My personal blog about tech stuff
As I am working with different technologies everyday, there is no specific focus on a tooling or technology in this blog, but rather sharing stuff which are - in my opinion - interesting for others as well.
Troubleshooting networking issues in docker and kubernetes is often difficult and the root cause can be in different places including the underlying networking infrastructure. I have collected some information which might be helpful.
Posted November 21, 2021 by Adrian Wyssmann ‐ 2 min read
After our kubernetes cluster was fine for some weeks, one of our nodes was suddenly unavailable due to permanently restarting rancher-agent
Posted October 22, 2021 by Adrian Wyssmann ‐ 4 min read
For some reason I got a free version of PCTipp, a Swiss PC magazine. Within the last issue, I found a promoted article about Hosttech GmbH, which now offers a virtual datacenter. Interesting enough for me to register and try it out.
Posted September 28, 2021 by Adrian Wyssmann ‐ 3 min read
As I am currently working on refreshing my networking skills and as I want to get deeper into network security, I was looking for some courses. As part of this research, I stumbled over GNS3 and CLM, both tools to create virtual lab environments.
Posted September 26, 2021 by Adrian Wyssmann ‐ 6 min read
Often pen-tester/security expert/hacker use Kali Linux or Parrot as their distro of choice. While they are great, I use Archlinux as my daily driver. Thus I want to have the same toolset as these distros installed and configured on my Archlinux
Posted September 19, 2021 by Adrian Wyssmann ‐ 2 min read
Working with java applications in kubernetes, you might come use
Posted September 9, 2021 by Adrian Wyssmann ‐ 2 min read
Installing and configuring logging with Rancher is quite easy, but in combination with Splunk some guidance might be helpful. I guide you trough the process of the complete installation and configuration
Posted September 9, 2021 by Adrian Wyssmann ‐ 5 min read
Installing monitoring and configuration with Rancher is quite easy, but in combination wit alerting for MS Teams some guidance might be helpful. I guide you trough the process of the complete installation and configuration
Posted September 9, 2021 by Adrian Wyssmann ‐ 5 min read
We manage our baremetal kubernetes nodes with salt and for security purposes, there is no direct ssh access. The only way to access them is using salt-master. This can be challenging if you want to get some files from the nodes, but it's possible.
Posted September 8, 2021 by Adrian Wyssmann ‐ 3 min read
Kubernetes is complex and at first overwhelming if you never did something with it. In this post I want to focus on a simple deployment and putting some pieces (Pod, Deployment, ConfigMap, Ingress) together to get a better understanding for newbies.
Posted August 17, 2021 by Adrian Wyssmann ‐ 4 min read
As we don't have an automated certificate management 😭 we have to create certificates and Certificate signing request manually. If you are in the same boat, this information might help you.
Posted August 15, 2021 by Adrian Wyssmann ‐ 2 min read
While we are using Rancher 2.5.x our current cluster management solution, we actually still are using the old istio- and monitoring-stack v1 rather than v2. We want to change that but it is not as easy as we thought.
Posted August 5, 2021 by Adrian Wyssmann ‐ 4 min read
Packet filtering is essential for network security and Linux offers this out of the box. There are different possibilities like iptables, nftables or firewalld, and a basic understanding of these is very useful.
Posted July 9, 2021 by Adrian Wyssmann ‐ 8 min read
While modern companies may use a pure cloud approach, there are still companies which still have their own datacenter. Thus connecting your on-premiss network to the cloud is essential. In this post, I will have a look on how this works and what is required, focusing on Azure, as this is what we currently use at my employer.
Posted July 7, 2021 by Adrian Wyssmann ‐ 1 min read
Not everybody can afford a study at an university, either cause you cannot afford it or you have other obstacles e.g a mother or father taking care of children. However, this should not stop you to study what you like. There are some nice collections of resources that allow you to study informatics, programming and sw engineering for free.
Posted June 5, 2021 by Adrian Wyssmann ‐ 2 min read
Last Wednesday I was attending the DevOps Connect: DevSecOps at RSAC 2021, whereas a cool project was presented: Crowdsec, a collaborative behavior detection engine, coupled with a global IP reputation network
Posted May 22, 2021 by Adrian Wyssmann ‐ 11 min read
At my current employer we use a container security platform called Stackrox, which recently was acquired by RedHat. But that is it exactly and for what is it good?
Posted May 17, 2021 by Adrian Wyssmann ‐ 6 min read
Since I last used packer it's been a while and when I recently wanted to create a new Windows vm, I used my project. This is where I realized certain things have changed with packer since I started the project.
Posted May 13, 2021 by Adrian Wyssmann ‐ 2 min read
During the years, I tried different services. Some of them offer offered free tiers/plans for developers or small teams. So I thought it would make sense to create a list, which can be easily shared with others.
Posted May 12, 2021 by Adrian Wyssmann ‐ 1 min read
Writing technical blogs often requires to do screenshot, where you may also want to highlight stuff of even obsfucate sensitive data.
Posted May 5, 2021 by Adrian Wyssmann ‐ 2 min read
If you have servers you definitively want to collect logs in a central place and store them for some time, so you can investigate what happens in case of issues. I personally rely on logz.io, but Grafana Cloud looks like a promising alternative
Posted May 3, 2021 by Adrian Wyssmann ‐ 5 min read
As a developer you are familiar with the terms continuous integration (CI) and continuous deployment (CD), which is often referred as CI/CD. However it's important to understand that these are different processes with different purposes.
Posted April 30, 2021 by Adrian Wyssmann ‐ 5 min read
I finally found some tome to improve my cloudflared ansible role, to be abel to use named tunnels
Posted April 25, 2021 by Adrian Wyssmann ‐ 1 min read
If you are running a bare-metal cluster you probably run kubernetes on top of some linux os, these systems have to be regularly updated. But an update means sometimes that you have to reboot your servers. This also means during a reboot that particular node is node available to schedule workload.
Posted April 20, 2021 by Adrian Wyssmann ‐ 6 min read
When you manage Linux systems it's usually pretty clear how to reboot a system. But do you know how to check whether a system requires a reboot? Cause you don't want to reboot a system if it is not necessary
Posted April 20, 2021 by Adrian Wyssmann ‐ 2 min read
In Hetzner Cloud you can have multiple projects. As you can have different members per group, it really makes sense to have different projects for different purposes. I will explain in this article on how I work with multiple projects in Ansible, as well when using the cli
Posted April 16, 2021 by Adrian Wyssmann ‐ 3 min read
Passing simple strings to an ansible playbook as extra-vars is easy, but what if you want to pass lists or dictionary? Let's see...
Posted April 16, 2021 by Adrian Wyssmann ‐ 4 min read
I recently struggled into an issue where I have certain tasks which I want to run for the bootstrapping, as well when applying the desired state. I don't want to have to repeat the same task in different playbooks, so I had a look into reusable of ansible elements
Posted April 15, 2021 by Adrian Wyssmann ‐ 4 min read
I use Hetzner Servers and Hetzner Cloud for my own infrastructure which I setup with Ansible since the beginning. It's usually not much servers so overseeable. However, maintaining static inventory for my ansible project is a bit cumbersome when you already have all information available in the management interface. So let's see what we can do about and how I can reduce manual overhead.
Posted April 8, 2021 by Adrian Wyssmann ‐ 6 min read
Posted March 25, 2021 by Adrian Wyssmann ‐ 1 min read
Here I want to explain why and how I engineered a vulnerability Waiver Process for infected 3rd party libraries.
Posted March 18, 2021 by Adrian Wyssmann ‐ 9 min read
My son has a Surface Go Tablet which suddenly stopped booting. Even after trying to uninstall patches etc. I could not bring it back, so I decided to help him to get the data from the tablet, so he can use it.
Posted March 13, 2021 by Adrian Wyssmann ‐ 3 min read
Maven release plugin does a great job incrasing the version in maven builds. Still sometimes you may need an alternative.
Posted March 3, 2021 by Adrian Wyssmann ‐ 3 min read
Jenkins is a very popular ci solution and offer a lot of extensibility by plugins. However, updating these plugins while you are sitting behind a corporate firewall. I explain you what is the issue and how we solve it.
Posted May 20, 2020 by Adrian Wyssmann ‐ 3 min read
I guess working in sw development we all know Jenkins and the ones how have to maintain it, knows the pain it can cause. Still, even if there are (better) alternatives, Jenkins may still be the first choice for a lot of companies. I would like to share here some things, which helps to reduce duplication of code and sharing pipelines among teams.
Posted June 14, 2021 by Adrian Wyssmann ‐ 11 min read
I want to use a regular expression to exclude a complete word. I need this for a particular situation which I explain further
Posted March 24, 2021 by Adrian Wyssmann ‐ 2 min read
Posted February 3, 2021 by Adrian Wyssmann ‐ 3 min read
It may happen that even so successful jenkins build remains "In Progress" in Bitbucket.
Posted January 13, 2021 by Adrian Wyssmann ‐ 3 min read
Did you ever pushed stuff to a git repo and then breaking your branch, just cause you did not checked beforehand, if all is fine. I'm sure you did. Wouldn't it be just cool if some checks ran automatically before committing or pushing?
Posted December 31, 2020 by Adrian Wyssmann ‐ 2 min read
Posted December 21, 2020 by Adrian Wyssmann ‐ 3 min read
Posted November 10, 2020 by Adrian Wyssmann ‐ 15 min read
Adding a slave to a Jenkins master always required to add the slave via the GUI and then gather the secret in order to be able to connect the slave. So I was wondering whether a slave could be created programmatically.
Posted March 15, 2019 by Adrian Wyssmann ‐ 2 min read
I got in touch with git when I was starting using Github. However as these projects were merely single contributor projects, some basic commands did it for my work there. There was no branching, no rebasing or whatsoever. Now after working on a daily basis with git and using it in big(ish) teams, I thought to write down a little guide for newbies on how to work with git.
Posted March 4, 2019 by Adrian Wyssmann ‐ 12 min read
Wow it has been already one year since I published my last blog entry. How time passes... Not that I have nothing to write, in contrary there are a lot of new exciting things I have done and learned in the past 1 and a half year since I've started my new job. Hopefully I find time again to write more again cause I really want to share whatever I can.
Posted March 1, 2019 by Adrian Wyssmann ‐ 2 min read
Posted November 30, 2017 by Adrian Wyssmann ‐ 11 min read
Posted November 2, 2017 by Adrian Wyssmann ‐ 3 min read
I recently run into the problem that my Harddisk (250GB) run full. Especially when installing Visual Studio, different SDKs (.Net, Android, ...), Microsoft Office, etc. your disk space may become rare. The problem is not only because of the size of these software but also cause Windows is keeping a lot of (unnecessary) files in various locations.
Posted October 19, 2017 by Adrian Wyssmann ‐ 5 min read
I wrote quick "Hands-on" for beginners to cover docker basics with simple containers so I won't go into details of complex application, service definitions or swarms. What I want to do is run a webserver inside a container with persistent data
Posted April 27, 2017 by Adrian Wyssmann ‐ 3 min read
Unattended installation is the possibility to install an operating system without human interaction. Principally it is the same for Windows and Linux: An "answer file" which describes the configuration is provided as an input for the installer. These "answer files" provide any kind of setup options including how to partition disks and what packages/features to install.
Posted April 12, 2017 by Adrian Wyssmann ‐ 4 min read
Powershell remoting enables to work on a remote computer as you may be used on Linux using ssh. In difference to Linux, where this is usually straight-forward, I find it a bit more complicated on Windows - however achievable. There are two was a remote PS connection can be established - via HTTP or HTTPS.
Posted March 11, 2017 by Adrian Wyssmann ‐ 6 min read
Posted January 27, 2017 by Adrian Wyssmann ‐ 1 min read
My work computer runs on Windows, so whenever I quickly need a VM, I use Virtualbox or VMWare Workstation. But my home computer runs on Linux and there I use KVM/Qemu instead - yes I also could use Virtualbox but I don't.
Posted December 23, 2016 by Adrian Wyssmann ‐ 1 min read
Software testing is not only running test cases but more of using a testers mindset and skills to find bugs and verify that the software is working correctly. However, usage of test cases (manual or automated) is essential to speed-up your testing and having reproducible tests for your regression testing. Obviously you want to be able to trust the tests - especially the outcome of these tests. However, regardless whether it is manual or automated testing, there are two terms you should understand and bear in mind. So what is it?
Posted December 19, 2016 by Adrian Wyssmann ‐ 8 min read
The public transport organization SBB recently opened platform for customer information data on public transport in Switzerland. Anyone can obtain obtain data on public transport free of charge and get access to specific public transport services for all licensed transport companies in Switzerland. The platform provides timetable, real-time and actual data.
Posted December 13, 2016 by Adrian Wyssmann ‐ 6 min read
Posted November 29, 2016 by Adrian Wyssmann ‐ 1 min read
When I used to work as test manager I encouraged my people to write issues/bugs that have certain quality. But actually this is not only true for testers but generally for everyone who reports bugs - especially if you are not in direct contact with the developers.
Posted October 17, 2016 by Adrian Wyssmann ‐ 7 min read