kwilczynski

ccflags-y := -DDEBUG -Wfatal-errors

ifneq ($(KERNELRELEASE),)
	obj-m += state-toggle.o
else
	BUILD_KERNEL ?= /lib/modules/$(shell uname -r)/build
default:
	$(MAKE) -C $(BUILD_KERNEL) M=$(CURDIR) modules
endif

aojea

Kubernetes DNS at scale

It seems that is a common practice in HPC and AI/ML environments that use MPI applications to populate a hosts files with all the nodes on the cluster and copy it over all the nodes, ref https://help.ubuntu.com/community/MpichCluster

It is my observation that in Kubernetes, Headless Services are used to implement this Service Discovery This is very handy because it allows to reference a pod by hostname without having to copy over a generace /etc/hosts.

There must also be an A record of the following form for each ready endpoint with hostname of and IPv4 address . If there are multiple IPv4 addresses for a given hostname, then there must be one such A record returned for each IP.

aojea

# See for more options https://kubernetes.io/docs/concepts/workloads/controllers/daemonset/
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: node-ethtool
  namespace: kube-system
  labels:
    k8s-app: node-ethtool-config
spec:
  selector:

kwilczynski

  Fixes:
  Closes:
  Suggested-by:
  Link:
  Reported-by:
  Tested-by:
  Co-developed-by: (co-author)
  Signed-off-by: (co-author)
  Signed-off-by: (author)
  Signed-off-by: (chain)

aojea

BPF Cheatsheet

Download binary

curl -s -L https://github.com/libbpf/bpftool/releases/download/v7.2.0/bpftool-v7.2.0-amd64.tar.gz | tar xvzf - -C /tmp chmod +x /tmp/bpftool

List network

saschagrunert

# -*- mode: ruby -*-
# vi: set ft=ruby :

# Vagrant box for testing
Vagrant.configure("2") do |config|
  config.vm.box = "fedora/35-cloud-base"
  memory = 6144
  cpus = 4

  config.vm.provider :virtualbox do |v|

rbitr

Random numbers in bash et al

There is a variable $RANDOM than you can read in bash or zsh to get a random number beteen 0 and 32767. Here in zsh on my (old) mac:

% echo $RANDOM
13757
% echo $RANDOM
16896

kwilczynski

$argon2id$v=19$m=64,t=512,p=2$G/DQSn2+4afFDXZRdR3Vlw$DBvv46nt3EEkY5ehfDVfQQ

kwilczynski

Keybase proof

I hereby claim:

• I am kwilczynski on github.
• I am kwilczynski (https://keybase.io/kwilczynski) on keybase.
• I have a public key whose fingerprint is 12D2 7D5D 8C8E 9BF1 AABC 7C7C 7C64 768D 3DE3 34E7

To claim this, I am signing this object:

kwilczynski

name: "Auto-merge Dependabot Pull Request for Dockerfile updates"

permissions:
  pull-requests: write
  contents: write

on:
  pull_request_target:
    branches:
      - main