Factor out email sending to utils

Smooth out some issues when --email isn't specified, making args.email
an empty list rather than None, which can't be iterated.

When the To: address is 'debug', dump email to log, rather than stdout.

3 files changed, 49 insertions, 35 deletions

diff --git a/calm/buffering_smtp_handler.py b/calm/buffering_smtp_handler.py
index f6d5f34..d0a8119 100644
--- a/calm/buffering_smtp_handler.py
+++ b/calm/buffering_smtp_handler.py
@@ -21,13 +21,11 @@
 #
 
 
-import email.message
-import email.utils
 import logging
 import logging.handlers
-import subprocess
 
 from . import common_constants
+from . import utils
 
 
 class BufferingSMTPHandler(logging.handlers.BufferingHandler):
@@ -60,37 +58,15 @@ class BufferingSMTPHandler(logging.handlers.BufferingHandler):
 
             msg = msg + 'SUMMARY: ' + ', '.join(['%d %s(s)' % (v, k) for (k, v) in summary.items()]) + "\r\n"
 
-            # build the email
-            m = email.message.Message()
-            m['From'] = self.fromaddr
-            m['To'] = ','.join(self.toaddrs)
-            m['Reply-To'] = self.replytoaddr
-            m['Bcc'] = common_constants.ALWAYS_BCC
-            m['Subject'] = self.subject
-            m['Message-Id'] = email.utils.make_msgid()
-            m['Date'] = email.utils.formatdate()
-            m['X-Calm'] = '1'
-
-            # use utf-8 only if the message can't be ascii encoded
-            charset = 'ascii'
-            try:
-                msg.encode('ascii')
-            except UnicodeError:
-                charset = 'utf-8'
-            m.set_payload(msg, charset=charset)
-
-            # if toaddrs consists of the single address 'debug', just dump the mail we would have sent
-            if self.toaddrs == ['debug']:
-                print('-' * 40)
-                for k in m:
-                    print('%s: %s' % (k, m[k]))
-                print('-' * 40)
-                print(msg)
-                print('-' * 40)
-            else:
-                with subprocess.Popen(['/usr/sbin/sendmail', '-t', '-oi', '-f', self.fromaddr], stdin=subprocess.PIPE) as p:
-                    p.communicate(m.as_bytes())
-                    logging.debug('sendmail: msgid %s, exit status %d' % (m['Message-Id'], p.returncode))
+            hdr = {}
+            hdr['From'] = self.fromaddr
+            hdr['To'] = ','.join(self.toaddrs)
+            hdr['Reply-To'] = self.replytoaddr
+            hdr['Bcc'] = common_constants.ALWAYS_BCC
+            hdr['Subject'] = self.subject
+            hdr['X-Calm-Report'] = '1'
+
+            utils.sendmail(hdr, msg)
 
             self.buffer = []
 
diff --git a/calm/calm.py b/calm/calm.py
index 7ea4739..a839873 100755
--- a/calm/calm.py
+++ b/calm/calm.py
@@ -754,7 +754,7 @@ def main():
 
     parser = argparse.ArgumentParser(description='Upset replacement')
     parser.add_argument('-d', '--daemon', action='store', nargs='?', const=pidfile_default, help="daemonize (PIDFILE defaults to " + pidfile_default + ")", metavar='PIDFILE')
-    parser.add_argument('--email', action='store', dest='email', nargs='?', const=common_constants.EMAILS, help="email output to maintainer and ADDRS (ADDRS defaults to '" + common_constants.EMAILS + "')", metavar='ADDRS')
+    parser.add_argument('--email', action='store', dest='email', nargs='?', default='', const=common_constants.EMAILS, help="email output to maintainer and ADDRS (ADDRS defaults to '" + common_constants.EMAILS + "')", metavar='ADDRS')
     parser.add_argument('--force', action='count', help="force regeneration of static htdocs content", default=0)
     parser.add_argument('--homedir', action='store', metavar='DIR', help="maintainer home directory (default: " + homedir_default + ")", default=homedir_default)
     parser.add_argument('--htdocs', action='store', metavar='DIR', help="htdocs output directory (default: " + htdocs_default + ")", default=htdocs_default)
diff --git a/calm/utils.py b/calm/utils.py
index 9f75813..47085fd 100644
--- a/calm/utils.py
+++ b/calm/utils.py
@@ -25,6 +25,8 @@
 # utility functions
 #
 
+import email.message
+import email.utils
 import filecmp
 import logging
 import os
@@ -158,3 +160,39 @@ def mtime_cache(user_function):
         return result
 
     return wrapper
+
+
+def sendmail(hdr, msg):
+    # sending email not enabled
+    if not hdr['To']:
+        return
+
+    # build the email
+    m = email.message.Message()
+
+    for h in hdr:
+        m[h] = hdr[h]
+    m['Message-Id'] = email.utils.make_msgid()
+    m['Date'] = email.utils.formatdate()
+    m['X-Calm'] = '1'
+
+    # use utf-8 only if the message can't be ascii encoded
+    charset = 'ascii'
+    try:
+        msg.encode('ascii')
+    except UnicodeError:
+        charset = 'utf-8'
+    m.set_payload(msg, charset=charset)
+
+    # if To: header consists of the single address 'debug', just dump the mail we would have sent
+    if m['To'] == 'debug':
+        logging.debug('-' * 40)
+        for k in m:
+            logging.debug('%s: %s' % (k, m[k]))
+        logging.debug('-' * 40)
+        logging.debug(msg)
+        logging.debug('-' * 40)
+    else:
+        with subprocess.Popen(['/usr/sbin/sendmail', '-t', '-oi', '-f', hdr['From']], stdin=subprocess.PIPE) as p:
+            p.communicate(m.as_bytes())
+            logging.debug('sendmail: msgid %s, exit status %d' % (m['Message-Id'], p.returncode))