October 1st, 2020
Interesting AWS Jenkins Jobs
I recently built a new Jenkins server hosted using Kubernetes on EKS. My main use of the Jenkins server is to automate application and infrastructure tests, deployments, and miscellaneous tasks. I get email notifications if these jobs fail, so I know when there is an issue with my software.
Many of my Jenkins jobs work with the AWS CLI and Terraform to interact with and manipulate my cloud infrastructure. I believe these jobs may be useful as templates for others wishing to achieve similar results.
September 29th, 2020
Jenkins Server Modern Infrastructure with Kubernetes on EKS
In a prior article, I discussed a Jenkins server I created on AWS EC2 and EFS. In this article I’ll discuss the second generation of that infrastructure, which uses Docker containers orchestrated by Kubernetes on an EKS cluster.
September 28th, 2020
Building an AWS EKS cluster with Terraform
Recently I made the decision to move my applications to Kubernetes, specifically hosted in an EKS cluster on AWS. Before making this decision, my applications (saintsxctf.com and jarombek.com) were hosted using different methods. saintsxctf.com was hosted on autoscaled AWS EC2 instances and jarombek.com was hosted on AWS ECS. I also had prototypes using different hosting methods and a Jenkins server which was hosted on EC2 instances. Moving all these applications to Kubernetes unifies the deployment process and allows me to take advantage of containerization and container orchestration.
In this article, I'll discuss the process for setting up my EKS cluster with Terraform. I'll also detail my experience deploying ALB Ingress Controller and External DNS pods on the cluster.
September 27th, 2020
Jenkins Server Legacy Infrastructure on EC2 and EFS
Back in 2018, I created a Jenkins server which automated tasks for my applications. Jenkins is a continuous integration and continuous delivery (CI/CD) tool which I've written about in the past. When I first created the Jenkins server, I had a few jobs which ran unit tests, but I never took full advantage of them. Over the past two years, I've gained a greater appreciation for CI/CD tools and their ability to save time deploying code and building confidence in codebases by automating tests. Nowadays all my applications have automated test and deployment jobs on Jenkins.
Since 2018 the Jenkins ecosystem has evolved along with my understanding of cloud concepts. My original Jenkins server was hosted on an AWS EC2 instance which utilized AWS EFS for persistent storage. In the spring of 2020, I decided to rewrite the Jenkins server infrastructure. With my added knowledge of containerization with Docker and container orchestration with Kubernetes, I hosted the Jenkins server on AWS EKS as part of a Kubernetes deployment. In this article, I discuss the original EC2 Jenkins server and its creation process with Terraform. In an upcoming article, I'll discuss the Kubernetes Jenkins server infrastructure.
April 19th, 2020
Interesting Aspects of Pandas
In my previous article I walked through interesting aspects of numpy. I first learned numpy back in college during a course on Artificial Intelligence. With my daytime work becoming more Python based these past few months, I took numpy back up.
Before this winter, I never used pandas. Pandas is a data analysis library similar to numpy. In fact, pandas uses numpy arrays in many of its exposed methods. While numpy exposes an array data structure, pandas has two main data structures:
DataFrame. In general, pandas is commonly used for manipulating and analysing time series or table data (think SQL table or excel spreadsheet)1.
March 31st, 2020
Interesting Aspects of Numpy
In my new role at work, a good chunk of my programming is Python based and revolves around data analysis. I already knew Python, however I wanted a review libraries such as numpy and learn libraries such as pandas and matplotlib. This article discusses numpy, short for "Numerical Python". The goal of this article isn't to teach numpy to beginners, instead focusing on library aspects I found most interesting.
February 15th, 2020
Hosting a Static React Application on Amazon S3
Amazon S3 (Simple Storage Service) is an AWS service for storing objects. Since objects are files, S3 can be viewed as a filesystem accessible over HTTP. I often use S3 for storing images, fonts, and other assets for my applications. Some examples include my jarombek.com assets and my global shared assets.
Since Amazon S3 stores files and acts as a filesystem, it can also be used to host static websites.
February 5th, 2020
Unit, Integration, and Snapshot Testing in React with Jest and Enzyme
In an article last fall I spoke about my change in mindset towards unit testing. In my early programming days I thought unit tests slowed down development to a fault. Nowadays they are mandatory in all my applications. Unit tests are assertions that a unit of code is working as expected in isolation of other components in the codebase. They promote code review, help catch recurring bugs, and ease the burden of upgrading and switching technologies.
For React applications, the de facto testing framework is Jest. Jest was written by Facebook with React unit testing in mind, making it a natural fit. Alongside Jest, Enzyme is used to test React components. Enzyme was created by AirBnB to render components for testing. It provides an API to traverse the rendered DOM nodes in a component and hook into stateful component instances.
January 31st, 2020
Exploring New Features in React 16.3
When I was interviewing for jobs in the fall, one interviewer asked me if I had React 16 experience. I said "yes", figuring I must have worked on React 16 features during my year and a half experience. I've worked with React since I created a React and Webpack seed application in March 2018. Since then I wrote jarombek.com (the website you are currently viewing) in React along with contributing to a client-facing React application for seven months at my job.
As the interview questions rolled on, it became obvious that I wasn't utilizing the latest React features. Luckily I aced the coding assignment and other technology questions, so the interview ended up going well.
December 28th, 2019
Basic Elasticsearch Queries
Elasticsearch is a search and analytics engine. It's also a NoSQL database that holds JSON documents. These documents are stored in an inverted index and are queried with JSON syntax. In my previous article I explored analyzers and the process of storing documents in an inverted index. This article focuses on querying documents with JSON.
November 10th, 2019
The Basics of Programming Language Garbage Collection
While reading a book on C#, I came across a section about garbage collection. I always knew that programming languages such as Java performed garbage collection, but I never researched how garbage collectors (GCs) worked. The book mentioned that C# uses a tracing GC with generations and marking. These were foreign concepts to me, so I decided to conduct additional research on the topic. This article gives a high-level overview of garbage collectors and the APIs available to interact with them in Java and C#.
October 28th, 2019
Unit Testing AWS Infrastructure with Python
From October 2018 to May 2019, I moved the infrastructure for both my websites to AWS. The process for building and tearing down this infrastructure is automated with IaC, specifically Terraform. I've had a lot of fun working with Terraform and learning the different design patterns for infrastructure in the cloud.
After my infrastructure was built, I realized I needed a way to test that my IaC was behaving as expected. The obvious solution to this requirement was a unit test suite. I implemented this unit test suite in Python with the help of the AWS SDK. This article explains why I took the time to write unit tests and walks through of the basics of testing AWS infrastructure in Python.