kube: plug HostUsers in the pod spec

map HostUsers=false to userns=auto.

One difference with the current implementation in the Kubelet is that
the podman default size is 1024 while the Kubelet uses 65536.

This is done on purpose, because 65536 is a problem for rootless as
the entire IDs space would be allocated to a single pod.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/pkg/k8s.io/api/core/v1/types.go b/pkg/k8s.io/api/core/v1/types.go
index d47178878..6f20cd351 100644
--- a/pkg/k8s.io/api/core/v1/types.go
+++ b/pkg/k8s.io/api/core/v1/types.go
@@ -1984,6 +1984,18 @@ type PodSpec struct {
 	// Default to false.
 	// +optional
 	SetHostnameAsFQDN *bool `json:"setHostnameAsFQDN,omitempty"`
+	// Use the host's user namespace.
+	// Optional: Default to true.
+	// If set to true or not present, the pod will be run in the host user namespace, useful
+	// for when the pod needs a feature only available to the host user namespace, such as
+	// loading a kernel module with CAP_SYS_MODULE.
+	// When set to false, a new userns is created for the pod. Setting false is useful for
+	// mitigating container breakout vulnerabilities even allowing users to run their
+	// containers as root without actually having root privileges on the host.
+	// This field is alpha-level and is only honored by servers that enable the UserNamespacesSupport feature.
+	// +k8s:conversion-gen=false
+	// +optional
+	HostUsers *bool `json:"hostUsers,omitempty"`
 }
 
 type UnsatisfiableConstraintAction string