Kubernetes Rootless mode doesn't honor buildkit-root-volume-memory

[voronin-ilya]

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Description

BuildKit in Kubernetes rootless mode does not use RAM disk for builds when requested.
This code should honor the buildkit-root-volume-memory option and create a volume with "Medium" set to "Memory":

buildx/driver/kubernetes/manifest/manifest.go

Lines 302 to 305 in e540b7a

	d.Spec.Template.Spec.Containers[0].VolumeMounts = append(d.Spec.Template.Spec.Containers[0].VolumeMounts, corev1.VolumeMount{
	Name: emptyDirVolName,
	MountPath: "/home/user/.local/share/buildkit",
	})

Expected behaviour

When buildkit-root-volume-memory is configured, builds should occur on RAM disk, even in rootless mode.

Actual behaviour

When running BuildKit in rootless mode, /var/lib/buildkit is not used. Instead, data is stored in the non-root user's home directory. This causes image builds to hit the file system instead of memory, even when buildkit-root-volume-memory is set.

Buildx version

github.com/docker/buildx v0.27.0 bac71de

Docker info

Builders list

kubernetes

Configuration

Build logs

Additional info

No response