Should ModelPack standardize a Modelfile format?

[ericcurtin]

Background

A contributor recently opened docker/model-runner#903 to add Modelfile support to Docker Model Runner. The implementation follows Ollama's Modelfile format, which is oriented around runtime configuration (inference parameters, prompt templates, system prompts, etc.).

At the same time, modctl ships its own Modelfile format (via modctl modelfile generate), which serves a different purpose: describing packaging metadata for OCI artifacts (architecture, format, precision, weights, configs, etc.).

This gives us two things both called "Modelfile":

	modctl Modelfile	Ollama Modelfile
Purpose	OCI packaging metadata	Runtime/inference configuration
Key fields	NAME, ARCH, FORMAT, MODEL, CONFIG	FROM, PARAMETER, TEMPLATE, SYSTEM

Questions for the community

Does ModelPack plan to formally specify a Modelfile format as part of this spec?

[bergwolf]

The modelpack spec is to describe a model packaged in OCI format. Modelfile in modctl's case is to describe how to build the artifacts, while Modelfile in Ollama's case is for runtime to consume it. Right now they are actually two different files serving different purpose. Are you concerning the filename conflict or do you see some issue with the two Modelfiles?

On specifying a Modelfile format as part of this spec, IMO we should be open to it. Right now, there are multiple packaging tools (modctl/AIKit/KitOps). If there are interests in defining a common Modelfile format, we should go for it.

[ericcurtin]

The modelpack spec is to describe a model packaged in OCI format. Modelfile in modctl's case is to describe how to build the artifacts, while Modelfile in Ollama's case is for runtime to consume it. Right now they are actually two different files serving different purpose. Are you concerning the filename conflict or do you see some issue with the two Modelfiles?

I'm not concerned about the conflict.

On specifying a Modelfile format as part of this spec, IMO we should be open to it. Right now, there are multiple packaging tools (modctl/AIKit/KitOps). If there are interests in defining a common Modelfile format, we should go for it.

This is what I'm interested in, a CNCF/ModelPack defined standard. Ollama do lots of non-standard things, non-standard OCI artifacts, non-standard OCI transport, non-standard gguf files. So I'm interested in a CNCF/ModelPack defined standard of Modelfile.

[gorkem]

@ericcurtin The naming collision is unfortunate but worth separating from the question of scope.
Kitfiles in KitOps are packaging manifests, not runtime configs. The same is true for modctl's Modelfile. Ollama's Modelfile is a different artifact entirely: it describes how to run a model, not how to package one.

ModelPack is the packaging spec. It is not going to define a runtime config format and it should not be called Modelfile if it ever did.

What ModelPack can do, and arguably should, is extend the artifact's own metadata to carry runtime hints (chat template, recommended context length, stop tokens, etc.) as part of the config descriptor or annotations. Runtimes that consume ModelPack artifacts can then configure themselves directly from the artifact, without a separate Modelfile of either flavor. That is a different proposition from standardizing a Modelfile syntax.

Is the runtime-properties direction what you are looking for, or were you asking about a packaging Modelfile?