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#cloud-config
hostname: rancher-os
ssh_authorized_keys:
  - ssh-rsa AAAABBBBBBCCCCCCC...
write_files:
  - path: /opt/rancher/bin/start.sh
    permissions: 0700
    content: |
      #!/bin/bash
      # Configure private network on eth1

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Quick Start for getting acquainted with Docker for Node.js developers

Install Dependencies

Install Docker Toolbox

For Mac and Windows users, just install Docker Toolbox. It provides what you need to get started, including:

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Bash / Clone all GitHub repositories of a user

See my GitHub API current rate limits:

curl -sI "https://api.github.com/users/cookbooks/repos" | grep "^X-RateLimit" Any left? curl -sI "https://api.github.com/users/cookbooks/repos" | sed -nr 's/^X-RateLimit-Remaining: (.*)$/\1/p'

Or even simpler:
curl -s "https://api.github.com/rate_limit"

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What

A lot of times you are developing a web application on your own laptop or home computer and would like to demo it to the public. Most of those times you are behind a router/firewall and you don't have a public IP address. Instead of configuring routers (often not possible), this solution gives you a public URL that's reverse tunnelled via ssh to your laptop.

Because of the relaxation of the sshd setup, it's best used on a dedicated virtual machine just for this (an Amazon micro instance for example).

Requirements

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Using Cloudfront CDN with a Rails app

Stop serving assets from your own nginx instance. Instead, let Cloudfront CDN do it for you.

Steps:

1. Read http://ryantownsend.co.uk/post/13126016608/cloudfront-cdn-on-rails
2. Set up your nginx virtual host according to the snippet I've included in nginx_vhost.conf
3. Set up your rails app to use an asset host as described in the article. I've included my config in production.rb

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consul-stack:
  series: trusty
  services:
    haproxy:
      charm: "local:trusty/haproxy"
    etcd:
      charm: "local:trusty/etcd"
      num_units: 3
      to: [0, docker, docker]
    registrator:

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# assumming path to nginx is /etc/nginx/
sudo su
cd /etx/nginx
mkdir certs_localhost
cd certs_localhost

# generate self signed certificate, the identifier for it should be localhost
openssl req -x509 -newkey rsa:2048 -keyout development.key -out development.crt -days 5000 -nodes
cd ..

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#
# Shared definition of ruby microservice
#
microservice:
  command: "runsvdir /etc/service"
  environment:
    PORT: 3000
    RAILS_ENV: development
    SERVICE_PLATFORM: "mia"
  ports:

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Using the nc command you can scan a port or a range of ports to verify whether a UDP port is open and able to receive traffic.

This first command will scan all of the UDP ports from 1 to 65535 and add the results to a text file:

$ nc -vnzu server.ip.address.here 1-65535 > udp-scan-results.txt

This merely tells you that the UDP ports are open and receive traffic.

Perhaps a more revealing test would be to actually transfer a file using UDP.

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# SSL self signed localhost for rails start to finish, no red warnings. 

# 1) Create your private key (any password will do, we remove it below)

$ openssl genrsa -des3 -out server.orig.key 2048


# 2) Remove the password

$ openssl rsa -in server.orig.key -out server.key