Refactor PSP provider

This commit is contained in:
Tim Allclair 2019-03-25 11:01:28 -07:00
parent 939f8ffa87
commit e5d2cad7b9
4 changed files with 79 additions and 77 deletions

View File

@ -59,10 +59,10 @@ func NewSimpleProvider(psp *policy.PodSecurityPolicy, namespace string, strategy
}, nil
}
// DefaultPodSecurityContext sets the default values of the required but not filled fields.
// It modifies the SecurityContext and annotations of the provided pod. Validation should be
// used after the context is defaulted to ensure it complies with the required restrictions.
func (s *simpleProvider) DefaultPodSecurityContext(pod *api.Pod) error {
// MutatePod sets the default values of the required but not filled fields.
// Validation should be used after the context is defaulted to ensure it
// complies with the required restrictions.
func (s *simpleProvider) MutatePod(pod *api.Pod) error {
sc := securitycontext.NewPodSecurityContextMutator(pod.Spec.SecurityContext)
if sc.SupplementalGroups() == nil {
@ -104,13 +104,25 @@ func (s *simpleProvider) DefaultPodSecurityContext(pod *api.Pod) error {
pod.Spec.SecurityContext = sc.PodSecurityContext()
for i := range pod.Spec.InitContainers {
if err := s.mutateContainer(pod, &pod.Spec.InitContainers[i]); err != nil {
return err
}
}
for i := range pod.Spec.Containers {
if err := s.mutateContainer(pod, &pod.Spec.Containers[i]); err != nil {
return err
}
}
return nil
}
// DefaultContainerSecurityContext sets the default values of the required but not filled fields.
// mutateContainer sets the default values of the required but not filled fields.
// It modifies the SecurityContext of the container and annotations of the pod. Validation should
// be used after the context is defaulted to ensure it complies with the required restrictions.
func (s *simpleProvider) DefaultContainerSecurityContext(pod *api.Pod, container *api.Container) error {
func (s *simpleProvider) mutateContainer(pod *api.Pod, container *api.Container) error {
sc := securitycontext.NewEffectiveContainerSecurityContextMutator(
securitycontext.NewPodSecurityContextAccessor(pod.Spec.SecurityContext),
securitycontext.NewContainerSecurityContextMutator(container.SecurityContext),
@ -282,11 +294,22 @@ func (s *simpleProvider) ValidatePod(pod *api.Pod) field.ErrorList {
}
}
}
fldPath := field.NewPath("spec", "initContainers")
for i := range pod.Spec.InitContainers {
allErrs = append(allErrs, s.validateContainer(pod, &pod.Spec.InitContainers[i], fldPath.Index(i))...)
}
fldPath = field.NewPath("spec", "containers")
for i := range pod.Spec.Containers {
allErrs = append(allErrs, s.validateContainer(pod, &pod.Spec.Containers[i], fldPath.Index(i))...)
}
return allErrs
}
// Ensure a container's SecurityContext is in compliance with the given constraints
func (s *simpleProvider) ValidateContainer(pod *api.Pod, container *api.Container, containerPath *field.Path) field.ErrorList {
func (s *simpleProvider) validateContainer(pod *api.Pod, container *api.Container, containerPath *field.Path) field.ErrorList {
allErrs := field.ErrorList{}
podSC := securitycontext.NewPodSecurityContextAccessor(pod.Spec.SecurityContext)

View File

@ -31,7 +31,6 @@ import (
policy "k8s.io/api/policy/v1beta1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/diff"
"k8s.io/apimachinery/pkg/util/validation/field"
api "k8s.io/kubernetes/pkg/apis/core"
k8s_api_v1 "k8s.io/kubernetes/pkg/apis/core/v1"
"k8s.io/kubernetes/pkg/security/apparmor"
@ -41,7 +40,7 @@ import (
const defaultContainerName = "test-c"
func TestDefaultPodSecurityContextNonmutating(t *testing.T) {
func TestMutatePodNonmutating(t *testing.T) {
// Create a pod with a security context that needs filling in
createPod := func() *api.Pod {
return &api.Pod{
@ -89,7 +88,7 @@ func TestDefaultPodSecurityContextNonmutating(t *testing.T) {
if err != nil {
t.Fatalf("unable to create provider %v", err)
}
err = provider.DefaultPodSecurityContext(pod)
err = provider.MutatePod(pod)
if err != nil {
t.Fatalf("unable to create psc %v", err)
}
@ -98,14 +97,14 @@ func TestDefaultPodSecurityContextNonmutating(t *testing.T) {
// since all the strategies were permissive
if !reflect.DeepEqual(createPod(), pod) {
diffs := diff.ObjectDiff(createPod(), pod)
t.Errorf("pod was mutated by DefaultPodSecurityContext. diff:\n%s", diffs)
t.Errorf("pod was mutated by MutatePod. diff:\n%s", diffs)
}
if !reflect.DeepEqual(createPSP(), psp) {
t.Error("psp was mutated by DefaultPodSecurityContext")
t.Error("psp was mutated by MutatePod")
}
}
func TestDefaultContainerSecurityContextNonmutating(t *testing.T) {
func TestMutateContainerNonmutating(t *testing.T) {
untrue := false
tests := []struct {
security *api.SecurityContext
@ -134,7 +133,6 @@ func TestDefaultContainerSecurityContextNonmutating(t *testing.T) {
Name: "psp-sa",
Annotations: map[string]string{
seccomp.AllowedProfilesAnnotationKey: "*",
seccomp.DefaultProfileAnnotationKey: "foo",
},
},
Spec: policy.PodSecurityPolicySpec{
@ -165,7 +163,7 @@ func TestDefaultContainerSecurityContextNonmutating(t *testing.T) {
if err != nil {
t.Fatalf("unable to create provider %v", err)
}
err = provider.DefaultContainerSecurityContext(pod, &pod.Spec.Containers[0])
err = provider.MutatePod(pod)
if err != nil {
t.Fatalf("unable to create container security context %v", err)
}
@ -174,15 +172,15 @@ func TestDefaultContainerSecurityContextNonmutating(t *testing.T) {
// since all the strategies were permissive
if !reflect.DeepEqual(createPod(), pod) {
diffs := diff.ObjectDiff(createPod(), pod)
t.Errorf("pod was mutated by DefaultContainerSecurityContext. diff:\n%s", diffs)
t.Errorf("pod was mutated. diff:\n%s", diffs)
}
if !reflect.DeepEqual(createPSP(), psp) {
t.Error("psp was mutated by DefaultContainerSecurityContext")
t.Error("psp was mutated")
}
}
}
func TestValidatePodSecurityContextFailures(t *testing.T) {
func TestValidatePodFailures(t *testing.T) {
failHostNetworkPod := defaultPod()
failHostNetworkPod.Spec.SecurityContext.HostNetwork = true
@ -504,6 +502,7 @@ func TestValidateContainerFailures(t *testing.T) {
},
}
failSELinuxPod := defaultPod()
failSELinuxPod.Spec.SecurityContext.SELinuxOptions = &api.SELinuxOptions{Level: "foo"}
failSELinuxPod.Spec.Containers[0].SecurityContext.SELinuxOptions = &api.SELinuxOptions{
Level: "bar",
}
@ -620,22 +619,24 @@ func TestValidateContainerFailures(t *testing.T) {
}
for k, v := range errorCases {
t.Run(k, func(t *testing.T) {
provider, err := NewSimpleProvider(v.psp, "namespace", NewSimpleStrategyFactory())
if err != nil {
t.Fatalf("unable to create provider %v", err)
}
errs := provider.ValidateContainer(v.pod, &v.pod.Spec.Containers[0], field.NewPath(""))
errs := provider.ValidatePod(v.pod)
if len(errs) == 0 {
t.Errorf("%s expected validation failure but did not receive errors", k)
continue
t.Errorf("expected validation failure but did not receive errors")
return
}
if !strings.Contains(errs[0].Error(), v.expectedError) {
t.Errorf("%s received unexpected error %v\nexpected: %s", k, errs, v.expectedError)
t.Errorf("unexpected error %v\nexpected: %s", errs, v.expectedError)
}
})
}
}
func TestValidatePodSecurityContextSuccess(t *testing.T) {
func TestValidatePodSuccess(t *testing.T) {
hostNetworkPSP := defaultPSP()
hostNetworkPSP.Spec.HostNetwork = true
hostNetworkPod := defaultPod()
@ -941,6 +942,7 @@ func TestValidateContainerSuccess(t *testing.T) {
},
}
seLinuxPod := defaultPod()
seLinuxPod.Spec.SecurityContext.SELinuxOptions = &api.SELinuxOptions{Level: "foo"}
seLinuxPod.Spec.Containers[0].SecurityContext.SELinuxOptions = &api.SELinuxOptions{
Level: "foo",
}
@ -1007,6 +1009,7 @@ func TestValidateContainerSuccess(t *testing.T) {
seccompPod := defaultPod()
seccompPod.Annotations = map[string]string{
api.SeccompPodAnnotationKey: "foo",
api.SeccompContainerAnnotationKeyPrefix + seccompPod.Spec.Containers[0].Name: "foo",
}
@ -1074,15 +1077,16 @@ func TestValidateContainerSuccess(t *testing.T) {
}
for k, v := range successCases {
t.Run(k, func(t *testing.T) {
provider, err := NewSimpleProvider(v.psp, "namespace", NewSimpleStrategyFactory())
if err != nil {
t.Fatalf("unable to create provider %v", err)
}
errs := provider.ValidateContainer(v.pod, &v.pod.Spec.Containers[0], field.NewPath(""))
errs := provider.ValidatePod(v.pod)
if len(errs) != 0 {
t.Errorf("%s expected validation pass but received errors %v\n%s", k, errs, spew.Sdump(v.pod.ObjectMeta))
continue
}
})
}
}
@ -1146,7 +1150,7 @@ func TestGenerateContainerSecurityContextReadOnlyRootFS(t *testing.T) {
t.Errorf("%s unable to create provider %v", k, err)
continue
}
err = provider.DefaultContainerSecurityContext(v.pod, &v.pod.Spec.Containers[0])
err = provider.MutatePod(v.pod)
if err != nil {
t.Errorf("%s unable to create container security context %v", k, err)
continue
@ -1351,10 +1355,10 @@ func TestAllowPrivilegeEscalation(t *testing.T) {
provider, err := NewSimpleProvider(psp, "namespace", NewSimpleStrategyFactory())
require.NoError(t, err)
err = provider.DefaultContainerSecurityContext(pod, &pod.Spec.Containers[0])
err = provider.MutatePod(pod)
require.NoError(t, err)
errs := provider.ValidateContainer(pod, &pod.Spec.Containers[0], field.NewPath(""))
errs := provider.ValidatePod(pod)
if test.expectErr {
assert.NotEmpty(t, errs, "expected validation error")
} else {

View File

@ -32,16 +32,12 @@ import (
// Provider provides the implementation to generate a new security
// context based on constraints or validate an existing security context against constraints.
type Provider interface {
// DefaultPodSecurityContext sets the default values of the required but not filled fields.
// It modifies the SecurityContext and annotations of the provided pod.
DefaultPodSecurityContext(pod *api.Pod) error
// DefaultContainerSecurityContext sets the default values of the required but not filled fields.
// It modifies the SecurityContext of the container and annotations of the pod.
DefaultContainerSecurityContext(pod *api.Pod, container *api.Container) error
// Ensure a pod is in compliance with the given constraints.
// MutatePod sets the default values of the required but not filled fields of the pod and all
// containers in the pod.
MutatePod(pod *api.Pod) error
// ValidatePod ensures a pod and all its containers are in compliance with the given constraints.
// ValidatePod MUST NOT mutate the pod.
ValidatePod(pod *api.Pod) field.ErrorList
// Ensure a container's SecurityContext is in compliance with the given constraints.
ValidateContainer(pod *api.Pod, container *api.Container, containerPath *field.Path) field.ErrorList
// Get the name of the PSP that this provider was initialized with.
GetPSPName() string
}

View File

@ -306,35 +306,14 @@ func (c *PodSecurityPolicyPlugin) computeSecurityContext(a admission.Attributes,
func assignSecurityContext(provider psp.Provider, pod *api.Pod) field.ErrorList {
errs := field.ErrorList{}
err := provider.DefaultPodSecurityContext(pod)
if err != nil {
errs = append(errs, field.Invalid(field.NewPath("spec", "securityContext"), pod.Spec.SecurityContext, err.Error()))
if err := provider.MutatePod(pod); err != nil {
// TODO(tallclair): MutatePod should return a field.ErrorList
errs = append(errs, field.Invalid(field.NewPath(""), pod, err.Error()))
}
errs = append(errs, provider.ValidatePod(pod)...)
for i := range pod.Spec.InitContainers {
err := provider.DefaultContainerSecurityContext(pod, &pod.Spec.InitContainers[i])
if err != nil {
errs = append(errs, field.Invalid(field.NewPath("spec", "initContainers").Index(i).Child("securityContext"), "", err.Error()))
continue
}
errs = append(errs, provider.ValidateContainer(pod, &pod.Spec.InitContainers[i], field.NewPath("spec", "initContainers").Index(i))...)
}
for i := range pod.Spec.Containers {
err := provider.DefaultContainerSecurityContext(pod, &pod.Spec.Containers[i])
if err != nil {
errs = append(errs, field.Invalid(field.NewPath("spec", "containers").Index(i).Child("securityContext"), "", err.Error()))
continue
}
errs = append(errs, provider.ValidateContainer(pod, &pod.Spec.Containers[i], field.NewPath("spec", "containers").Index(i))...)
}
if len(errs) > 0 {
return errs
}
return nil
}
// createProvidersFromPolicies creates providers from the constraints supplied.