|
| 1 | +package podsecurity |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "fmt" |
| 6 | + |
| 7 | + utilruntime "k8s.io/apimachinery/pkg/util/runtime" |
| 8 | + |
| 9 | + corev1 "k8s.io/api/core/v1" |
| 10 | + "k8s.io/apimachinery/pkg/api/meta" |
| 11 | + metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| 12 | + "k8s.io/apimachinery/pkg/runtime" |
| 13 | + "k8s.io/apimachinery/pkg/runtime/schema" |
| 14 | + "k8s.io/apiserver/pkg/admission" |
| 15 | + "k8s.io/apiserver/pkg/authentication/serviceaccount" |
| 16 | + "k8s.io/apiserver/pkg/authentication/user" |
| 17 | + "k8s.io/klog/v2" |
| 18 | + "k8s.io/kubernetes/pkg/apis/core" |
| 19 | + v1 "k8s.io/kubernetes/pkg/apis/core/v1" |
| 20 | + saadmission "k8s.io/kubernetes/plugin/pkg/admission/serviceaccount" |
| 21 | + podsecurityadmission "k8s.io/pod-security-admission/admission" |
| 22 | +) |
| 23 | + |
| 24 | +type SCCMutatingPodSpecExtractor struct { |
| 25 | + sccAdmission admission.MutationInterface |
| 26 | + delegate podsecurityadmission.PodSpecExtractor |
| 27 | +} |
| 28 | + |
| 29 | +var SCCMutatingPodSpecExtractorInstance = &SCCMutatingPodSpecExtractor{ |
| 30 | + delegate: podsecurityadmission.DefaultPodSpecExtractor{}, |
| 31 | +} |
| 32 | + |
| 33 | +func (s *SCCMutatingPodSpecExtractor) SetSCCAdmission(sccAdmission admission.MutationInterface) { |
| 34 | + s.sccAdmission = sccAdmission |
| 35 | +} |
| 36 | + |
| 37 | +func (s *SCCMutatingPodSpecExtractor) HasPodSpec(gr schema.GroupResource) bool { |
| 38 | + return s.delegate.HasPodSpec(gr) |
| 39 | +} |
| 40 | + |
| 41 | +func (s *SCCMutatingPodSpecExtractor) ExtractPodSpec(obj runtime.Object) (*metav1.ObjectMeta, *corev1.PodSpec, error) { |
| 42 | + if s.sccAdmission == nil { |
| 43 | + return s.delegate.ExtractPodSpec(obj) |
| 44 | + } |
| 45 | + |
| 46 | + switch obj := obj.(type) { |
| 47 | + case *corev1.Pod: |
| 48 | + return s.delegate.ExtractPodSpec(obj) |
| 49 | + } |
| 50 | + |
| 51 | + podTemplateMeta, originalPodSpec, err := s.delegate.ExtractPodSpec(obj) |
| 52 | + if err != nil { |
| 53 | + return podTemplateMeta, originalPodSpec, err |
| 54 | + } |
| 55 | + if originalPodSpec == nil { |
| 56 | + return nil, nil, nil |
| 57 | + } |
| 58 | + objectMeta, err := meta.Accessor(obj) |
| 59 | + if err != nil { |
| 60 | + return podTemplateMeta, originalPodSpec, fmt.Errorf("unable to get metadata for SCC mutation: %w", err) |
| 61 | + } |
| 62 | + |
| 63 | + pod := &corev1.Pod{ |
| 64 | + ObjectMeta: *podTemplateMeta.DeepCopy(), |
| 65 | + Spec: *originalPodSpec.DeepCopy(), |
| 66 | + } |
| 67 | + if len(pod.Namespace) == 0 { |
| 68 | + pod.Namespace = objectMeta.GetNamespace() |
| 69 | + } |
| 70 | + if len(pod.Name) == 0 { |
| 71 | + pod.Name = "pod-for-container-named-" + objectMeta.GetName() |
| 72 | + } |
| 73 | + if len(pod.Spec.ServiceAccountName) == 0 { |
| 74 | + pod.Spec.ServiceAccountName = saadmission.DefaultServiceAccountName |
| 75 | + } |
| 76 | + internalPod := &core.Pod{} |
| 77 | + if err := v1.Convert_v1_Pod_To_core_Pod(pod, internalPod, nil); err != nil { |
| 78 | + return nil, nil, err |
| 79 | + } |
| 80 | + |
| 81 | + admissionAttributes := admission.NewAttributesRecord( |
| 82 | + internalPod, |
| 83 | + nil, |
| 84 | + corev1.SchemeGroupVersion.WithKind("Pod"), |
| 85 | + pod.Namespace, |
| 86 | + pod.Name, |
| 87 | + corev1.SchemeGroupVersion.WithResource("pods"), |
| 88 | + "", |
| 89 | + admission.Create, |
| 90 | + nil, |
| 91 | + false, |
| 92 | + &user.DefaultInfo{ |
| 93 | + Name: serviceaccount.MakeUsername(pod.Namespace, pod.Spec.ServiceAccountName), |
| 94 | + UID: "", |
| 95 | + Groups: append([]string{user.AllAuthenticated}, serviceaccount.MakeGroupNames(pod.Namespace)...), |
| 96 | + Extra: nil, |
| 97 | + }) |
| 98 | + if err := s.sccAdmission.Admit(context.Background(), admissionAttributes, nil); err != nil { |
| 99 | + // don't fail the request, just warn if SCC will fail |
| 100 | + klog.ErrorS(err, "failed to mutate object for PSA using SCC") |
| 101 | + utilruntime.HandleError(fmt.Errorf("failed to mutate object for PSA using SCC: %w", err)) |
| 102 | + // TODO remove this failure we're causing when SCC fails, but for now we actually need to see our test fail because that was almost really bad. |
| 103 | + return podTemplateMeta, originalPodSpec, nil |
| 104 | + } |
| 105 | + |
| 106 | + if err := v1.Convert_core_Pod_To_v1_Pod(internalPod, pod, nil); err != nil { |
| 107 | + return nil, nil, err |
| 108 | + } |
| 109 | + |
| 110 | + return podTemplateMeta, &pod.Spec, nil |
| 111 | +} |
0 commit comments