Merge pull request #79176 from verb/debug-iterate-containers

Add helpers for iterating containers in a pod

pkg/apis/core/pods/BUILD

@@ -5,13 +5,21 @@ go_library(
     srcs = ["helpers.go"],
     importpath = "k8s.io/kubernetes/pkg/apis/core/pods",
     visibility = ["//visibility:public"],
-    deps = ["//pkg/fieldpath:go_default_library"],
+    deps = [
+        "//pkg/apis/core:go_default_library",
+        "//pkg/fieldpath:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+    ],
 )
 
 go_test(
     name = "go_default_test",
     srcs = ["helpers_test.go"],
     embed = [":go_default_library"],
+    deps = [
+        "//pkg/apis/core:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+    ],
 )
 
 filegroup(

pkg/apis/core/pods/helpers.go

@@ -19,9 +19,27 @@ package pods
 import (
 	"fmt"
 
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/fieldpath"
 )
 
+// ContainerVisitorWithPath is called with each container and the field.Path to that container
+type ContainerVisitorWithPath func(container *api.Container, path *field.Path)
+
+// VisitContainersWithPath invokes the visitor function with a pointer to the spec
+// of every container in the given pod spec and the field.Path to that container.
+func VisitContainersWithPath(podSpec *api.PodSpec, visitor ContainerVisitorWithPath) {
+	path := field.NewPath("spec", "initContainers")
+	for i := range podSpec.InitContainers {
+		visitor(&podSpec.InitContainers[i], path.Index(i))
+	}
+	path = field.NewPath("spec", "containers")
+	for i := range podSpec.Containers {
+		visitor(&podSpec.Containers[i], path.Index(i))
+	}
+}
+
 // ConvertDownwardAPIFieldLabel converts the specified downward API field label
 // and its value in the pod of the specified version to the internal version,
 // and returns the converted label and value. This function returns an error if

pkg/apis/core/pods/helpers_test.go

@@ -17,9 +17,71 @@ limitations under the License.
 package pods
 
 import (
+	"reflect"
 	"testing"
+
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	api "k8s.io/kubernetes/pkg/apis/core"
 )
 
+func TestVisitContainersWithPath(t *testing.T) {
+	testCases := []struct {
+		description string
+		haveSpec    *api.PodSpec
+		wantNames   []string
+	}{
+		{
+			"empty podspec",
+			&api.PodSpec{},
+			[]string{},
+		},
+		{
+			"regular containers",
+			&api.PodSpec{
+				Containers: []api.Container{
+					{Name: "c1"},
+					{Name: "c2"},
+				},
+			},
+			[]string{"spec.containers[0]", "spec.containers[1]"},
+		},
+		{
+			"init containers",
+			&api.PodSpec{
+				InitContainers: []api.Container{
+					{Name: "i1"},
+					{Name: "i2"},
+				},
+			},
+			[]string{"spec.initContainers[0]", "spec.initContainers[1]"},
+		},
+		{
+			"regular and init containers",
+			&api.PodSpec{
+				Containers: []api.Container{
+					{Name: "c1"},
+					{Name: "c2"},
+				},
+				InitContainers: []api.Container{
+					{Name: "i1"},
+					{Name: "i2"},
+				},
+			},
+			[]string{"spec.initContainers[0]", "spec.initContainers[1]", "spec.containers[0]", "spec.containers[1]"},
+		},
+	}
+
+	for _, tc := range testCases {
+		gotNames := []string{}
+		VisitContainersWithPath(tc.haveSpec, func(c *api.Container, p *field.Path) {
+			gotNames = append(gotNames, p.String())
+		})
+		if !reflect.DeepEqual(gotNames, tc.wantNames) {
+			t.Errorf("VisitContainersWithPath() for test case %q visited containers %q, wanted to visit %q", tc.description, gotNames, tc.wantNames)
+		}
+	}
+}
+
 func TestConvertDownwardAPIFieldLabel(t *testing.T) {
 	testCases := []struct {
 		version       string

pkg/apis/core/validation/validation.go

@@ -3434,17 +3434,13 @@ func ValidateAppArmorPodAnnotations(annotations map[string]string, spec *core.Po
 }
 
 func podSpecHasContainer(spec *core.PodSpec, containerName string) bool {
-	for _, c := range spec.InitContainers {
+	var hasContainer bool
+	podshelper.VisitContainersWithPath(spec, func(c *core.Container, _ *field.Path) {
 		if c.Name == containerName {
-			return true
+			hasContainer = true
 		}
-	}
-	for _, c := range spec.Containers {
-		if c.Name == containerName {
-			return true
-		}
-	}
-	return false
+	})
+	return hasContainer
 }
 
 const (