Add basic rattail postfix-summary command

hopefully will help track down mail problems when they occur.  note
that this may require configuring `sudoers` to work correctly

rattail/commands/postfix.py

@@ -0,0 +1,100 @@
+# -*- coding: utf-8; -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2022 Lance Edgar
+#
+#  This file is part of Rattail.
+#
+#  Rattail 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.
+#
+#  Rattail 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
+#  Rattail.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+"""
+Commands relating to Postfix
+"""
+
+from __future__ import unicode_literals, absolute_import
+
+import re
+import sys
+import subprocess
+import logging
+
+import six
+
+from rattail.commands.core import Subcommand
+
+
+log = logging.getLogger(__name__)
+
+
+class PostfixSummary(Subcommand):
+    """
+    Generate (and maybe email) a Postfix log summary
+    """
+    name = 'postfix-summary'
+    description = __doc__.strip()
+
+    def add_parser_args(self, parser):
+
+        parser.add_argument('--email', action='store_true', default=False,
+                            help="Email the summary instead of displaying it.")
+
+        parser.add_argument('--problems-only', action='store_true',
+                            help="Only show summary if it contains problems.")
+
+        parser.add_argument('--yesterday', action='store_true',
+                            help="Show summary for previous day only.")
+
+        parser.add_argument('file', nargs='*', default=['/var/log/mail.log'],
+                            help="Path(s) to mail log file(s)")
+
+    def run(self, args):
+
+        # TODO: any way to get around using 'sudo' here?
+        cmd = ['sudo', 'pflogsumm', '--problems-first']
+        if args.yesterday:
+            cmd.extend(['-d', 'yesterday'])
+        cmd.extend(args.file)
+
+        # run cmd
+        output = subprocess.check_output(cmd).decode('utf_8')
+
+        # parse problem counts
+        problems = {}
+        pattern = re.compile(r'^ +(\d)   (deferred|bounced|rejected|reject warnings|held|discarded)\b')
+        for line in output.split('\n'):
+            match = pattern.match(line)
+            if match:
+                problem = match.group(2)
+                if problem in problems:
+                    log.warning("extra line matches '%s' pattern: %s", problem, line)
+                problems[problem] = int(match.group(1))
+
+        log.info("postfix summary contained %s problems",
+                 sum(six.itervalues(problems)))
+
+        # bail if caller only wants to see problems and we have none
+        if args.problems_only:
+            if not any(six.itervalues(problems)):
+                return
+
+        # just display the summary unless we're to email it
+        if args.email:
+            self.app.send_email('postfix_summary', {
+                'output': output,
+                'problems': problems,
+            })
+        else:
+            self.stdout.write(output)

rattail/emails.py

@@ -185,6 +185,18 @@ class new_phone_requested(Email):
         }
 
 
+class postfix_summary(Email):
+    """
+    Sends a summary of Postfix mail activity.
+    """
+    default_subject = "Postfix Summary"
+
+    def sample_data(self, request):
+        return {
+            'output': "(pflogsumm output goes here)",
+        }
+
+
 class ImporterEmail(Email):
     """
     Sent when a "version catch-up" import is performed, which involves changes.

rattail/templates/mail/postfix_summary.txt.mako

@@ -0,0 +1,2 @@
+## -*- coding: utf-8; -*-
+${output}

setup.py

@@ -229,6 +229,7 @@ setup(
             'refresh-batch = rattail.commands.batch:RefreshBatch',
             'run-n-mail = rattail.commands.core:RunAndMail',
             'runsql = rattail.commands.core:RunSQL',
+            'postfix-summary = rattail.commands.postfix:PostfixSummary',
             'setting-get = rattail.commands.settings:SettingGet',
             'setting-put = rattail.commands.settings:SettingPut',
             'update-costs = rattail.commands.products:UpdateCosts',