Dots and Brackets: Code Blog - Page 8 of 8 - Blog about DevOps, distributed applications and microservices

3 ways to dockerize existing Node.js app

Dockerize all the things Imagine you have Node.js app you would like to run from within Docker container. Maybe you want to check if it still works on ‘another’ machine, or it’s a test run before adopting containers as the way of software delivery. Reasons may vary.

In order to have something tangible, let’s pick hello.js app which prints out ubiquitous ‘Hello World’:

var http = require('http');
	
http.createServer(function (_, response) {
		response.writeHead(200, {"Content-Type": "text/plain"});
		response.end("Hello World\n");
	})
	.listen(8080);

var http = require('http');

http.createServer(function (_, response) {

response.writeHead(200, {"Content-Type": "text/plain"});

response.end("Hello World\n");

})

.listen(8080);

localhost-hello
How do we put it into container? Continue reading “3 ways to dockerize existing Node.js app”

Quick intro to Docker

What’s Docker.

docker On the surface Docker looks like another virtual machine (VM). Just pick Ubuntu image with hello-world app inside, type docker run ubuntu hello-world in your terminal of choice, and hello-world will start, thinking it owns a whole machine running Ubuntu.

But Docker is not a VM, manager of VMs, or hypervisor of any kind. Docker is a platform for creating, launching and managing containers. Those looks like VMs, quack like VMs, but are much closer to a fence with a barbwire on top of it. No app can enter, no app can leave. What is bad for humans works great for applications in production environment.

Because Docker doesn’t have to deal with guest operating system and hardware abstraction, it can work with the speed that VMs can only dream of, while doing quite similar job. Continue reading “Quick intro to Docker”

Playing with microservices

Recently I was asked to build a small internal app: dynamic dashboard for one of our projectors, which are hanging all over the office and display some company info onto the walls: customer statistics, server-to-server latency, what tasks are in development, etc. My particular goal was to add release and builds statistics: build duration, failed/unreliable tests and anything else that could motivate us to produce more stable builds.

We store all relevant data in Google BigQuery and the whole task is basically to extract build results from the storage and present it in clear and simple way. Quite trivial. Continue reading “Playing with microservices”