Let’s talk the OSI Model, or the Open Systems Interconnect Model. Level 4 is the transport layer. — Let’s talk the OSI Model, or the Open Systems Interconnect Model. Cloudflare describes the OSI Model pretty well: “The open systems interconnection (OSI) model is a conceptual model created by the International Organization for Standardization which enables diverse communication systems to communicate using standard protocols. In plain English, the OSI…

How do you check for the existence of a key in a Java HashMap? — In Java, the HashMap class that is part of the java.util package is incredibly useful. It’s Java’s map interface that allows you to store data in key value pairs that can then be accessed by an index. Among other advantages, you get to access data very quickly due to the…

If you’ve seen Bash scripts before, you might have come across set -u. So what does that mean? — If you’ve seen Bash scripts before, you might have come across set -u. It could look a little something like this: #!/bin/bash set -u city="Augusta" state="Georgia" echo "I live in $city, $state." What does that even mean? Well, first of all, let’s go over set. set is a command that…

What is the CKA exam given by the Cloud Native Computing Foundation? — The Certified Kubernetes Administrator (CKA) program was created in collaboration by the CNCF, or the Cloud Native Computing Foundation, and the Linux Foundation in an effort to help develop the Kubernetes ecosystem. CNCF further describes the lay of the land on their site: As one of the highest velocity open…

Manage your software in containers in Amazon Web Services ECR. — If you’re here, you want to know what AWS ECR or you just plain want to review what you already know. Either way, or whatever the reason you’re here, let’s get to the bottom of it. First of all, what even is AWS? AWS is Amazon Web Services, which is…

Let’s talk the OSI Model, or the Open Systems Interconnect Mode and what Level 7 means in network terms. — Let’s talk the OSI Model, or the Open Systems Interconnect Model. Cloudflare describes the OSI Model pretty well: “The open systems interconnection (OSI) model is a conceptual model created by the International Organization for Standardization which enables diverse communication systems to communicate using standard protocols. In plain English, the OSI…

Where is the config file for InfluxDB, a database technology, in the filesystem? — If you have InfluxDB running and you’re curious where the location of the configuration file, or influxdb.conf, is, then this is the article for you. First of all, it’s worth briefly mentioning what goes into this configuration file. You’ll find a internal defaults for InfluxDB initially set here, but you…

What is an A record when it comes to DNS and networking? — An A record is a means of pointing a host name to a site. An A record is a standard DNS (Domain Name Service) record, and the “A” stands for “Address”. The A record, in short, indicates the IP address of a domain. When you get the DNS records of…

Update the state of your remote objects with terraform refresh. — Okay, first of all, I’m going to let you know what the terraform refresh command does, but I want to note that this command is actually deprecated as of Terraform v0.15.4! Use it at your own risk for versions v0.15.4 and higher. For versions prior to that, then this article…