[MESOS-7306] Support mount propagation for host volumes.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.5.0
• Component/s: containerization
• Labels: mesosphere storage
• Epic Link: Resource Provider and CSI
• Sprint: Mesosphere Sprint 62, Mesosphere Sprint 63, Mesosphere Sprint 64, Mesosphere Sprint 66, Mesosphere Sprint 67, Mesosphere Sprint 68, Mesosphere Sprint 69
• Story Points: 8
• Assignee: Jie Yu
• Reporter: Jie Yu
• Created: 24/Mar/17 20:35
• Updated: 29/Nov/17 03:38
• Resolved: 29/Nov/17 03:38

Description

Currently, all mounts in a container are marked as 'slave' by default. However, for some cases, we may want mounts under certain directory in a container to be propagate back to the root mount namespace. This is useful for the case where we want the mounts to survive container failures.

See more documentation about mount propagation in:
https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt

Given mount propagation is very hard for users to understand, probably worth limiting this to just host volumes because we only see use case for that at the moment.

Some relevant discussion can be found here:
https://github.com/kubernetes/community/blob/master/contributors/design-proposals/propagation.md