deliver-email: Send email data to program

Allow a "sendmail" program to be configured. If set, `deliver-email`
will spawn the program and write the email its standard input.

We can thus send the email by invoking the external program.

3 files changed, 17 insertions, 2 deletions

diff --git a/src/config.lisp b/src/config.lisp
index 0bc6fee..b1093b6 100644
--- a/src/config.lisp
+++ b/src/config.lisp
@@ -14,6 +14,11 @@
      :reader endpoint
      :documentation "Jira site URL (e.g. example.atlassian.net)")
 
+   (sendmail
+     :initarg :sendmail
+     :reader sendmail
+     :documentation "Email sending client command")
+
    (email-to
      :initarg :email-to
      :reader email-to
diff --git a/src/email.lisp b/src/email.lisp
index 9e5929c..fe80af1 100644
--- a/src/email.lisp
+++ b/src/email.lisp
@@ -1,8 +1,17 @@
 (in-package :wajir)
 
 (defun deliver-email (config issue)
+  (let ((message (with-output-to-string (message-stream)
+                   (build-email config issue message-stream))))
+
+    (with-open-stream (sendmail-input (make-string-input-stream message))
+      (uiop:run-program (sendmail config)
+                        :output "/tmp/wajir.output"
+                        :input sendmail-input))))
+
+(defun build-email (config issue output-stream)
   (cl-smtp:write-rfc8822-message
-    *standard-output*
+    output-stream
     (format nil "wajir@~A" (uiop:hostname))
     `(,(email-to config))
     (format-subject issue)
diff --git a/src/main.lisp b/src/main.lisp
index 7c0f368..d700182 100644
--- a/src/main.lisp
+++ b/src/main.lisp
@@ -84,4 +84,5 @@
   ;; 2. Send email
   (format t "Watching issue ~A~%" (gethash "key" issue))
 
-  (deliver-email config issue))
+  (if (sendmail config)
+      (deliver-email config issue)))