linkerd2/pkg/k8s/authz.go

77 lines
1.9 KiB
Go

package k8s
import (
"errors"
"fmt"
authV1 "k8s.io/api/authorization/v1"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/client-go/kubernetes"
)
// ResourceAuthz checks whether a given Kubernetes client is authorized to
// perform a given action.
func ResourceAuthz(
k8sClient kubernetes.Interface,
namespace, verb, group, version, resource, name string,
) error {
ssar := &authV1.SelfSubjectAccessReview{
Spec: authV1.SelfSubjectAccessReviewSpec{
ResourceAttributes: &authV1.ResourceAttributes{
Namespace: namespace,
Verb: verb,
Group: group,
Version: version,
Resource: resource,
Name: name,
},
},
}
result, err := k8sClient.
AuthorizationV1().
SelfSubjectAccessReviews().
Create(ssar)
if err != nil {
return err
}
if result.Status.Allowed {
return nil
}
gk := schema.GroupKind{
Group: group,
Kind: resource,
}
if len(result.Status.Reason) > 0 {
return fmt.Errorf("not authorized to access %s: %s", gk, result.Status.Reason)
}
return fmt.Errorf("not authorized to access %s", gk)
}
// ServiceProfilesAccess checks whether the ServiceProfile CRD is installed
// on the cluster and the client is authorized to access ServiceProfiles.
func ServiceProfilesAccess(k8sClient kubernetes.Interface) error {
res, err := k8sClient.Discovery().ServerResourcesForGroupVersion(ServiceProfileAPIVersion)
if err != nil {
return err
}
if res.GroupVersion == ServiceProfileAPIVersion {
for _, apiRes := range res.APIResources {
if apiRes.Kind == ServiceProfileKind {
return ResourceAuthz(k8sClient, "", "list", "linkerd.io", "", "serviceprofiles", "")
}
}
}
return errors.New("ServiceProfile CRD not found")
}
// ClusterAccess verifies whether k8sClient is authorized to access all pods in
// all namespaces in the cluster.
func ClusterAccess(k8sClient kubernetes.Interface) error {
return ResourceAuthz(k8sClient, "", "list", "", "", "pods", "")
}