Containerbilder

Containerbilder refers to container images, which are lightweight, standalone, executable packages that include everything needed to run a piece of software. These images contain the application code, runtime, system tools, libraries, and all other dependencies required for the software to function properly across different computing environments.

The concept emerged as a fundamental component of containerization technology, most notably associated with Docker platforms. Container images are built from layered file systems, where each layer represents a specific component or modification to the base image. This layered architecture enables efficient storage and distribution, as common layers can be shared between multiple images.

Container images are typically created using Dockerfiles or similar configuration files that define the build process step by step. The build process starts with a base image, often derived from minimal operating systems like Alpine Linux or specialized runtime environments, and sequentially applies instructions to install dependencies, copy application files, and configure the environment.

Once built, container images can be stored in registries, both public and private, making them easily distributable across development, testing, and production environments. Popular registries include Docker Hub, Google Container Registry, and Amazon Elastic Container Registry.

The primary advantage of container images lies in their portability and consistency. Applications packaged as container images will run identically regardless of the underlying infrastructure, eliminating the common "works on my machine" problem. This characteristic has made container images essential for modern software development practices, including microservices architectures, continuous integration and deployment pipelines, and cloud-native application development.

Container images are immutable by design, meaning once created, they cannot be changed. This immutability ensures reproducible deployments and simplifies version control, as each image version represents a specific, unchangeable state of the application and its dependencies.