[kde-community] Using software created by KDE and KDE-related communities/companies for KDE infrastructure

[Luca Beltrame]

Ben Cooksley wrote:

Hello,

> Half the issue is that Kolab is extremely complex software. If

Having installed Kolab for personal use (me + a few acquaintances) on a 
server, here's my take.

First of all, yes, it is a rather complex piece of software that is made up 
by several sub components. Some are provided by Kolab itself, others are 
third party, like the 389-DS LDAP server (I've been told it could work with 
openLDAP, though), the Cyrus-IMAPd mail server, Postfix, and others.

If I were to tell the account of when I made the first install, at the time 
Kolab 3.1 was released, I would say "screw it". There is a lot of stuff that 
broke or that was "magical" (the "setup-kolab" script used to set up the 
system), and Debian packages were short of worthless (tested in a VM, before 
I moved to CentOS 6).

In particular there was a severe lack of documentation and instructions, 
especially for multidomain usage (which wouldn't apply to KDE, I guess). 

Things way improved afterwards, though, in particular with the Kolab 3.3 
release. Non-Kolab Systems people (aka people from the community) started 
getting involved and now the situation with the packages (Debian included) 
is much better than before. The docs are also open to external modifications 
(pull requests on GitHub, a minor one even done by yours truly ;) and 
there's a clear upgrade path detailed for users of previous versions.

Likewise the involvement of community people also caused fixes to appear 
faster in the project's OBS instance, meaning they get propagated to "end 
users".

It's still a very complex beast (you'll need to have some knowledge of the 
components invovled) but much less than before. 

Now on the technicalities. Kolab requires LDAP to handle the user accounts 
and MySQL / MariaDB for other parts (like caching information, or what is 
needed by the Roundcube webmail). For content filtering it uses AmavisD + 
spamassassin and an additional (configurable) home grown solution, 
"Wallace". 

Aside LDAP, everything in Kolab is handled through IMAP: calendar and 
contacts use specific folders which are then handled by Kontact's own Kolab 
resource to provide calendars and addressbooks (and in later versions, even 
notes). The calendars and addressbooks are also exposed via WebDAV through 
the "iRony" component for interoperability. Kolab has also a file sharing 
solution called Chwala, but at least for my uses it is not worth it, and I 
would recommend something else.

The web interface is pretty featureful and has a nice theme, if you like Web 
mail, that is. Almost everything that can be done from a mail client can be 
done via webmail.

User and group configuration runs on a separate admin UI, which can also 
handle shared IMAP folders and various permissions. 

Kolab has also a very configurable "sender policy" to allow / reject 
outgoing mail basing on attributes found in the LDAP records. 

On the use... I run this on metal, but I'm guessing it could be run on LXC 
or Docker (there are caveats to both approaches). The web frontend used for 
user administration / webmail uses Apache, but I've made it work with nginx 
(there are guides in the documentation).

If you have a slow disk on your server, you will see a slow access to mail, 
as Cyrus files run with chattr +S. It is recommended to either have a fast 
disk (not something my el cheapo dedicated has) or a battery backed RAID (in 
that case you can do chattr -S). I'm not sure if this is just an issue with 
my own server or not.

Backups are usual business (I back up the Cyrus spool + the LDAP database + 
MySQL daily). 

As for the distro used... as I've said, Debian packaging has improved 
consistently, but the best approach is always CentOS / RHEL. 

Lastly, you can still customimze your setup after the "magic" done by Kolab: 
I've added support for openDKIM on my own and tweaked various bits of 
Postfix and amavisd. 

Feel free to ask more questions if need be.

-- 
Luca Beltrame - KDE Forums team
KDE Science supporter
GPG key ID: 6E1A4E79