Installing Elasticsearch/Kibana 5.5 within Kubernetes cluster on AWS
In my previous blog post I showed how to use the Kops tool to create a production ready Kubernetes cluster on Amazon Web Services (AWS). In this follow-up post I will show how to install Elasticsearch and its graphical counterpart Kibana in the cluster, in order to be able to collect and store logs from your cluster and search/read them. We will also install Fluentd as this component is responsible for transmitting the standard Kubernetes logs to Elasticsearch. This is generally known as the ELK stack, which stands for Elasticsearch, Logstash (precursor to Fluentd) and Kibana.
Creating a Highly Available Secured Kubernetes Cluster on AWS with Kops
Today I will be talking about Kops, which is an official tool for creating Kubernetes clusters on AWS, with support for GCE and VMware vSphere in alpha. It takes a whole lot of the pain out of setting up a Kubernetes cluster yourself, but still presents many challenges to overcome and a great degree of freedom in how you configure the cluster.
I have recently created a Kubernetes cluster on AWS for a client, where I used the Kops tool for the very first time and I will here present what I learnt about implementing best practices with this technology stack. Given the rapid development of Kubernetes itself, and how relatively young Kops is, it proved to be far from a walk in the park to create a production-grade cluster. Documentation is often relatively poor, or just plain missing. The intention of this blog post is to make it easier for others going down the same route.
Route Handling Framework for Choo
I’ve made a complementary route handling framework for Yoshua Wuyts' JavaScript SPA (Single Page Application) framework Choo: choo-routehandler. For those unfamiliar with Choo, it’s a view framework similar to React and Marko, although with a strong focus on simplicity and hackability and working directly with the DOM instead of a virtual DOM (unlike React).
Basically, the motivation for making the framework was that I found myself implementing the same pattern in my Choo apps: To load data before rendering a view corresponding to a route and to require authentication before accessing certain routes. I didn’t find any good way to handle this baked into Choo, even though it has a rather good routing system built into it. It was also tricky to use Choo’s standard effects/reducers system to implement handling of route change, since these are asynchronously triggered and I could end up handling the same route change several times as a result.
Avoiding Popup Blocking when Authenticating with Google
When I recently implemented Google authentication in a Web app, I discovered that I fell victim to the browser’s built-in popup blocking mechanism, which would hide Google’s requisite login dialog. While popup blocking can be pretty good to have in the face of more or less malicious websites and intrusive ads, it’s a real drag when trying to implement something so beneficial, not to say fundamental, as authentication.
At least in the end, I learned something from overcoming this challenge. What I came to realize is that browsers distinguish between (likely) wanted and unwanted popups, by determining whether popups were initiated by user clicks. What this comes down to technically, in programming terms, is that the stackframe opening the popup (via window.open) must be close on the stack to the one handling the click event.
Event Catalogue for Berlin Released
I’m finally ready to share what I’ve been working on for the last few months, an online catalogue of underground cultural events in the city of Berlin: Experimental Berlin. My best effort to date I think! For this project I’ve been using Yoshua Wuyts' excellent JavaScript framework Choo.
Maintainership of html-to-react
I’m happy to announce that I’ve taken over maintainership of the popular NPM package html-to-react, which currently has about 3600 downloads per month. This package has the ability to translate HTML markup into a React DOM structure.
An example should give you an idea of what html-to-react brings to the table:
var React = require('react');
var HtmlToReactParser = require('html-to-react').Parser;
var htmlInput = '<div><h1>Title</h1><p>A paragraph</p></div>';
var htmlToReactParser = new HtmlToReactParser();
// Turn HTML into a bona fide React component that we can integrate into our React tree
var reactComponent = htmlToReactParser.parse(htmlInput);Achieving Infinite Scrolling with React.js
As part of developing MuzHack I had to implement a method of loading search results on demand, i.e. not everything at once. I decided on the "infinite scrolling" method, which means that as seen on f.ex. Twitter, you load more content as the user scrolls down the page. This is an alternative to the more traditional pagination method, where content (e.g. search results) is partitioned into pages, and the user loads more content by explicitly navigating to another page.
Zero Downtime Docker Deployment with Amazon ECS
Earlier, I wrote about zero downtime docker deployment with Tutum. I have recently started experimenting with Amazon ECS (EC2 Container Service), which is Amazon’s offering for the orchestration of Docker containers (and thus a competitor to Tutum). I don’t have a lot of experience with ECS yet, but it looks pretty solid so far.
I found there was a real lack of documentation on how to deploy updated Docker images to Amazon, however, and was forced to do some research in order to figure out how it should be done. Through some diligent experimentation of my own with the AWS ECS CLI and not least some valuable help on the Amazon forums, I was able to come up with a script and requirements for the ECS configuration that together lead to streamlined deployment. As it turns out, you even get zero downtime deployment for free (provided that you use an elastic load balancer, mind)! It’s more magical than in the Tutum case, as ECS by default upgrades one node after the other in the background (hidden by the load balancer) so long as it is allowed to take down at least one node as required.
MuzHack featured in Electronic Beats
Electronic Beats Magazine did a quick writeup on my MuzHack project. Nice that people are paying attention!
Uploading Files to Amazon S3 Directly from the Web Browser
Amazon S3 is at the time of writing the premier file storage service, and as such an excellent choice for storing files from your Web application. What if I were to tell you these files never need to touch your application servers though?
The thing to be aware of is that the S3 API allows for POST-ing files directly from the user’s Web browser, so with some JavaScript magic you are able to securely upload files from your client side JavaScript code directly to your application’s S3 buckets. The buckets don’t even have to be publicly writeable.