This article describes the installation procedure for Kolab 16 on Debian 9 (Stretch).

Install the Aptitude package management tool

# apt-get install aptitude

Install the APT plugin for HTTPS transport

# aptitude -y install apt-transport-https

Configure the Kolab Software Repositories

Add the following two lines to /etc/apt/sources.list.d/kolab.list:

deb https://mirror.kolabenterprise.com/debian/kolab-16/ stretch release updates
deb-src https://mirror.kolabenterprise.com/debian/kolab-16/ stretch release updates

Set the Repository Priority

To ensure the Kolab packages have priority over the Debian packages, such as must be the case for PHP as well as Cyrus IMAP, please make sure the APT preferences pin the mirror.kolabsys.com origin as a preferred source.

Put the following in /etc/apt/preferences.d/kolab:

Package: *
Pin: origin mirror.kolabenterprise.com
Pin-Priority: 501

Install the GPG Signature

Install the public key used to sign the repository metadata with:

# wget -q -O- https://ssl.kolabsys.com/stretch.asc | apt-key add -

Install Kolab

Update the repository metadata:

# apt-get update

Start the installation of the base package as follows:

# aptitude install kolab

When asked to confirm you want to install the package and its dependencies, press Enter.

During the installation you will get asked which Postfix standard configuration to be used. Select:

No Configuration

Postfix will be configured by the setup-kolab script.

Aptitude will try to configure 389 LDAP server before it is started. This will result in error messages in the end of the install like these:

● dirsrv-admin.service - 389 Administration Server.
Loaded: loaded (/lib/systemd/system/dirsrv-admin.service; disabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Fri 2018-08-17 09:14:00 CEST; 6ms ago
Process: 30443 ExecStart=/usr/sbin/apache2 -k start -f /etc/dirsrv/admin-serv/httpd.conf (code=exited, status=1/FAILURE)

This is acceptable, as 389 LDAP server will be started and configured by the setup-kolab script.

Next steps

Run the setup-kolab script as described in this article.