PhilipSchmid

Configure a Windows 10 KVM Guest to use an ultrawide display resolution (3440x1440)

1. virsh edit Windows10
2. Navigate to the <video> section and change it to the following one:

    <video>
      <model type='qxl' ram='131072' vram='131072' vgamem='32768' heads='1' primary='yes'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>

PhilipSchmid

Wireguard VPN Setup

This two scripts install & configure Wireguard on a CentOS8 "server" (peer) and on a Ubuntu 18.04 "client" peer. Of course, if you replace the # Installation script parts, these instructions can also be used on other distributions like Debian, CentOS 7, Fedora, etc..

Possible pitfall: When you change something in the /etc/wireguard/wg0.conf configuration file on the server, ensure to disable the wg-quick@wg0 service in advance:

sudo systemctl stop wg-quick@wg0
sudo systemctl disable wg-quick@wg0
sudo vim /etc/wireguard/wg0.conf    # edit what ever you like
sudo systemctl enable --now wg-quick@wg0

PhilipSchmid

Rancher K8s Cluster on VMware vSphere

Prerequisites

vCenter Configuration

• Configure the Network Protocol Profile on the vCenter according to: https://www.virtualthoughts.co.uk/2020/03/29/rancher-vsphere-network-protocol-profiles-and-static-ip-addresses-for-k8s-nodes/
• Ensure to create a service user with the regarding global and folder specific permissions: https://rancher.com/docs/rancher/v2.x/en/cluster-provisioning/rke-clusters/node-pools/vsphere/provisioning-vsphere-clusters/creating-credentials/
  • Beside the vCenter role permissions from the official Rancher documentation, the following ones need to be provided in order to configure the Nodes via vApp options:
    • Content Library: Read storage
    • Extension: Register extension
• vSphere Tagging: Assign or Unassign vSphere Tag on Object

PhilipSchmid

Clientless Linux remote access with Apache Guacamole

Quick and dirty guide how to get Apache Guacamole in combination with VNC up and running.

Apache Guacamole

Prerequisites

sudo add-apt-repository -y ppa:remmina-ppa-team/freerdp-daily
sudo apt update
env DEBIAN_FRONTEND=noninteractive sudo apt install -y freerdp2-dev freerdp2-x11

PhilipSchmid

Linux NIC to namespace (persisted via systemd service)

Save the file nic-isolation.service to /etc/systemd/system/nic-isolation.service.

Afterwards reload the systemd daemon and enable & start the "service":

sudo systemctl daemon-reload
sudo systemctl enable nic-isolation.service
sudo systemctl start nic-isolation.service

PhilipSchmid

Testing Multicast Traffic on Linux

Prerequisites

By default Linux ignores Broadcast and Multicast ICMP messages. That's why you need to enable it first:

sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=0

Join and Test Multicast Traffic

To join any mutlicast address (e.g. 224.10.10.10/24) just add it to your active interface (e.g. eth0) and append the keyword autojoin at the end:

PhilipSchmid

Rancher v2.X KeyCloak Authentication Backend Configuration

Ranchers official documentation about how to configure the Rancher <> KeyCloak setup is fine but definitely not sufficient to successfully configure it (https://rancher.com/docs/rancher/v2.x/en/admin-settings/authentication/keycloak/). That's the reason why here every single required step is documented down here.

KeyCloak Configuration

I simply use the default master realm for the Rancher client. Nevertheless, it would sometimes absolutely make sense to use a custom KeyCloak realm.

1. Login as admin on https://keycloak.example.com/. Important: It's crucial that in KeyCloak the same username exists as you use as admin user on Rancher. Since I just use the admin account in this guide, this prerequisite is already achieved.
2. Create a new client under https://keycloak.example.com/auth/admin/master/console/#/realms/master/clients
   • Client ID: https://rancher.example.com/v1-saml/keycloak/saml/metadata

PhilipSchmid

Let's Encrypt Traefik Docker Compose Example

version: "3.7"

services:
  lb:
    image: index.docker.io/traefik:v1.7.14-alpine
    hostname: traefik-webserver.example.com
    restart: unless-stopped

PhilipSchmid

Add Firefox Security Device (via CLI)

Use the following commands to add a security device module to Firefox. Ensure Firefox is closed while running these commands! modutil comes with the installation of libnss3-tools.

securityModuleDeviceName="My Awesome Module"
securityModulePath="/usr/lib/libBlaBla.so"
# We use cert9.db and "sql:..." since cert8.db is in the legacy format
for devicedDB in $(find  ~/.mozilla* -name "cert9.db")
do
 certDir=$(dirname ${devicedDB});

PhilipSchmid

Add CA certificates to the Firefox Truststore (via CLI)

Use the following commands to add CA certificates to the Firefox truststore via command line. Ensure Firefox is closed while running these commands! certutil comes with the installation of libnss3-tools.

certificateFileRoot="root.crt"
certificateNameRoot="Root CA"
certificateFileInter="intermediate.crt"
certificateNameInter="Intermediate CA"
# We use cert9.db and "sql:..." since cert8.db is in the legacy format
for certDB in $(find ~/.mozilla* -name "cert9.db")