Initial commit; enough to prove concepts at least

was able to bootstrap a complete machine with this, although there's lots
missing yet...

rattail_fabric2/postfix.py

@@ -0,0 +1,73 @@
+# -*- coding: utf-8; -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2018 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/>.
+#
+################################################################################
+"""
+Fabric library for Postfix
+"""
+
+from __future__ import unicode_literals, absolute_import
+
+from rattail_fabric2 import apt
+
+
+def install(c):
+    """
+    Install the Postfix mail service
+    """
+    apt.install(c, 'postfix')
+    apt.purge(c, 'exim4', 'exim4-base', 'exim4-config', 'exim4-daemon-light')
+
+
+def alias(c, name, alias_to, path='/etc/aliases'):
+    """
+    Set a mail alias for Postfix
+    """
+    # does alias entry already exist?
+    if c.run("grep '^{}:' /etc/aliases".format(name), warn=True).failed:
+        # append new entry
+        c.sudo("""bash -c 'echo "{}: {}" >> /etc/aliases'""".format(name, alias_to))
+    else:
+        # update existing entry
+        c.sudo('sed -i.bak -e "s/^{}: .*/{}: {}/" /etc/aliases'.format(name, name, alias_to))
+
+    c.sudo('newaliases')
+
+
+def restart(c):
+    """
+    Restart the Postfix mail service
+    """
+    c.sudo('systemctl restart postfix.service')
+
+
+def set_config(c, setting, value):
+    """
+    Configure the given setting with the given value.
+    """
+    c.sudo("postconf -e '{}={}'".format(setting, value))
+
+
+def set_relayhost(c, relayhost):
+    """
+    Configure the 'relayhost' setting with the given string
+    """
+    set_config(c, 'relayhost', relayhost)