Ashley Aitken AshleyAitken

Functional Scala CRUD

We'll be adding a feature to Bootzooka, a skeleton Scala microservice/web application project.

This will involve using doobie, monix, tapir, http4s, circe and compile-time dependency injection.

If you'd like to follow along:

make sure you have Java & sbt installed. You can use sdkman for Java and popular package manages for sbt (e.g. brew)
git clone https://github.com/softwaremill/bootzooka.git

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

Applied Functional Programming with Scala - Notes

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

`docker-machine` import/export

Script to import and export docker-machine configurations to sync between hosts/collaborators

Export (on host A)

$ docker-machine ls
NAME       ACTIVE   DRIVER         STATE     URL                            SWARM   DOCKER    ERRORS
dev        -        digitalocean   Running   tcp://example.com:2376                 v1.10.1

	// Author: Sokdara Cheng
	// Contact me for web or mobile app development using React or React Native
	// https://chengsokdara.github.io
	import React, { createContext, useContext, useReducer } from "react";
	import initialState from "./initialState"; // object of initial states
	import reducer from "./reducer"; // https://reactjs.org/docs/hooks-reference.html#usereducer
	const Store = createContext({
	dispatch: () => null,
	state: initialState,
	});

	object Main extends App {
	import math._

	// The Expression Problem and my sources:
	// http://stackoverflow.com/questions/3596366/what-is-the-expression-problem
	// http://blog.ontoillogical.com/blog/2014/10/18/solving-the-expression-problem-in-clojure/
	// http://eli.thegreenplace.net/2016/the-expression-problem-and-its-solutions/
	// http://www.ibm.com/developerworks/library/j-clojure-protocols/

	package com.typesafe.config.impl

	import com.typesafe.config.ConfigFactory.parseMap
	import com.typesafe.config.{Config, ConfigFactory}

	import scala.collection.JavaConverters._
	import scala.io.Source
	import scala.util.Try

	// discussion: https://groups.google.com/forum/#!topic/play-framework-dev/t2g-TWbqtzY


	require('./module.js') // { a: 1 }
	import module from './module.js' // undefined
	import { a } from './module.js' // 1

	require('./module2.js') // { default: { a: 1 }, b: 2 }
	import module2 from './module2.js' // { a: 1}
	import { b } from './module2.js' // 2

	require('./module3.js') // { default: { a: 1 }, b: 2 }

	import os
	import shutil
	from sstash.sstash import SecureStash
	from getpass import getpass

	stash_path = "/my/path/to/stash/file"

	def store_machine(machine_name):
	"""
	Export a docker-machine from to the machines dir.