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== User Experience ==
== User Experience ==
<!-- If this change proposal is noticeable by users, how will their experiences change as a result?
Users should experience a nice improvement in download speeds of container images that were previously created with zstd:chunked.
 
This section partially overlaps with the Benefit to Fedora section above. This section should be primarily about the User Experience, written in a way that does not assume deep technical knowledge. More detailed technical description should be left for the Benefit to Fedora section.
 
Describe what Users will see or notice, for example:
  - Packages are compressed more efficiently, making downloads and upgrades faster by 10%.
  - Kerberos tickets can be renewed automatically. Users will now have to authenticate less and become more productive. Credential management improvements mean a user can start their work day with a single sign on and not have to pause for reauthentication during their entire day.
- Libreoffice is one of the most commonly installed applications on Fedora and it is now available by default to help users "hit the ground running".
- Green has been scientifically proven to be the most relaxing color. The move to a default background color of green with green text will result in Fedora users being the most relaxed users of any operating system.
-->


== Dependencies ==
== Dependencies ==

Revision as of 15:55, 31 October 2023


Change Proposal Name

This is a proposed Change for Fedora Linux.
This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee.

Summary

Modify podman push to default to creating images with zstd:chunked, allowing users to modify containers.conf to continue to use the legacy gzip image format.

Owner

Current status

  • Targeted release: Fedora Linux 40
  • Last updated: 2023-10-31
  • [<will be assigned by the Wrangler> devel thread]
  • FESCo issue: <will be assigned by the Wrangler>
  • Tracker bug: <will be assigned by the Wrangler>
  • Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

The goal is to speed up the pulling of container images, via using zstd:chunked. zstd:chunked format has shown itself to speed up the pulling of images by as much as 90%. This change has been waiting for change for over 3 years, waiting for Docker to support the format.

Feedback

Benefit to Fedora

Fedora would be the first distribution to support building zstd:chunked format by default. Container engines (Podman, Buildah, Skopeo, CRI-O) which support the format natively would see a great speed up in pulling images. Other container engines including Docker and Containerd would see some speed up do the the compression algorythms of zstd, but not to the same degree as container engines with full support.

Scope

  • Proposal owners:
  • Other developers:
  • Policies and guidelines: N/A (not needed for this Change)
  • Trademark approval: N/A (not needed for this Change)
  • Alignment with Community Initiatives:

Upgrade/compatibility impact

How To Test

Build and push container images to container registries. Inspect them to check that their format is zstd:chunked. Pull the image back to the host. Now make a small change to the image and push it back to the registry Remove the changed image leaving the original image in place. Now pull the updated image again. You should see a big change in download speed.

Now attempt to pull the same image with Docker/Moby to make sure the image works with those container engines.

User Experience

Users should experience a nice improvement in download speeds of container images that were previously created with zstd:chunked.

Dependencies

Contingency Plan

  • Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change)
  • Contingency deadline: N/A (not a System Wide Change)
  • Blocks release? N/A (not a System Wide Change), Yes/No


Documentation

N/A (not a System Wide Change)

Release Notes