Containers

Imagine a green, sustainable city, meticulously designed for environmental harmony and efficiency. The city has many distinct localities such as neighborhoods, districts, and even villages with their own identity and cultures. This city boasts an intricate public transport system, with buses, trams, and subways efficiently transporting citizens to their destinations from its various localities. Multiple such cities are connected together in a thriving, fast-paced ecosystem. The cities are also similarly connected in an efficient and sustainable design....

Sidecar pattern is a single-node pattern made up of two containers. It involves co-locating another container in a node/pod along with the main application container. The application container contains the core logic for the application. The role of the sidecar is to augment and improve the application container, often without the application container’s knowledge. In its simplest form, a sidecar container can be used to add functionality to a container that might otherwise be difficult to add....

A single container provides application isolation and mobility. However, a container by itself doesn’t improve the quality of your service—for example, in terms of load balancing or failover. This is where multi-container solutions come into play. However managing a handful of containers is completely different from managing production-scale containers, which may number from hundreds to thousands. To support container management, we need an easy way of deploying and handling these containers at scale....

Controllers create and manage pods. Controllers respond to pod state and health. Kubernetes lets you assert that resources such as pods are in a certain desired state, with specific versions. Controllers track those resources and attempt to run your software as described. There are a variety of controllers in Kubernetes, primarily ReplicaSets and Deployments. ReplicaSet - A ReplicaSet is responsible for reconciling the desired state at all times. The ReplicaSet is used to define and manage a collection of identical pods that are running on different cluster nodes....

Pods are an important feature of Kubernetes. A Pod is the smallest unit of work that Kubernetes manages and is the fundamental unit that the rest of the system is built on. Each pod contains one or more containers. Instead of deploying containers individually, you always deploy and operate on a pod of containers. Pods are always scheduled together (always run on the same machine). A pod is as an atomic unit....

I have been working with multiple teams on containerizing their infrastructure using docker. A while back I needed to help a team understand Docker containers by getting them to dive in and get started rather than just talk and point to slide decks. We started by containerizing the simplest possible .net core console app. The first app we built was a simple console app that used a timer and printed the date and time every 2 seconds....