The Hotel Hero

Notes by a Sysadmin

Cluster | Philosophy | Stack



Cloud & Cluster admin

Vanilla k8s on pi4 HA

February 28, 2023 |

The following is a HA setup of stacked etcd/cp on vanilla k8s, on rpi4 with 3 cp and 3 workers.

Storage is NFS nvme m2 hosted by one of the workers thru USB3.

OS: Ubuntu 22.04 lts server (arm).

Deploy tool: Kubeadm

Prepare the PI

Use the Image burner "Raspberry Pi Image burner",... Read more

Upgrading/Downgrading K3S

January 15, 2023 |

Currently I had a problem with Longhorn not compatible with k3s version v1.25.4+k3s1. So, after a lot of debugging I came to the conclusion that I had to do a downgrade of the cluster. I guess almost the same procedure would apply for an upgrade.


As you probably have some more fine grained... Read more

K3s Helm Traefik + LetsEncrypt

March 31, 2022 |

By default Traefik is deployed in K3s. So, in production we would like automating valid wildcard certificate creation. In this case there are two main approaches to generate and store certificates; cert-manager and traefik acme. On it's own Traefik acme can be used to create and store the certificate, but to get HA this way is... Read more

Rancher server HA on k3s

March 29, 2022 |

The following will assume that a K3s cluster is already up and running. We want to make it a starting point of our cluster management with the Rancher server distribution.

Note: If the installation fail or you somehow decide to make a reinstall of rancher. You will need to make a complete cleanup of... Read more

K3s cluster setup

March 25, 2022 |

K3s is Ranchers (SUSE) small kubernetes solution. In the following I'll try to create a small HA kubernetes cluster, made up of cheap VPS.

  • 3 node Masters
  • Any number of Workers
  • Etcd internal db
  • Loadbalancing

BTW: K3s can actually be run... Read more

MetalLB Load Balancer for K8s

January 24, 2022 |

Basically you would usually don't have to concern your self to much about this subject, when using the established cloud providers, as they usually have their own Load Blancer on the 2/3 OSI level. And networking in a K8s cluster is allready difficult for most people to get compfortably with. But, not to get confused with the... Read more

Wazuh single node on Swarm

August 6, 2021 |

As private user and a Open Source advocate. There is only a couple of SIEM systems to choose from, one of them is an offspring of the probably most known of them all OSSEC, this system is called Wazuh. One of the great things about Wazuh is the abillity to deploy a scalable container setup. In the following i will try to set... Read more

Ansible Vault

July 22, 2021 |

Often times it comes in handy to encrypt data, that are used for automation. Sensitive data like passwords and other credidentials for infrastructure should be handled with a certain amount of precaution.

Ansible Vault

Ansible vault is an encrypted storage to Ansible, even though it is also possible to... Read more

Traefik oauth

April 19, 2021 |

Make a traefik.yml in you project directory:

  # http redirect to https
    address: ":80"
          to: websecure
          scheme: https
  # https
    address: ":443"
       ...         Read more

Traefik ssl/tls consul

April 19, 2021 |

Start by setting up an overlay network:

docker network create --driver=overlay traefik-public

 Then we will export some variables befor deploying out docker-compose.yml:

export...         Read more

Nginx reverse proxy

April 16, 2021 |

Using jwilders configuration. Go to you project directory and create one directory (atleast), "conf.d" and maybe "html". Create a docker-compose.yml in the directory to (remember to change to the right path). Of cause you also need to figure out if you are running nginx on one or several nodes, in regard to storage and... Read more

Docker Hub - Create image

April 11, 2021 |

Create an image on Docker Hub, there are other ways of creating images. But, the following is based on a "Dockerfile".

"cd" into the directory of your Dockerfile, which is the formula for your image, and execute the following line:

docker build -t...         Read more

Portainer on Swarm

April 10, 2021 |

Portainer is a GUI admin tool for Docker (and K8s). And it is almost a "must have", not that you can't do without. But, this tool is really help full in getting and understanding of your whole cluster, it is stable and great for debugging.

The following "Stack" deployment will setup two services that run... Read more

Install Docker Swarm

April 10, 2021 |

Now, I came to Swarm after have been in the K8s universe for a year or so. And I just fell in love with Docker Swarm from first try. So, I would encurage anyone working with Pi's to choose Docker Swarm over any K8s solution out there, any day under any circumstances!

The first think and most complicated is to install... Read more

Mosquitto brocker - Docker Swarm Service

April 7, 2021 |

Setting a MQTT broker up on Swarm.

I have setup a nfs share that resides on each node and mounting is done on this share. In preparation I have have made the directories in the nfs-share that the bind is going to use.

The "stack" deployment file would look like this (usually you would probably... Read more

Docker Swarm Commands

April 5, 2021 |

Follow instructions on Docker for setting up Swarm and Portainer (easy)...

In Docker Swarm containers run in "services". Create a service:

docker service create --name redis --replicas=5 redis:3.0.6

Docker "ls" to list services:

Read more

Docker Swarm vs K8s - Pi cluster

April 5, 2021 |

In my experience Swarm is the ideal orchestration tool for ARM based clusters. Wait! Isn't Kubernetes the future for orchestration, and will Docker not drop support for Swarm in 2022 (you might say). And yes, very sadly! Most datacenters and companies working with container orchestration is moving towards the more complex... Read more

K8s Persistent Volume

March 8, 2021 |

Persisten Volume (Local)

There is a lot of different types of volume mounting, mainly because of the fact that Kubernetes (K8s) is often used for the purpose of high availabillity. So, the whole concept of storage on one node, is kind of opposed to that therminology. But, to try and make things simple here, we will use... Read more

Raspberry Pi Cluster setup considerations

February 19, 2021 |

There is a lot of tutorials out there about how to turn your Raspberry Pi's into a cluster. Before you do this yourself here are a couple of advices, depending of your goal with the project.

  • If you do not have any particular reason to learn Kubernetes, use Read more

Raspbian Buster 64 bit

January 25, 2021 |

By default Raspbian currently only take advantage of 32 bit in the core and user land event thou it has an 64 bit CPU in the latest PPi 4. Depending of the purpose of your Raspberry Pi, you may want to take advantage of the 64 bit ARM architecture ( you may be developing some applications or maybe want to use it for container... Read more


January 12, 2021 |

Generel configuration and setup of different kinds of UNIX-like Read more


I'm a Sysadmin, network manager and cyber security entusiast. The main purpose of this public "notebook" is for referencing repetitive tasks, but it might as well come in handy to others. Windows can not be supported! But all other OS compliant with the POSIX-standard can (with minor adjustments) apply the configs on the site. It is Mac OSX, RHEL and all the Fedora based distros and Debian based (several 100's of OS's), all the BSD distros, Solaris, AIX and HP-UX.