     (wait? #t)
+     (user "nobody")))
+
+  (define os
+    (marionette-operating-system
+     (simple-operating-system
+      (service dhcp-client-service-type)
+      (service vnstat-service-type
+               vnstat-config)
+      (service inetd-service-type
+               (inetd-configuration
+                (entries
+                 (list inetd-service-entry-config)))))
+     #:imported-modules '((gnu services herd))))
+
+  (define forwarded-port 9999)
+
+  (define vm
+    (let* ((inetd-service-name "discard")
+           (inetd-service-proto
+            (inetd-entry-protocol inetd-service-entry-config))
+           (guest-port
+            (servent:port (getservbyname inetd-service-name
+                                         inetd-service-proto))))
+      (virtual-machine
+       (operating-system os)
+       (port-forwardings `((,forwarded-port . ,guest-port))))))
+
+  ;; The test duration is inconsistent, at times a test may complete under
+  ;; 2 minutes and at times it may take up to 5 minutes.
+  (define test-timeout (* 60 5))
+
+  (define test
+    (with-imported-modules '((gnu build marionette))
+      #~(begin
+          (use-modules (gnu build marionette)
+                       (srfi srfi-64))
+
+          (let ((marionette (make-marionette (list #$vm)))
+                (pid-file #$(vnstat-configuration-pid-file vnstat-config)))
+
+            (test-runner-current (system-test-runner #$output))
+            (test-begin "vnstat")
+
+            (test-assert "service is running"
+              (marionette-eval
+               '(begin
+                  (use-modules (gnu services herd))
+                  (start-service 'vnstatd))
+               marionette))
+
+            (test-assert "vnstatd ready"
+              (wait-for-file pid-file marionette))
+
+            ;; Pump garbage into the 'discard' inetd service within the vm.
+            (let* ((socat #$(file-append socat "/bin/socat"))
+                   (dest-addr #$(format #f "TCP4:localhost:~d"
+                                        forwarded-port))
+                   (args `("socat" "-u" "/dev/zero" ,dest-addr))
+                   ;; XXX: Guile bug (22/03/2023, Guile 3.0.9)
+                   ;; Fixed in main: <https://issues.guix.gnu.org/61073>
+                   ;; FIXME: re-add #:output (%make-void-port "w") below on
+                   ;; next Guile release.
+                   (garbage-pump-pid
+                    (spawn socat args)))
+              (test-group-with-cleanup "Logging"
+                ;; To aid debugging, this test returns #t on success
+                ;; and either #f or 'timed-out otherwise.
+                (test-eq "vnstatd is logging"
+                  #t
+                  (marionette-eval
+                   '(begin
+                      (use-modules (ice-9 popen)
+                                   (ice-9 match)
+                                   (sxml simple)
+                                   (sxml xpath))
+
+                      (define selector
+                        (let ((xpath '(vnstat interface traffic total)))
+                          (compose (node-pos 1) (sxpath xpath))))
+
+                      (let loop ((i 0))
+                        (let* ((vnstat #$(file-append vnstat "/bin/vnstat"))
+                               (query-cmd (format #f "~a --xml" vnstat))
+                               (proc (compose selector xml->sxml))
+                               (result
+                                (call-with-port
+                                    (open-input-pipe query-cmd) proc)))
+                          (match result
+                            ;; Counter still warming up.
+                            ((('total ('rx "0") ('tx "0")))
+                             (sleep 1)
+                             (if (< i #$test-timeout)
+                                 (loop (+ i 1))
+                                 'timed-out))
+                            ;; Count of bytes on iface was non-zero.
+                            ((('total ('rx rx) ('tx tx)))
+                             #t)
+                            ;; Unknown data encountered, perhaps the
+                            ;; data format changed?
+                            (_ #f)))))
+                   marionette))
+                ;; Cleanup: shutdown garbage pump.
+                (kill garbage-pump-pid SIGTERM)))
+
+            (test-end)))))
+
+  (gexp->derivation "vnstat-test" test))
+
+(define %test-vnstat
+  (system-test
+   (name "vnstat")
+   (description "Basic tests for vnstat service.")
+   (value (run-vnstat-test))))