OCI (Open Containers Initiative)
The Open Containers Initiative (OCI) is a Linux Foundation project from 2015 that standardizes container technology. Before OCI, Docker was the only container format and platform-agnostic standardization around container tooling was lacking.
It provides a specification for container image formats (the OCI spec), to ensure interoperability across different container platforms.
OCI Image
Four components:
- Layer: What's inside an image, e.g. source code, container filesystem, etc.
config.json: How to run the containermanifest.json: Locate layers and configindex.json: index for a set of images spanning architectures and OS's
Containerfile:
FROM scratch # image based on empty base image COPY ./hello ./ # copy hello binary to the image ENTRYPOINT ["./hello"] # set as entrypoint for container