PodSecurity: seccompProfile_restricted: cleanup

Switch from field paths to container names in messages
Add unit tests for messages
Consolidate integration test fixtures

staging/src/k8s.io/pod-security-admission/policy/check_seccompProfile_restricted.go

@@ -0,0 +1,138 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package policy
+
+import (
+	"fmt"
+	"strings"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/pod-security-admission/api"
+)
+
+/*
+
+Seccomp profiles must be specified, and only runtime default and localhost profiles are allowed.
+
+v1.19+:
+**Restricted Fields:**
+spec.securityContext.seccompProfile.type
+spec.containers[*].securityContext.seccompProfile.type
+spec.initContainers[*].securityContext.seccompProfile.type
+
+**Allowed Values:** 'RuntimeDefault', 'Localhost'
+Note: container-level fields may be undefined if pod-level field is specified.
+
+*/
+
+func init() {
+	addCheck(CheckSeccompProfileRestricted)
+}
+
+func CheckSeccompProfileRestricted() Check {
+	return Check{
+		ID:    "seccompProfile_restricted",
+		Level: api.LevelRestricted,
+		Versions: []VersionedCheck{
+			{
+				MinimumVersion: api.MajorMinorVersion(1, 19),
+				CheckPod:       seccompProfileRestricted_1_19,
+			},
+		},
+	}
+}
+
+// seccompProfileRestricted_1_19 checks restricted policy on securityContext.seccompProfile field
+func seccompProfileRestricted_1_19(podMetadata *metav1.ObjectMeta, podSpec *corev1.PodSpec) CheckResult {
+	// things that explicitly set seccompProfile.type to a bad value
+	var badSetters []string
+	badValues := sets.NewString()
+
+	podSeccompSet := false
+
+	if podSpec.SecurityContext != nil && podSpec.SecurityContext.SeccompProfile != nil {
+		if !validSeccomp(podSpec.SecurityContext.SeccompProfile.Type) {
+			badSetters = append(badSetters, "pod")
+			badValues.Insert(string(podSpec.SecurityContext.SeccompProfile.Type))
+		} else {
+			podSeccompSet = true
+		}
+	}
+
+	// containers that explicitly set seccompProfile.type to a bad value
+	var explicitlyBadContainers []string
+	// containers that didn't set seccompProfile and aren't caught by a pod-level seccompProfile
+	var implicitlyBadContainers []string
+
+	visitContainersWithPath(podSpec, field.NewPath("spec"), func(c *corev1.Container, path *field.Path) {
+		if c.SecurityContext != nil && c.SecurityContext.SeccompProfile != nil {
+			// container explicitly set seccompProfile
+			if !validSeccomp(c.SecurityContext.SeccompProfile.Type) {
+				// container explicitly set seccompProfile to a bad value
+				explicitlyBadContainers = append(explicitlyBadContainers, c.Name)
+				badValues.Insert(string(c.SecurityContext.SeccompProfile.Type))
+			}
+		} else {
+			// container did not explicitly set seccompProfile
+			if !podSeccompSet {
+				// no valid pod-level seccompProfile, so this container implicitly has a bad value
+				implicitlyBadContainers = append(implicitlyBadContainers, c.Name)
+			}
+		}
+	})
+
+	if len(explicitlyBadContainers) > 0 {
+		badSetters = append(
+			badSetters,
+			fmt.Sprintf(
+				"%s %s",
+				pluralize("container", "containers", len(explicitlyBadContainers)),
+				joinQuote(explicitlyBadContainers),
+			),
+		)
+	}
+	// pod or containers explicitly set bad seccompProfiles
+	if len(badSetters) > 0 {
+		return CheckResult{
+			Allowed:         false,
+			ForbiddenReason: "seccompProfile",
+			ForbiddenDetail: fmt.Sprintf(
+				"%s must not set securityContext.seccompProfile.type to %s",
+				strings.Join(badSetters, " and "),
+				joinQuote(badValues.List()),
+			),
+		}
+	}
+
+	// pod didn't set seccompProfile and not all containers opted into seccompProfile
+	if len(implicitlyBadContainers) > 0 {
+		return CheckResult{
+			Allowed:         false,
+			ForbiddenReason: "seccompProfile",
+			ForbiddenDetail: fmt.Sprintf(
+				`pod or %s %s must set securityContext.seccompProfile.type to "RuntimeDefault" or "Localhost"`,
+				pluralize("container", "containers", len(implicitlyBadContainers)),
+				joinQuote(implicitlyBadContainers),
+			),
+		}
+	}
+
+	return CheckResult{Allowed: true}
+}

staging/src/k8s.io/pod-security-admission/policy/check_seccompProfile_restricted_test.go

@@ -0,0 +1,98 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package policy
+
+import (
+	"testing"
+
+	corev1 "k8s.io/api/core/v1"
+)
+
+func TestSeccompProfileRestricted(t *testing.T) {
+	tests := []struct {
+		name         string
+		pod          *corev1.Pod
+		expectReason string
+		expectDetail string
+	}{
+		{
+			name: "no explicit seccomp",
+			pod: &corev1.Pod{Spec: corev1.PodSpec{
+				Containers: []corev1.Container{
+					{Name: "a"},
+				},
+			}},
+			expectReason: `seccompProfile`,
+			expectDetail: `pod or container "a" must set securityContext.seccompProfile.type to "RuntimeDefault" or "Localhost"`,
+		},
+		{
+			name: "pod seccomp invalid",
+			pod: &corev1.Pod{Spec: corev1.PodSpec{
+				SecurityContext: &corev1.PodSecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeUnconfined}},
+				Containers: []corev1.Container{
+					{Name: "a", SecurityContext: nil},
+				},
+			}},
+			expectReason: `seccompProfile`,
+			expectDetail: `pod must not set securityContext.seccompProfile.type to "Unconfined"`,
+		},
+		{
+			name: "containers seccomp invalid",
+			pod: &corev1.Pod{Spec: corev1.PodSpec{
+				SecurityContext: &corev1.PodSecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeRuntimeDefault}},
+				Containers: []corev1.Container{
+					{Name: "a", SecurityContext: nil},
+					{Name: "b", SecurityContext: &corev1.SecurityContext{}},
+					{Name: "c", SecurityContext: &corev1.SecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeUnconfined}}},
+					{Name: "d", SecurityContext: &corev1.SecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeUnconfined}}},
+					{Name: "e", SecurityContext: &corev1.SecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeRuntimeDefault}}},
+					{Name: "f", SecurityContext: &corev1.SecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeRuntimeDefault}}},
+				},
+			}},
+			expectReason: `seccompProfile`,
+			expectDetail: `containers "c", "d" must not set securityContext.seccompProfile.type to "Unconfined"`,
+		},
+		{
+			name: "pod nil, container fallthrough",
+			pod: &corev1.Pod{Spec: corev1.PodSpec{
+				Containers: []corev1.Container{
+					{Name: "a", SecurityContext: nil},
+					{Name: "b", SecurityContext: &corev1.SecurityContext{}},
+					{Name: "d", SecurityContext: &corev1.SecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeRuntimeDefault}}},
+					{Name: "e", SecurityContext: &corev1.SecurityContext{SeccompProfile: &corev1.SeccompProfile{Type: corev1.SeccompProfileTypeRuntimeDefault}}},
+				},
+			}},
+			expectReason: `seccompProfile`,
+			expectDetail: `pod or containers "a", "b" must set securityContext.seccompProfile.type to "RuntimeDefault" or "Localhost"`,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result := seccompProfileRestricted_1_19(&tc.pod.ObjectMeta, &tc.pod.Spec)
+			if result.Allowed {
+				t.Fatal("expected disallowed")
+			}
+			if e, a := tc.expectReason, result.ForbiddenReason; e != a {
+				t.Errorf("expected\n%s\ngot\n%s", e, a)
+			}
+			if e, a := tc.expectDetail, result.ForbiddenDetail; e != a {
+				t.Errorf("expected\n%s\ngot\n%s", e, a)
+			}
+		})
+	}
+}

staging/src/k8s.io/pod-security-admission/policy/check_seccomp_restricted.go

@@ -1,88 +0,0 @@
-/*
-Copyright 2021 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package policy
-
-import (
-	"strings"
-
-	corev1 "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/apimachinery/pkg/util/validation/field"
-	"k8s.io/pod-security-admission/api"
-)
-
-func init() {
-	addCheck(CheckSeccompRestricted)
-}
-
-func CheckSeccompRestricted() Check {
-	return Check{
-		ID:    "seccomp_restricted",
-		Level: api.LevelRestricted,
-		Versions: []VersionedCheck{
-			{
-				MinimumVersion: api.MajorMinorVersion(1, 19),
-				CheckPod:       seccomp_1_19_restricted,
-			},
-		},
-	}
-}
-
-// seccomp_1_19_restricted checks restricted policy on securityContext.seccompProfile field
-func seccomp_1_19_restricted(podMetadata *metav1.ObjectMeta, podSpec *corev1.PodSpec) CheckResult {
-	forbidden := sets.NewString()
-	podSeccompField := field.NewPath("spec").Child("securityContext", "seccompProfile", "type")
-	podSeccompSet := false
-
-	if podSpec.SecurityContext != nil {
-		if podSpec.SecurityContext.SeccompProfile != nil {
-			seccompType := podSpec.SecurityContext.SeccompProfile.Type
-			if !validSeccomp(podSpec.SecurityContext.SeccompProfile.Type) {
-				forbidden.Insert(fieldValue(podSeccompField, string(seccompType)))
-			} else {
-				podSeccompSet = true
-			}
-		}
-	}
-
-	visitContainersWithPath(podSpec, field.NewPath("spec"), func(c *corev1.Container, path *field.Path) {
-		if c.SecurityContext != nil && c.SecurityContext.SeccompProfile != nil {
-			seccompType := c.SecurityContext.SeccompProfile.Type
-			if !validSeccomp(seccompType) {
-				containerSeccompField := path.Child("securityContext", "seccompProfile", "type")
-				forbidden.Insert(fieldValue(containerSeccompField, string(seccompType)))
-			}
-			return
-		}
-
-		if !podSeccompSet {
-			containerSeccompField := path.Child("securityContext", "seccompProfile", "type")
-			forbidden.Insert(fieldValueRequired(containerSeccompField))
-		}
-	})
-
-	if len(forbidden) > 0 {
-		return CheckResult{
-			Allowed:         false,
-			ForbiddenReason: "seccomp profile",
-			ForbiddenDetail: strings.Join(forbidden.List(), ", "),
-		}
-	}
-
-	return CheckResult{Allowed: true}
-}

staging/src/k8s.io/pod-security-admission/test/fixtures_seccompProfile_restricted.go

@@ -30,7 +30,7 @@ The check implementation looks at the appropriate value based on version.
 
 func init() {
 	fixtureData_restricted_1_19 := fixtureGenerator{
-		expectErrorSubstring: "seccomp profile",
+		expectErrorSubstring: "seccompProfile",
 		generatePass: func(p *corev1.Pod) []*corev1.Pod {
 			p = ensureSecurityContext(p)
 			return []*corev1.Pod{
@@ -43,11 +43,6 @@ func init() {
 				tweak(p, func(p *corev1.Pod) {
 					p.Spec.SecurityContext.SeccompProfile = nil
 					p.Spec.Containers[0].SecurityContext.SeccompProfile = seccompProfileRuntimeDefault
-					p.Spec.InitContainers[0].SecurityContext.SeccompProfile = seccompProfileRuntimeDefault
-				}),
-				tweak(p, func(p *corev1.Pod) {
-					p.Spec.SecurityContext.SeccompProfile = nil
-					p.Spec.Containers[0].SecurityContext.SeccompProfile = seccompProfileLocalhost("testing")
 					p.Spec.InitContainers[0].SecurityContext.SeccompProfile = seccompProfileLocalhost("testing")
 				}),
 			}
@@ -55,36 +50,36 @@ func init() {
 		generateFail: func(p *corev1.Pod) []*corev1.Pod {
 			p = ensureSecurityContext(p)
 			return []*corev1.Pod{
+				// unset everywhere
 				tweak(p, func(p *corev1.Pod) {
 					p.Spec.SecurityContext.SeccompProfile = nil
 				}),
+				// unconfined, pod-level
 				tweak(p, func(p *corev1.Pod) {
 					p.Spec.SecurityContext.SeccompProfile = seccompProfileUnconfined
 				}),
+				// unset initContainer
 				tweak(p, func(p *corev1.Pod) {
 					p.Spec.SecurityContext.SeccompProfile = nil
 					p.Spec.Containers[0].SecurityContext.SeccompProfile = seccompProfileRuntimeDefault
 				}),
+				// unset container
 				tweak(p, func(p *corev1.Pod) {
 					p.Spec.SecurityContext.SeccompProfile = nil
 					p.Spec.InitContainers[0].SecurityContext.SeccompProfile = seccompProfileRuntimeDefault
 				}),
+				// unconfined, container-level
 				tweak(p, func(p *corev1.Pod) {
 					p.Spec.SecurityContext.SeccompProfile = nil
 					p.Spec.Containers[0].SecurityContext.SeccompProfile = seccompProfileRuntimeDefault
 					p.Spec.InitContainers[0].SecurityContext.SeccompProfile = seccompProfileUnconfined
 				}),
-				tweak(p, func(p *corev1.Pod) {
-					p.Spec.SecurityContext.SeccompProfile = nil
-					p.Spec.Containers[0].SecurityContext.SeccompProfile = seccompProfileUnconfined
-					p.Spec.InitContainers[0].SecurityContext.SeccompProfile = seccompProfileRuntimeDefault
-				}),
 			}
 		},
 	}
 
 	registerFixtureGenerator(
-		fixtureKey{level: api.LevelRestricted, version: api.MajorMinorVersion(1, 19), check: "seccomp_restricted"},
+		fixtureKey{level: api.LevelRestricted, version: api.MajorMinorVersion(1, 19), check: "seccompProfile_restricted"},
 		fixtureData_restricted_1_19,
 	)
 }