Refactor MTA alias creation.

* Create an IMailTransportAgentAliases utility that contains all the logic for
  generating all the aliases for a mailing list, both the fully-qualified ones
  and the local-part ones.

* Add -f and -s options to `bin/mailman aliases` to facilitate outputing the
  aliases in other formats than the configured one, and for printing out a
  simple list of the aliases.

* IMailTransportAgentAliases -> IMailTransportAgentLifecycle; also add a new
  definition for IMailTransportAgentAliases

1 files changed, 61 insertions, 13 deletions

diff --git a/src/mailman/commands/docs/aliases.txt b/src/mailman/commands/docs/aliases.rst
index 0822ad973..c0d4c10c9 100644
--- a/src/mailman/commands/docs/aliases.txt
+++ b/src/mailman/commands/docs/aliases.rst
@@ -6,11 +6,12 @@ For some mail servers, Mailman must generate a data file that is used to hook
 Mailman up to the mail server.  The details of this differ for each mail
 server.  Generally these files are automatically kept up-to-date when mailing
 lists are created or removed, but you might occasionally need to manually
-regenerate the file.  The 'bin/mailman aliases' command does this.
+regenerate the file.  The ``bin/mailman aliases`` command does this.
 
     >>> class FakeArgs:
     ...     output = None
-
+    ...     format = None
+    ...     simple = None
     >>> from mailman.commands.cli_aliases import Aliases
     >>> command = Aliases()
 
@@ -32,19 +33,13 @@ generation.
 
 Let's create a mailing list and then display the transport map for it.  We'll
 send the output to stdout.
+::
 
     >>> FakeArgs.output = '-'
     >>> mlist = create_list('test@example.com')
     >>> command.process(FakeArgs)
     # AUTOMATICALLY GENERATED BY MAILMAN ON ...
-    #
-    # This file is generated by Mailman, and is kept in sync with the ...
-    # file.  YOU SHOULD NOT MANUALLY EDIT THIS FILE unless you know what you're
-    # doing, and can keep the two files properly in sync.  If you screw it up,
-    # you're on your own.
-    <BLANKLINE>
-    # Aliases which are visible only in the @example.com domain.
-    <BLANKLINE>
+    ...
     test@example.com               lmtp:[lmtp.example.com]:24
     test-bounces@example.com       lmtp:[lmtp.example.com]:24
     test-confirm@example.com       lmtp:[lmtp.example.com]:24
@@ -56,8 +51,61 @@ send the output to stdout.
     test-unsubscribe@example.com   lmtp:[lmtp.example.com]:24
     <BLANKLINE>
 
+    >>> config.pop('postfix')
 
-Clean up
-========
 
-    >>> config.pop('postfix')
+Alternative output
+==================
+
+By using a command line switch, we can select a different output format.  The
+option must point to an alternative implementation of the
+``IMailTransportAgentAliases`` interface.
+
+Mailman comes with an alternative implementation that just prints the aliases,
+with no adornment.
+
+    >>> FakeArgs.format = 'mailman.commands.cli_aliases.Dummy'
+    >>> command.process(FakeArgs)
+    test@example.com
+    test-bounces@example.com
+    test-confirm@example.com
+    test-join@example.com
+    test-leave@example.com
+    test-owner@example.com
+    test-request@example.com
+    test-subscribe@example.com
+    test-unsubscribe@example.com
+    <BLANKLINE>
+
+A simpler way of getting the same output is with the ``--simple`` flag.
+
+    >>> FakeArgs.format = None
+    >>> FakeArgs.simple = True
+    >>> command.process(FakeArgs)
+    test@example.com
+    test-bounces@example.com
+    test-confirm@example.com
+    test-join@example.com
+    test-leave@example.com
+    test-owner@example.com
+    test-request@example.com
+    test-subscribe@example.com
+    test-unsubscribe@example.com
+    <BLANKLINE>
+
+
+Mutually exclusive arguments
+============================
+
+You cannot use both ``--simple`` and ``--format``.
+
+    >>> FakeArgs.format = 'mailman.commands.cli_aliases.Dummy'
+    >>> FakeArgs.simple = True
+    >>> class Parser:
+    ...     def error(self, message):
+    ...         raise RuntimeError(message)
+    >>> command.parser = Parser()
+    >>> command.process(FakeArgs)
+    Traceback (most recent call last):
+    ...
+    RuntimeError: Cannot use both -s and -f