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Install rust

• https://rustup.rs

Install the rust language server and clippy tools:

$ rustup component add rustfmt rls
$ rustup component add clippy

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1. Create Pod config json file with privileged set as true in the security_context. Without a priveged pod, containerd does not allow a privileged container to be run in the sandbox.

{
    "metadata": {
        "name": "priv-sandbox",
        "namespace": "default",
        "uid": "0"
    },
    "log_directory": "/tmp",

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Despite changing time in the UI or through timedatectl, ubuntu seems to be reverting to the old timezone.

To change time and timezone in ubuntu:

sudo dpkg-reconfigure tzdata

Reference: https://askubuntu.com/questions/1092260/ubuntu-keeps-displaying-utc-time-despite-setting-timezone

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Prepare the host

Get the image clear-XXXXX-kvm.img

wget https://download.clearlinux.org/releases/30080/clear/clear-30080-kvm.img.xz
unxz clear-30080-kvm.img.xz

Add intel_iommu=on to the kernel boot parameters

mkdir mount_dir

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#!/bin/bash
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh

VMN=${VMN:=1}

NEMU=~/build-x86_64/x86_64-softmmu/qemu-system-x86_64

sudo $NEMU \
 -trace events=/tmp/events \

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$ sudo bpftrace -e 'tracepoint:napi:napi_poll /comm == "ping"/ { printf("%s\n", comm) }'
Attaching 1 probe...
ping
ping
ping

$ sudo bpftrace -e 'tracepoint:napi:napi_poll /comm == "ping"/ { printf("%d\n", args->work) }'

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This is only a trace on vxlan interface on the host. not from within container namespace

  ping-26819 [001]  3678.931358: fib_table_lookup:     table 254 oif 0 iif 1 proto 17 0.0.0.0/40784 -> 10.244.2.4/1025 tos 0 scope 0 flags 0 ==> dev flannel.1 gw 10.244.2.0 src 10.244.0.0 err 0
  ping-26819 [001]  3678.931387: fib_table_lookup:     table 254 oif 0 iif 1 proto 17 10.244.0.0/40784 -> 10.244.2.4/1025 tos 0 scope 0 flags 0 ==> dev flannel.1 gw 10.244.2.0 src 10.244.0.0 err 0
  ping-26819 [001]  3678.931468: fib_table_lookup:     table 254 oif 0 iif 1 proto 1 0.0.0.0/0 -> 10.244.2.4/0 tos 0 scope 0 flags 0 ==> dev flannel.1 gw 10.244.2.0 src 10.244.0.0 err 0
  ping-26819 [001]  3678.931485: fib_table_lookup:     table 255 oif 0 iif 0 proto 0 0.0.0.0/0 -> 10.244.2.4/0 tos 0 scope 0 flags 0 ==> dev flannel.1 gw 10.244.2.0 src 10.244.0.0 err 0
  ping-26819 [001]  3678.931499: net_dev_queue:        dev=flannel.1 skbaddr=0xffff919236689800 len=98
  ping-26819 [001]  3678.931500: net_dev_start_xmit:   dev=flann

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Overview

The goal of this document to cover all aspects of Kubernetes management, including how resources are expressed, constrained and accounted for. This started a way to ensure that alternate container runtime implementation like Kata containers will behave from a resource accounting and consumption point of view in the same manner as runc.

Location of the latest version of this document: https://gist.github.com/mcastelino/b8ce9a70b00ee56036dadd70ded53e9f

If you do not understand cgroups please refer to a quick primer at the bottom of this document. This will help you understand how the resource enforcement actually works.

Kubernetes Resource Management

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Guide for Cross-compilation of rust binaries (for eg. s390x)

The following steps describe the setup required to cross-compile a rust binary on a amd64 platform. These steps setup the cross-compile toolchain on the host itself. After going through these steps manually, I came accross a tool cross that makes the process way easier. It uses docker for the build and does not require any changes to the host. Jump to the section directly if you dont want to make any changes to the host.

Install the cross-compiler for s390x

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Installing kcli on Ubuntu

kcli is a handy tool for creating disposable VMs. You can also creata Kubernetes and OpenShift clusters with it. Refer to https://kcli.readthedocs.io/en/latest/ for more details. This gist describes the steps needed to setup kcli on an Ubuntu machine.

Install libvirt

sudo apt-get install libvirt-daemon-system libvirt-daemon-driver-qemu qemu-kvm
sudo adduser $USER libvirt