Akihiro Suda AkihiroSuda

Getting started with Linux kernel development

Prerequisites

The Linux kernel is written in C, so you should have at least a basic understanding of C before diving into kernel work. You don't need expert level C knowledge, since you can always pick some things up underway, but it certainly helps to know the language and to have written some userspace C programs already.

It will also help to be a Linux user. If you have never used Linux before, it's probably a good idea to download a distro and get comfortable with it before you start doing kernel work.

Lastly, knowing git is not actually required, but can really help you (since you can dig through changelogs and search for information you'll need). At a minimum you should probably be able to clone the git repository to a local directory.

Enable cgroups v2

# grubby --update-kernel=ALL --args="systemd.unified_cgroup_hierarchy=1"
# cat /etc/systemd/system/enable-cgroups.service 
[Service]
ExecStart=/bin/sh -c 'echo "+io +cpu +memory +pids +cpuset" > /sys/fs/cgroup/cgroup.subtree_control; mkdir /sys/fs/cgroup/user.slice; echo "+io +cpu +memory +pids +cpuset" > /sys/fs/cgroup/user.slice/cgroup.subtree_control'
Type=oneshot

[Install]
WantedBy=multi-user.target

Docker Hub 镜像加速器

国内从 Docker Hub 拉取镜像有时会遇到困难，此时可以配置镜像加速器。

Dockerized 实践 https://github.com/y0ngb1n/dockerized

1️⃣ Docker daemon 配置代理（推荐）

参考 Docker daemon 配置代理

Migrating from Knative Build

This doc describes a process for users who are familiar with Knative Build and BuildTemplate resources to migrate to Tekton TaskRuns and Tasks, respectively.

Tekton's resources are heavily influenced by Knative's Build-related resources, with some additional features that enable them to be chained together inside a Pipeline, and provide additional flexibility and reusability.

| Knative | Tekton |

Running Minikube via LXD

I make some assumptions, and make no claims in how well supported this is or ever will be. I wanted to avoid using VMs because i've been working in containers for the last half decade. It made sense to just skip the middle man and use a machine type container system to run my minikube workloads.

Why not juju?

Simply put, Juju does a fantastic job; but to stay objective I wanted to achieve minikube in LXD as a functional alternative to juju deploy kubernetes-core, or using KVM/VirtualBox in this solution.

#Use pprof debug docker daemon

Use pprof debug docker daemon
pprof debug entrypoint
Start docker daemon in debug mode
Run socat to make docker sock available via tcp port
Access debug url entrypoint

	445 DockerDaemonSuite.TestDaemonNoSpaceLeftOnDeviceError
	10008 2018-07-14 12:46:36 -0700 PDT centos-7-noselinux-devicemapper https://jenkins.dockerproject.org/job/Docker%20Master/label=centos-7-noselinux-devicemapper/10008/
	9945 2018-06-12 13:32:03 -0700 PDT ubuntu-1604-zfs-stable https://jenkins.dockerproject.org/job/Docker%20Master/label=ubuntu-1604-zfs-stable/9945/
	9759 2018-03-26 03:29:04 -0700 PDT rhel-74-selinux-overlay2-stable https://jenkins.dockerproject.org/job/Docker%20Master/label=rhel-74-selinux-overlay2-stable/9759/
	9758 2018-03-26 03:14:10 -0700 PDT rhel-74-selinux-overlay2-stable https://jenkins.dockerproject.org/job/Docker%20Master/label=rhel-74-selinux-overlay2-stable/9758/
	9757 2018-03-26 02:35:09 -0700 PDT rhel-74-selinux-overlay2-stable https://jenkins.dockerproject.org/job/Docker%20Master/label=rhel-74-selinux-overlay2-stable/9757/
	9755 2018-03-22 09:28:43 -0700 PDT rhel-74-selinux-overlay2-stable https://jenkins.dockerproject.org/job/Docker%20Master/label=rhel-74-selinux-ove

	!~Filename~:! !Moon's --TECO-- Library!
	LUNAR

	!& Load Airless Environment:! !S This is my init file
	It's here so that comments will get compressed.
	Argument is a string which is the user name!

	!* process job command line !
	hk fj 0,0a-3"E -d' !* remove ^C at end if any!
	0,-1a-15."E -2d' !* remove crlf at end if any.!

	package main

	import (
	"fmt"
	"io"
	"os"

	"github.com/fsouza/go-dockerclient"
	)

	#!/bin/bash

	# Retry a command until it succeeds or we've hit 10 attempts without it
	# returning 0.
	function retry_command
	{
	local tries=0
	local rc=1
	local max_tries=10
	local cmd="${@}"