E Camden Fisher fishnix

INTRO

Concurrency is a domain I have wanted to explore for a long time because the locks and the race conditions have always intimidated me. I recall somebody suggesting concurrency patterns in golang because they said "you share the data and not the variables".

Amused by that, I searched for "concurrency in golang" and bumped into this awesome slide by Rob Pike: https://talks.golang.org/2012/waza.slide#1 which does a great job of explaining channels, concurrency patterns and a mini-architecture of load-balancer (also explains the above one-liner).

Let's dig in:

Goroutines

This guide has moved to a GitHub repository to enable collaboration and community input via pull-requests.

https://github.com/alexellis/k8s-on-raspbian

Alex

2021 Update: Easiest option is Justin's repo and image

Just run this from your Mac terminal and it'll drop you in a container with full permissions on the Docker VM. This also works for Docker for Windows for getting in Moby Linux VM (doesn't work for Windows Containers).

docker run -it --rm --privileged --pid=host justincormack/nsenter1

more info: https://github.com/justincormack/nsenter1

I have been an aggressive Kubernetes evangelist over the last few years. It has been the hammer with which I have approached almost all my deployments, and the one tool I have mentioned (shoved down clients throats) in almost all my foremost communications with clients, and it was my go to choice when I was mocking my first startup (saharacluster.com).

A few weeks ago Docker 1.13 was released and I was tasked with replicating a client's Kubernetes deployment on Swarm, more specifically testing running compose on Swarm.

And it was a dream!

All our apps were already dockerised and all I had to do was make a few modificatons to an existing compose file that I had used for testing before prior said deployment on Kubernetes.

And, with the ease with which I was able to expose our endpoints, manage volumes, handle networking, deploy and tear down the setup. I in all honesty see no reason to not use Swarm. No mission-critical feature, or incredibly convenient really nice to have feature in Kubernetes that I'm go

Latency Comparison Numbers

Note: "Forked" from Latency Numbers Every Programmer Should Know

Event	Nanoseconds	Microseconds	Milliseconds	Comparison
L1 cache reference	0.5	-	-	-
Branch mispredict	5.0	-	-	-
L2 cache reference	7.0	-	-	14x L1 cache
Mutex lock/unlock	25.0	-	-	-

Setting up Pi Zero OTG - The quick way (No USB keyboard, mouse, HDMI monitor needed)

More details - http://blog.gbaman.info/?p=791

For this method, alongside your Pi Zero, MicroUSB cable and MicroSD card, only an additional computer is required, which can be running Windows (with Bonjour, iTunes or Quicktime installed), Mac OS or Linux (with Avahi Daemon installed, for example Ubuntu has it built in).
1. Flash Raspbian Jessie full or Raspbian Jessie Lite onto the SD card.
2. Once Raspbian is flashed, open up the boot partition (in Windows Explorer, Finder etc) and add to the bottom of the config.txt file dtoverlay=dwc2 on a new line, then save the file.
3. If using a recent release of Jessie (Dec 2016 onwards), then create a new file simply called ssh in the SD card as well. By default SSH i

	name old time/op new time/op delta
	BinaryTree17 5.44s ± 2% 3.27s ± 2% -39.90% (p=0.000 n=20+19)
	Fannkuch11 4.95s ± 2% 2.68s ± 2% -45.87% (p=0.000 n=20+20)
	FmtFprintfEmpty 142ns ± 2% 49ns ± 3% -65.39% (p=0.000 n=20+18)
	FmtFprintfFloat 765ns ± 2% 260ns ± 2% -66.02% (p=0.000 n=20+20)
	FmtFprintfInt 341ns ± 2% 95ns ± 2% -72.08% (p=0.000 n=19+20)
	FmtFprintfIntInt 554ns ± 2% 150ns ± 1% -72.95% (p=0.000 n=20+19)
	FmtFprintfPrefixedInt 497ns ± 3% 178ns ± 3% -64.12% (p=0.000 n=20+20)
	FmtFprintfString 466ns ± 2% 86ns ± 3% -81.54% (p=0.000 n=20+20)
	FmtManyArgs 2.23µs ± 2% 0.59µs ± 1% -73.46% (p=0.000 n=20+17)

	pipeline {
	agent {
	// "node" is a new agent type that works the same as "label" but allows
	// additional parameters, such as "customWorkspace" below.
	node {
	label "some-label"
	// This is equivalent to the "ws(...)" step - sets the workspace on the
	// agent to a hard-coded path. If it's not an absolute path, it'll be
	// relative to the agent's workspace root.
	customWorkspace "/use/this/path/instead"

	// A Declarative Pipeline is defined within a 'pipeline' block.
	pipeline {

	// agent defines where the pipeline will run.
	agent {
	// This also could have been 'agent any' - that has the same meaning.
	label ""
	// Other possible built-in agent types are 'agent none', for not running the
	// top-level on any agent (which results in you needing to specify agents on
	// each stage and do explicit checkouts of scm in those stages), 'docker',

	#!groovy

	// This is the full syntax for Jenkins Declarative Pipelines as of version 0.8.1.

	pipeline {
	// Possible agent configurations - you must have one and only one at the top level.
	agent any
	agent none
	agent {
	label "whatever"