cyrusutils

Cyrus imap mailbox migration utilities

Uses:

Cyrus Imapd Skiplist db recovery tool
Copyright (C) 2004-2006 Gianluigi Tiesi <sherpya@netfarm.it>
Copyright (C) 2004-2006 NetFarm S.r.l.  [http://www.netfarm.it]

Cyruslib v0.8.5-20090401
Copyright (C) 2007-2009 Reinaldo de Carvalho <reinaldoc@gmail.com>
Copyright (C) 2003-2006 Gianluigi Tiesi <sherpya@netfarm.it>
Copyright (C) 2003-2006 NetFarm S.r.l. [http://www.netfarm.it]

About

This utility migrates cyrus imap mailboxes from one format to another. The following types are supported:

• local user mailbox
• virtual user mailbox (domain)
• shared mailboxes (both local and virtual)
• "offline" mailboxes, exist on filesystem but are not known to cyrus-imap

cyrusmigrate will convert the mailboxes, the .seen and .sub files. I do not use quotas so these are not converted.

I wrote this utility because I was changing host providers where I run my small mailserver for a bunch of accounts (<50), and at the same time I wanted to change the type of account from local users to virtual users. The mailserver hosts a variety of different domains and it made sense to partition all users into their respective domains. So instead of users authenticating with usernames "bobj" and "bobw", they would use "bob@example.com" and "bob@other.com".

Doing the migration whilst maintaining a service is a challenge, so I needed a utility that would automate the migration for me that could be run and re-run until the final DNS switch was made.

There are two basic ways to use this utility

• to migrate an active account to another active
• to migrate an inactive account from the filesystem to an active account ("rootPath" option)

The latter is used if you want to take a backup of an existing mailserver and create a new one. This is the approach I took, where I used rsync to mirror all files under /var/spool/imap and /var/lib/imap to a temporary file root, say /old.

This way I could run rsync frequently to ensure I had all the latest mailbox files, and then use cyrusmigrate on the rsync'd folder to populate the new mailboxes.

Syncing old mailboxes to new host

The following rsync command (in python) will pull over all relevant files from oldmailhost onto the current host. Because I was migrating from local user to virtual user , I just needed the mailbox files from /var/spool/imap and the metadata files from /var/lib/imap/user

 import subprocess
 subprocess.check_call([
    'rsync',
    '--verbose',
    '--archive',
    '--compress',
    '--relative',
    '--delete',
    '--exclude=cyrus.*',
    'oldmailhost:/var/spool/imap',
    'oldmailhost:/var/lib/imap/user',
    '/'
  ])

If you are using the rootPath option then you only need the cyrus.header files

import subprocess
subprocess.check_call([
  'rsync',
  '--verbose',
  '--archive',
  '--compress',
  '--relative',
  '--delete',
  '--include=cyrus.header',
  '--exclude=stage.',
  '--exclude=cyrus.*',
  'oldmailhost:/var/spool/imap',
  'oldmailhost:/var/lib/imap/user',
  '/old'
])

Next, the CyrusMigrate utility is called for each account to migrate

imap = cyruslib.CYRUS("imaps://localhost:993")
imap.login('cyrus', 'password')

migration = CyrusMigrate(imap, olduser, newuser, rootPath='/old', verbose=True)
migration()