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Setting Up Clojure on OS X

I spent a lot of time trying to find a pretty optimal (for me) setup for Clojure… at the same time I was trying to dive in and learn it. This is never optimal; you shouldn't be fighting the environment while trying to learn something.

I feel like I went through a lot of pain searching Google, StackOverflow, blogs, and other sites for random tidbits of information and instructions.

This is a comprehensive "what I learned and what I ended up doing" that will hopefully be of use to others and act as a journal for myself if I ever have to do it again. I want to be very step-by-step and explain what's happening (and why) at each step.

I appreciate the effort you've put into documenting this, but there are a number of inaccuracies here that need to be addressed. We get

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Referencing this discussion on how to deny loopback access, create the opposite which is to only allow access from localhost. The goal is to only allow access after the client has connected with SSH using the port tunneling option.

Add new filter rules to block VNC (port 5900) access when not connected via SSH with port forwarding. Plus add blocks to file sharing (SMB and AFP). Just in case I am running a web server block that too, or any other ports listed in this link.

# pfctl is the packet filter firewall for modern OS X. 
# For more info -> man pfctl
# flush to the default

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Setup testnet Ethereum network with Docker

Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of downtime, censorship, fraud or third party interference.

This is step-by-step guide, how to setup testnet Ethereum network.

We'll setup ethereum testnet node in the docker container and write ruby json-rpc client. The difference between ethereum(Frontier) and testnet ethereum(Ropsten) networks is that the testnet used for development. The genesis block on the testnet was set with a very low difficulty so anyone can do minning. The coins mained in the testnet have no values. You can request some coins on the facuet or trying to mine it.

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Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

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async/await is just the do-notation of the Promise monad

CertSimple just wrote a blog post arguing ES2017's async/await was the best thing to happen with JavaScript. I wholeheartedly agree.

In short, one of the (few?) good things about JavaScript used to be how well it handled asynchronous requests. This was mostly thanks to its Scheme-inherited implementation of functions and closures. That, though, was also one of its worst faults, because it led to the "callback hell", an seemingly unavoidable pattern that made highly asynchronous JS code almost unreadable. Many solutions attempted to solve that, but most failed. Promises almost did it, but failed too. Finally, async/await is here and, combined with Promises, it solves the problem for good. On this post, I'll explain why that is the case and trace a link between promises, async/await, the do-notation and monads.

First, let's illustrate the 3 styles by implementing

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Why or why not Dart?

This is my analysis of the Dart language. Overall, some parts I like, some parts I don't like and my overall view of it all.

My background

Depending on what my employers have required on the backend, I've used C#, node.js, PHP, Python & dashes of Ruby. I personally enjoy Javascript, and I'm especially a fan of node.js. I also really like CoffeeScript, and now that it has source maps, it could very well become something I use daily.

Below are my thoughts on Dart:

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unless ARGV.size > 0
  puts "  Missing executable file argument"
  puts "  Usage (in a Dockerfile)"
  puts "  RUN crystal run ./path/to/list-deps.cr -- ./bin/executable"
  exit 1
end

executable = File.expand_path(ARGV[0])

unless File.exists?(executable)

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App configuration in environment variables: for and against

For (some of these as per the 12 factor principles) 

1) they are are easy to change between deploys without changing any code

2) unlike config files, there is little chance of them being checked
into the code repo accidentally

3) unlike custom config files, or other config mechanisms such as Java

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package main

import (
	"crypto/tls"
	"crypto/x509"
	"flag"
	"io/ioutil"
	"log"
	"net/http"
)

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This demonstrates how to make client side certificates with go

First generate the certificates with

./makecert.sh [email protected]

Run the server in one terminal

go run server.go