Feature Overview (aka. Goal Summary)  

Provide a long term solution to SELinux context labeling in OCP. Continue the implementation with RWO/RWX PVs which are the most expected from the field. Start with a TechPreview support grade.

Goals (aka. expected user outcomes)

As of today when selinux is enabled, the PV's files are relabeled when attaching the PV to the pod, this can cause timeout when the PVs contains lot of files as well as overloading the storage backend.

https://access.redhat.com/solutions/6221251 provides few workarounds until the proper fix is implemented. Unfortunately these workaround are not perfect and we need a long term seamless optimised solution.

This feature tracks the long term solution where the PV FS will be mounted with the right selinux context thus avoiding to relabel every file. This covers RWO/RWX PVs, RWOP is already being implemented and should GA in 4.17.

Requirements (aka. Acceptance Criteria):

Should pass all regular regression CI. All the drivers we ship should have it enabled and partners may enable it if they want it to be consumed.

Performances should drascillaly improved and security should remain the same as the legacy chcon approach.

Use Cases (Optional):

Provide details for user scenarios including actions to be performed, platform specifications, and user personas.  

1. Apply new context when there is none
2. Change context of all files/folders when changing context
3. RWO & RWX PVs

As we are relying on mount context there should not be any relabeling (chcon) because all files / folders will inherit the context from the mount context

More on design & scenarios in the KEP

Out of Scope

RWOP PVs

Background

Lots of support cases due to pod taking too long to start because of selinux relabeling with chcon. This epics covers the most "unpopular" RWX case specially for PVs with lots of files and backends that are "slow" at updating metadata.

Customer Considerations

Most cases / concerns are on RWX, RWOP was the first step and has limited customer's impact though it is easier to implement first and gather feedback / metrics. https://access.redhat.com/solutions/6221251

This feature track TP for RWO/RWX PVs

Documentation Considerations

Relnotes + table of drivers supporting it.

Interoperability Considerations

Partners may want to enable the feature.