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The OCI Image Format project creates and maintains the software shipping container image format spec (OCI Image Format).

The specification can be found here.

This repository also providesGo types,intra-blob validation tooling, and JSON Schema.The Go types and validation should be compatible with the current Go release; earlier Go releases are not supported.

Additional documentation about how this group operates:

• Code of Conduct
• Roadmap
• Releases

The OCI Image Format partner project is theOCI Runtime Spec project.The Runtime Specification outlines how to run a "filesystem bundle" that is unpacked on disk.At a high-level an OCI implementation would download an OCI Image then unpack that image into an OCI Runtime filesystem bundle.At this point the OCI Runtime Bundle would be run by an OCI Runtime.

This entire workflow supports the UX that users have come to expect from container engines like Docker and rkt: primarily, the ability to run an image with no additional arguments:

• docker run example.com/org/app:v1.0.0
• rkt run example.com/org/app,version=v1.0.0

To support this UX the OCI Image Format contains sufficient information to launch the application on the target platform (e.g. command, arguments, environment variables, etc).

TheOCI Distribution Spec Project defines an API protocol to facilitate and standardize the distribution of content.This API includes support for pushing and pulling OCI images to an OCI conformant registry.

Q: What happens to AppC or Docker Image Formats?

A: Existing formats can continue to be a proving ground for technologies, as needed.The OCI Image Format project strives to provide a dependable open specification that can be shared between different tools and be evolved for years or decades of compatibility; as the deb and rpm format have.

Find moreFAQ on the OCI site.

TheGitHub milestones lay out the path to the future improvements.

Development happens on GitHub for the spec.Issues are used for bugs and actionable items and longer discussions can happen on themailing list.

The specification and code is licensed under the Apache 2.0 license found in theLICENSE file of this repository.

The project welcomes submissions, but please let everyone know what you are working on.

Before undertaking a nontrivial change to this specification, send mail to themailing list to discuss what you plan to do.This gives everyone a chance to validate the design, helps prevent duplication of effort, and ensures that the idea fits.It also guarantees that the design is sound before code is written; a GitHub pull-request is not the place for high-level discussions.

Typos and grammatical errors can go straight to a pull-request.When in doubt, start on themailing-list.

Please see theOCI org repository README for the most up-to-date information on OCI contributor and maintainer meeting schedules.You can also find links to meeting agendas and minutes for all prior meetings.

You can subscribe and join the mailing list onGoogle Groups.

To keep consistency throughout the Markdown files in the Open Container spec all files should be formatted one sentence per line.This fixes two things: it makes diffing easier with git and it resolves fights about line wrapping length.For example, this paragraph will span three lines in the Markdown source.

The sign-off is a simple line at the end of the explanation for the patch, which certifies that you wrote it or otherwise have the right to pass it on as an open-source patch.The rules are pretty simple: if you can certify the below (fromdevelopercertificate.org):

Developer Certificate of OriginVersion 1.1Copyright (C) 2004, 2006 The Linux Foundation and its contributors.660 York Street, Suite 102,San Francisco, CA 94110 USAEveryone is permitted to copy and distribute verbatim copies of thislicense document, but changing it is not allowed.Developer's Certificate of Origin 1.1By making a contribution to this project, I certify that:(a) The contribution was created in whole or in part by me and I    have the right to submit it under the open source license    indicated in the file; or(b) The contribution is based upon previous work that, to the best    of my knowledge, is covered under an appropriate open source    license and I have the right under that license to submit that    work with modifications, whether created in whole or in part    by me, under the same open source license (unless I am    permitted to submit under a different license), as indicated    in the file; or(c) The contribution was provided directly to me by some other    person who certified (a), (b) or (c) and I have not modified    it.(d) I understand and agree that this project and the contribution    are public and that a record of the contribution (including all    personal information I submit with it, including my sign-off) is    maintained indefinitely and may be redistributed consistent with    this project or the open source license(s) involved.

then you just add a line to every git commit message:

Signed-off-by: Joe Smith <joe@gmail.com>

using your real name (sorry, no pseudonyms or anonymous contributions.)

You can add the sign off when creating the git commit viagit commit -s.

Simple house-keeping for clean git history.Read more onHow to Write a Git Commit Message or the Discussion section ofgit-commit(1).

1. Separate the subject from body with a blank line
2. Limit the subject line to 50 characters
3. Capitalize the subject line
4. Do not end the subject line with a period
5. Use the imperative mood in the subject line
6. Wrap the body at 72 characters
7. Use the body to explain what and why vs. how
   • If there was important/useful/essential conversation or information, copy or include a reference
8. When possible, one keyword to scope the change in the subject (i.e. "README: ...", "runtime: ...")