When configuring and testing a Python Icinga plugin within an OMD site, I stumbled upon the following error recently:

1TypeError: 'frozenset' object is not callable

After some tests on other systems, I found out, that the Python library hashlib shipped with OMD seems to be faulty. Copying the system-wide …

Recently I had issues with configuring CardDAV-Sync and CalDAV-Sync along with Owncloud after a fresh Android installation. Specifying the well-known URLs just produced several error messages inside the app:

https://my-server.tld/owncloud/remote.php/caldav/principals/USER/ …

As preparation for a restore test, I removed the master boot record (MBR) of a Linux system recently:

1# dd if=/dev/zero of=/dev/sda bs=512 count=1

This command fills the first 512 bytes (containing the partition table and bootloader) of the first hard drive (/dev/sda) with zeroes (/dev/zero).

The problem is when you …

Sometimes it happens that you lock out yourself from your Linux system. In the worst case, additional security concepts or conditions might hamper access to the system, for example:

• No root access
• System cannot be rebooted to reset the password in a chroot session
• No colleague with system access available

Recently I …

Since 2008 I have been using the free Linux distribution IPCop to implement a customized firewall/a router. Of course, DSL providers also equip their customers with routers, but back then I was missing a couple of functions. To name some of them:

• IPSec / OpenVPN
• NTP time server
• DMZ segmentation
• WLAN access point with …

With the new major version 8, GitLab was extended to include a continuous integration (CI) component that was developed as dedicated project until now. While it was necessary to utilize external solutions, such as Jenkins, previously, it it now possible to automatically compile and test managed projects easily.

But, …

While registering a client system with a FreeIPA server I recently stumbled upon the following error message:

1# ipa-client-install
2...
3User authorized to enroll computers: admin
4...
5Kerberos authentication failed
6kinit: Cannot read password while getting initial credentials

After wasting quite a lot of time with …