tests: mail: Add test for exim

* gnu/tests/mail.scm (%exim-os, %test-exim): New variables.
(run-exim-test): New procedure.

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

gnu/tests/mail.scm

@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2016 Sou Bunnbu <iyzsong@member.fsf.org>
+;;; Copyright © 2017 Carlo Zancanaro <carlo@zancanaro.id.au>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -26,7 +27,9 @@
   #:use-module (guix gexp)
   #:use-module (guix monads)
   #:use-module (guix store)
-  #:export (%test-opensmtpd))
+  #:use-module (ice-9 ftw)
+  #:export (%test-opensmtpd
+            %test-exim))
 
 (define %opensmtpd-os
   (simple-operating-system
@@ -146,3 +149,133 @@ accept from any for local deliver to mbox
    (name "opensmtpd")
    (description "Send an email to a running OpenSMTPD server.")
    (value (run-opensmtpd-test))))
+
+
+(define %exim-os
+  (simple-operating-system
+   (dhcp-client-service)
+   (service mail-aliases-service-type '())
+   (service exim-service-type
+            (exim-configuration
+             (config-file
+              (plain-file "exim.conf" "
+primary_hostname = komputilo
+domainlist local_domains = @
+domainlist relay_to_domains =
+hostlist   relay_from_hosts = localhost
+
+never_users =
+
+acl_smtp_rcpt = acl_check_rcpt
+acl_smtp_data = acl_check_data
+
+begin acl
+
+acl_check_rcpt:
+  accept
+acl_check_data:
+  accept
+"))))))
+
+(define (run-exim-test)
+  "Return a test of an OS running an Exim service."
+  (mlet* %store-monad ((command (system-qemu-image/shared-store-script
+                                 (marionette-operating-system
+                                  %exim-os
+                                  #:imported-modules '((gnu services herd)))
+                                 #:graphic? #f)))
+    (define test
+      (with-imported-modules '((gnu build marionette)
+                               (ice-9 ftw))
+        #~(begin
+            (use-modules (rnrs base)
+                         (srfi srfi-64)
+                         (ice-9 ftw)
+                         (ice-9 rdelim)
+                         (ice-9 regex)
+                         (gnu build marionette))
+
+            (define marionette
+              (make-marionette
+               ;; Enable TCP forwarding of the guest's port 25.
+               '(#$command "-net" "user,hostfwd=tcp::1025-:25")))
+
+            (define (read-reply-code port)
+              "Read a SMTP reply from PORT and return its reply code."
+              (let* ((line      (read-line port))
+                     (mo        (string-match "([0-9]+)([ -]).*" line))
+                     (code      (string->number (match:substring mo 1)))
+                     (finished? (string= " " (match:substring mo 2))))
+                (if finished?
+                    code
+                    (read-reply-code port))))
+
+            (define smtp (socket AF_INET SOCK_STREAM 0))
+            (define addr (make-socket-address AF_INET INADDR_LOOPBACK 1025))
+
+            (mkdir #$output)
+            (chdir #$output)
+
+            (test-begin "exim")
+
+            (test-assert "service is running"
+              (marionette-eval
+               '(begin
+                  (use-modules (gnu services herd))
+                  (start-service 'exim)
+                  #t)
+               marionette))
+
+            (sleep 1) ;; give the service time to start talking
+
+            (connect smtp addr)
+            ;; Be greeted.
+            (test-eq "greeting received"
+              220 (read-reply-code smtp))
+            ;; Greet the server.
+            (write-line "EHLO somehost" smtp)
+            (test-eq "greeting successful"
+              250 (read-reply-code smtp))
+            ;; Set sender email.
+            (write-line "MAIL FROM: test@example.com" smtp)
+            (test-eq "sender set"
+              250 (read-reply-code smtp)) ;250
+            ;; Set recipient email.
+            (write-line "RCPT TO: root@komputilo" smtp)
+            (test-eq "recipient set"
+              250 (read-reply-code smtp)) ;250
+            ;; Send message.
+            (write-line "DATA" smtp)
+            (test-eq "data begun"
+              354 (read-reply-code smtp)) ;354
+            (write-line "Subject: Hello" smtp)
+            (newline smtp)
+            (write-line "Nice to meet you!" smtp)
+            (write-line "." smtp)
+            (test-eq "message sent"
+              250 (read-reply-code smtp)) ;250
+            ;; Say goodbye.
+            (write-line "QUIT" smtp)
+            (test-eq "quit successful"
+              221 (read-reply-code smtp)) ;221
+            (close smtp)
+
+            (test-eq "the email is received"
+              1
+              (marionette-eval
+               '(begin
+                  (use-modules (ice-9 ftw))
+                  (length (scandir "/var/spool/exim/msglog"
+                                   (lambda (x) (not (string-prefix? "." x))))))
+               marionette))
+
+            (test-end)
+            (exit (= (test-runner-fail-count (test-runner-current)) 0)))))
+
+    (gexp->derivation "exim-test" test)))
+
+(define %test-exim
+  (system-test
+   (name "exim")
+   (description "Send an email to a running an Exim server.")
+   (value (run-exim-test))))