In order to facilitate compatibility with ETSI, ONAP and other telco standards, the CSAR (NFV SOL 004ed351 or ed421) packaging format is used. The only modification is allowing the proposed Application Service Descriptor (ASD) to be a top-level descriptor for the package, instead of an NSD or VNFD as defined in SOL001.
Additionally, the following directories will exist inside the CSAR:
deployment_artifacts: where all deployment files go, like Helm charts.
images: holds container images referenced from the main application and dependencies, in OCI format.(ref: https://github.com/opencontainers/image-spec)
Note that the “images” directory may be empty, or only contain a part of the images required for the whole application. This might happen for example in application update packages, where the container images may have already been onboarded onto the associated registry. In case images are present, they must be referenced in the CSAR manifest.
This application packaging format is designed to support a single, container-based deployment “flavor” or “type”. If an application has multiple such deployment types, there should be multiple packages, with their own appropriate descriptors.
An orchestrator is expected to load any container images present in the package onto the correct registry for the target cluster(s) before attempting to deploy the application. Since the images are in OCI format, they should follow the OCI image layout specification, and MUST contain a “name” annotation in their index.json layout descriptor. This name should be used as the “tag” value when the orchestrator provisions the image in the corresponding registry.
Working/discussion material: