Feature image source This post continues from Operator SDK Part1 and looks at building the operators container image and running the operator. Building the Operator Container An operator container image contains the operator runtime for the type of operator and your business logic. The command make docker-build IMG=$IMG_NAME:TAG creates the operator container image using a Dockerfile in the projects root directory. The initialization process generates the Dockerfile based on the type of operator.

Feature image source The Operator-SDK is a command-line tool used by operator developers to build, test and package their operators. The SDK assists developers transform application business logic into a package which extends the Kubernetes API. Initializing a new project You need to provide the SDK with some necessary information to initialize the scaffolding for a new project. The initialization command is; operator-SDK init --domain $DOMAIN --plugin $PLUGIN. Parameters --domain sets the domain for API resources that this operator will create on the cluster.

Development and management of Kubernetes native applications is a difficult task with a steep learning curve. The operator framework aims to reduce the complexity by pooling shared expertise into a single project and standardize application packaging. Consumers benefit from operators’ automated operations, making it easier to keep their applications up to date and secure. The 3 Pillars Three pillars underpin the operator framework. The section below provides an overview of each pillar, and follow-up posts will cover each one in more detail.

This article is the first in a new series where I’ll attempt to explain Kubernetes Operators and how to build them in a concise and easy to digest manner. What is an operator? An operator is one or more custom resources and a control loop process which runs inside a pod on a Kubernetes cluster. What does an operator do? An operator manages a Kubernetes native application’s lifecycle by extending the Kubernetes API using custom resources (CR’s) specific to the application.