Category Software Engineering

Introduction Elm is a functional programming language meant for building reliable web applications. It compiles to JavaScript and is well-known for its helpful compiler that promises no runtime errors. JavaScript is the de-facto language for building web applications. Today, we are building most of our web application logic in the frontend with JavaScript, and using […]

This article is part of our Faster Rails series. Check out the previous article about proper database indexing. As the scope and size of a Rails project grows, actions that were blazingly fast can become slow, and even downright unacceptable. The cause behind this issue can be an exponential growth of your database tables that […]

Adding new code to Rails controllers can bring a couple of problems with it. Sometimes controller actions get really big, and they tend to do a lot of things. Another common problem is an increase in data over time, which can lead to slow page loading time. Adding new code to controller actions can also […]

Introduction This tutorial will show you how to create an automation tool for deploying your software in a simple way, similar to deploying to Heroku. We’ll be using Docker to version control each deploy, which makes upgrades and rollbacks fairly easy. Also, we’ll use Semaphore to continuously deploy our application. Our containers can be hosted […]

Introduction Docker changed how development, testing and running software are done, and that’s why software engineers and companies should develop new habits and follow best practices. On the other hand, orchestration technologies like Docker Swarm, K8S or Mesos are also changing depending on the industry demands. Security management, including secret management in Docker Swarm, is […]

Introduction This tutorial is the second one in our series of articles on container orchestration with Docker Swarm. In the first tutorial, we covered how to bootstrap a Docker Swarm Mode cluster, and in this second tutorial, we’ll cover how Swarm schedules workloads across the cluster’s nodes. Scheduling is a key component of container orchestration, […]

Vagrant is a development environment automation tool. It accomplishes this by leveraging virtual machines with VirtualBox, VMWare, or cloud providers like AWS. It’s primarily designed to standardize environments across platforms. However, it’s not limited to that. Vagrant can be especially useful for cross-platform automated tests. By the end of this tutorial, you’ll be ready to […]

500px has been our customer since 2014, and they have been growing and evolving along with Semaphore. Moving fast is crucial to the 500px team. The less time they spend on testing, the more value they can create for their users. They put new code into production several times per day, and automated testing allows […]

In this tutorial, we will take a look at how Kafka can help us with handling distributed messaging, by using the Event Sourcing pattern that is inherently atomic. Then, by using a pattern called Command-Query Responsibility Segregation (CQRS), we can have a materialized view acting as the gate for data retrieval. Finally, we’ll learn how […]

If your Rails app is getting slower, here's how to properly index your database to make your Active Record queries faster.

One of the most important things we teach the junior programmers who join the Semaphore team is the mindset of shipping in small iterations. This is a simple concept, however there’s an inevitable misunderstanding that stems from the subjective ideas of “small”. Thus, in practice we need to teach by example what we really mean […]

Introduction When writing unit tests, you might come across a situation where you need to generate test data or use some dummy data in your tests. If you already have some data somewhere in a database, one solution you could employ is to generate a dump of that data and use that in your tests […]

Ansible is a general purpose automation tool that may be used for configuration management or workflow automation. Configuration management is an “infrastructure as code” practice that codifies things, e.g. what packages and versions should be installed on a system, or what daemons should be running. Workflow automation may be anything from provisioning cloud infrastructure to […]

Different teams have different approaches to dealing with flaky tests. Some even go as far as using the “Let’s run each test 10 times and if it passes at least once, it passed” approach.

Introduction Containers have recently become a very popular delivery mechanism for software applications. This is in part due to the popularity of the microservices software architecture pattern, which encourages delivering applications as a set of discrete, independent, loosely-coupled services. A microservice is an ideal payload for the container abstraction. Perhaps, the biggest influence, however, has […]