Enhancements: Re-run initContainers in a Deployment when containers exit on error

[majgis]

Enhancement Description

• One-line enhancement description (can be used as a release note):
  Re-run initContainers in a Deployment when containers exit on error
• Kubernetes Enhancement Proposal: (link to kubernetes/enhancements file, if none yet, link to PR)
  TBD
• Primary contact (assignee):
  TBD
• Responsible SIGs:
  /sig apps
  /sig node
• Enhancement target (which target equals to which milestone):
  TBD
  
  
  
  • Alpha release target (x.y)
  
  
  • Beta release target (x.y)
  
  
  • Stable release target (x.y)
  
  

_Please to keep this description up to date. This will help the Enhancement Team track efficiently the evolution of the enhancement_

[majgis]

A PR still needs to be created for this proposal. If someone else is passionate about this issue, I'm happy to hand off, but I'll continue to pursue it and am currently working on a PR for the enhancements file.

This proposal follows up on an issue that was closed because it was expected to be solved under a different KEP.
The original issue was https://github.com/kubernetes/kubernetes/issues/52345.
It was anticipated the solution would be included in https://github.com/kubernetes/enhancements/blob/master/keps/sig-apps/sidecarcontainers.md .
Why it wasn't included is discussed here: https://github.com/kubernetes/enhancements/issues/691

I see two potential solutions to this problem.
a. Overload existing configuration to allow restarting pod when a container exits, ensuring that initContainers are rerun prior to containers restarting
b. Add new configuration/functionality to associate unique initContainers to specific containers.

Drawbacks and concerns in regard to option a. were discussed in the issue linked to above.
Option b is my own addition, which seems logical and straightforward, but no doubt much more involved to implement.

[justaugustus]

/assign @majgis

[karajas]

I have some questions about the intended design. Would rerunning initContainers on container exit perform a different action that is different from what initContainer would do on startup?

[annajung]

Hello @majgis , 1.17 Enhancement Shadow here! 🙂

I wanted to reach out to see *if this enhancement will be graduating to alpha/beta/stable in 1.17?

*
Please let me know so that this enhancement can be added to 1.17 tracking sheet.

Thank you!

🔔Friendly Reminder

• The current release schedule is
  
  
  
  • Monday, September 23 - Release Cycle Begins
  
  
  • Tuesday, October 15, EOD PST - Enhancements Freeze
  
  
  • Thursday, November 14, EOD PST - Code Freeze
  
  
  • Tuesday, November 19 - Docs must be completed and reviewed
  
  
  • Monday, December 9 - Kubernetes 1.17.0 Released
  
  

• A Kubernetes Enhancement Proposal (KEP) must meet the following criteria before Enhancement Freeze to be accepted into the release

  • PR is merged in
  • In an implementable state
  • Include test plan and graduation criteria

• All relevant k/k PRs should be listed in this issue

[majgis]

I'm unable to contribute at this time. I'm closing the issue to step down. Sorry for the noise and not following through. It was a much desired feature where I worked previously. Anyone still anticipating and willig to carry the torch can reopen or start with a new issue.