The `default_vsz_limit` is the maximum amount of virtual memory that can be allocated. It should be set *reasonably high* to avoid allocation issues with larger mailboxes. We're setting it to 1/3 of the total available memory (physical mem + swap) to be sure.

See here for discussion:
- https://www.dovecot.org/list/dovecot/2012-August/137569.html
- https://www.dovecot.org/list/dovecot/2011-December/132455.html

SSH fail2ban jail is not enabled by default and so the jail does not load.

in order to correlate with the management interface.

pip<6.1 + setuptools>=34 have a problem with packages that
try to update setuptools during installation, like cryptography.
See https://github.com/pypa/pip/issues/4253. The Ubuntu 14.04
package versions are pip 1.5.4 and setuptools 3.3. When we
install cryptography under those versions, it tries to update
setuptools to version 34, which became available about 10 days
ago, and then pip gets permanently broken with errors like
"ImportError: No module named 'packaging'".

The easiest work-around on systems that aren't already broken is
to upgrade pip and setuptools individually before we install any
package that tries to update setuptools.

Also try to detect a broken system and forcibly remove setuptools
first before trying to install/upgrade pip.

fixes #1080, fixes #1081, fixes #1086
see #1083
see https://discourse.mailinabox.email/t/error-with-pip-and-python/1880
see https://discourse.mailinabox.email/t/error-installing-mib/1875

move the custom exclusive process code from utils.py into a new python package named exclusiveprocess

* Added an error message to handle exceptions when the setup script is trying to determine the latest Miab version

* Fixed issue with relative path for rsync relative names

Actually using the parsed URL `path` part, instead of doing a lousy split().
Renamed the `p` variable into something more sensible (`target`).

Fixes: #1019

* Added more verbose error messages upon rsync failures

fixes #1033

* Added command to test file listing

fixes #834

* Fix #1023 by changing ownership of roundcube DB after running migrations

* Set mode of roundcube sqlite database during setup

* Fix #1023 by changing ownership of roundcube DB after running migrations

* Set mode of roundcube sqlite database during setup

Additionally, add the spam report headers to all emails, in order to make it easier to debug false negatives.

* Update owncloud to 9.1.2

* Upgrade to ownCloud 9.1.2 from 9.1.1 would fail because the guid of 9.1.1 matched with the regex for the version of 8.x

* Added support for backup to a remote server using rsync

* updated web interface to get data from user
* added way to list files from server

It’s not using the “username” field of the yaml configuration
file to minimise the amount of patches needed. So the username
is actually sorted within the rsync URL.
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* Added ssh key generation upon installation for root user.
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* Removed stale blank lines, and fixed typo
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* fix backup-location lines, by switching it from id to class

* Various web UI fixes

- fixed user field being shadowed ;
- fixed settings reading comparaison ;
- fixed forgotten min-age field.
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* Added SSH Public Key shown on the web interface UI
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* trailing spaces.
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* fixed the extraneous environment
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* Updated key setup

- made key lower in bits, but stronger (using -a option),
- made ssh-keygen run in background using nohup,
- added independent key file, as id_rsa_miab,
- added ssh-options to all duplicity calls to use the id_rsa_miab keyfile,
- changed path to the public key display
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* added rsync options for ssh identity support
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* removed strict host checking for all backup operations
Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

* Remove nohup from ssh-keygen so errors aren't hidden. Also only generate a key if none exists yet

* Add trailing slash when checking a remote backup. Also check if we actually can read the remote size

* Factorisation of the repeated rsync/ssh options

cf https://github.com/mail-in-a-box/mailinabox/pull/678#discussion_r81478919

* Updated message SSH key creation

https://github.com/mail-in-a-box/mailinabox/pull/678#discussion_r81478886