Categories
Database Postgresql

Netbox: Running scripts on command line

It is possible to run scripts in netbox, both from the web GUI and also on the command line. However the usage is not very intuitive. so here’s a (very short) introduction. Basic knowledge First of all we need to know where to locate the scripts. That one is relatively easy: Place them into a […]

Categories
Database Postgresql

Convert postgres database dumps

Postgres can dump databases in 2 different formats: Both have their advantages and disadvantages. The later makes dumps better readable, so what can you do if your backup is using the first format? First let’s check the source format of our dump: Most online searches will result in: Restore the data to a new database […]

Categories
Container Docker Linux Network Ubuntu

Fixing Unifi network application insights error

This seems to apply to the docker version only, and maybe only to older ones that were installed some time ago. What happened Everytime I tried to access the “Insights” menu item on my docker hosted Unifi network application I got a short popup telling me “An error occured while trying to retreive logs” Further […]

Categories
Firewall Linux Network Ubuntu VPN Wireguard

Distributed fail2ban

Once you start to use fail2ban on more than one machine you’ll get to the point where you’d like to apply the IP blocking to machines other than the local one. While there are other (partially commercial) solutions to do that, I still decided to go with fail2ban. Please consider the following description as a […]

Categories
Linux Ubuntu

Diagnosing DNS resolver problems with systemd

As usual the first step is to find the right tools to start the debugging. For systemd systems (like my Ubuntu LTS 24.04) on helper is resolvectl: Hint: older systems may use systemd-resolve –status instead. Some words about my environment: Some of the settings listed above can be modified here: Quite naively I was expecting […]

Categories
Apache Filesystem Linux Ubuntu

fail2ban in depth

Skipping through my log files I found some concerning entries that were not covered by the existing fail2ban config. While trying to figure the correct regular expressions (regexp) to match these entries I had to take a close look at the things fail2ban provides to make things easier. Basic configuration As usual my test are […]

Categories
Cloud Linux Ubuntu

Open Cloud Mesh (OCM) in action

While trying to get my Nextcloud instance to talk to an OpenCloud Test instance I had to dig a little deeper into the unterlying protocol: Open Cloud Mesh (or short OCM, details s. RFC-draft). TL;DR: For everyone keen to get things up and running: I didn’t succeed (yet). And though I really like the idea […]

Categories
GPU Graphics Card Linux Ubuntu

Preparing AMD APUs for LLM usage

While investigating whether my AMD is somewhat usable for running LLMs I this is what I found. Preparations Installation of amdgpu driver and ROCm is explained here. Hardware/device information During reboot the amdgpu driver logs some information about the available amount of graphics memory: the reserved VRAM memory and the GTT (graphics translation table) memory […]

Categories
IdP Linux SAML Shibboleth Simplesamlphp SingleSignOn SSO

Debugging Shibboleth attribute mapping

I recently tried to clone an existing SSO-protected application to use a new IdP. The older instance was protected using SAML (keycloak based) and worked fine. Now the IdP changed to (a much larger) SimpleSAMLphp and while the login itself worked the application refused to work. Suspected culprit: attributes (missing, unmapped or mapped the wrong […]

Categories
Browser Debian IdP Keycloak LDAP Linux Nextcloud SAML Shibboleth SingleSignOn SSO Ubuntu

Nextcloud SAML and LDAP authentication

I’ve been running my nextcloud instance for quite some years now, and I finally decided to change its authentication from LDAP to SAML for a better single sign on experience. By using keycloak as IdP there’ll also be an option to enable multi factor authentication (MFA) for all connected applications at once. Where I come […]