add methods to allow selection and exclusion of resources by gvk (#581)

go/fn/examples/const.go

@@ -14,6 +14,14 @@
 
 package example
 
+import "github.com/GoogleContainerTools/kpt-functions-sdk/go/fn"
+
 const (
-	appsv1 = "apps/v1"
+	apps = "apps"
+	v1   = "v1"
 )
+
+func hasDesiredGVK(obj *fn.KubeObject) bool {
+	return obj.IsGVK(apps, v1, "Deployment") || obj.IsGVK(apps, v1, "StatefulSet") ||
+		obj.IsGVK(apps, v1, "DaemonSet") || obj.IsGVK(apps, v1, "ReplicaSet")
+}

go/fn/examples/example_filter_GVK_test.go

@@ -35,10 +35,8 @@ func updateReplicas(rl *fn.ResourceList) (bool, error) {
 	}
 	var replicas int
 	rl.FunctionConfig.GetOrDie(&replicas, "replicas")
-	for i, obj := range rl.Items {
-		if obj.IsGVK("apps/v1", "Deployment") {
-			rl.Items[i].SetOrDie(replicas, "spec", "replicas")
-		}
+	for i := range rl.Items.Where(fn.IsGVK("apps", "v1", "Deployment")) {
+		rl.Items[i].SetOrDie(replicas, "spec", "replicas")
 	}
 	return true, nil
 }

go/fn/examples/example_logger_injector_test.go

@@ -39,28 +39,26 @@ func injectLogger(rl *fn.ResourceList) (bool, error) {
 	if err := rl.FunctionConfig.As(&li); err != nil {
 		return false, err
 	}
-	for i, obj := range rl.Items {
-		if obj.IsGVK(appsv1, "Deployment") || obj.IsGVK(appsv1, "StatefulSet") ||
-			obj.IsGVK(appsv1, "DaemonSet") || obj.IsGVK(appsv1, "ReplicaSet") {
-			var containers []corev1.Container
-			obj.GetOrDie(&containers, "spec", "template", "spec", "containers")
-			foundTargetContainer := false
-			for j, container := range containers {
-				if container.Name == li.ContainerName {
-					containers[j].Image = li.ImageName
-					foundTargetContainer = true
-					break
-				}
+	for i, obj := range rl.Items.Where(hasDesiredGVK) {
+		var containers []corev1.Container
+		obj.GetOrDie(&containers, "spec", "template", "spec", "containers")
+		foundTargetContainer := false
+		for j, container := range containers {
+			if container.Name == li.ContainerName {
+				containers[j].Image = li.ImageName
+				foundTargetContainer = true
+				break
 			}
-			if !foundTargetContainer {
-				c := corev1.Container{
-					Name:  li.ContainerName,
-					Image: li.ImageName,
-				}
-				containers = append(containers, c)
+		}
+		if !foundTargetContainer {
+			c := corev1.Container{
+				Name:  li.ContainerName,
+				Image: li.ImageName,
 			}
-			rl.Items[i].SetOrDie(containers, "spec", "template", "spec", "containers")
+			containers = append(containers, c)
 		}
+		rl.Items[i].SetOrDie(containers, "spec", "template", "spec", "containers")
+
 	}
 	return true, nil
 }

go/fn/examples/example_read_field_test.go

@@ -29,26 +29,24 @@ func Example_aReadField() {
 }
 
 func readField(rl *fn.ResourceList) (bool, error) {
-	for _, obj := range rl.Items {
-		if obj.IsGVK("apps/v1", "Deployment") {
-			// Style 1: like using unstrucuted.Unstructured, get/set the value from field paths*
-			replicas := obj.NestedInt64OrDie("spec", "replicas")
-			fn.Logf("replicas is %v\n", replicas)
-			paused := obj.NestedBoolOrDie("spec", "paused")
-			fn.Logf("paused is %v\n", paused)
-			// Update strategy from Recreate to RollingUpdate.
-			if strategy := obj.NestedStringOrDie("spec", "strategy", "type"); strategy == "Recreate" {
-				obj.SetNestedStringOrDie("RollingUpdate", "spec", "strategy", "type")
-			}
+	for _, obj := range rl.Items.Where(fn.IsGVK("apps", "v1", "Deployment")) {
+		// Style 1: like using unstrucuted.Unstructured, get/set the value from field paths*
+		replicas := obj.NestedInt64OrDie("spec", "replicas")
+		fn.Logf("replicas is %v\n", replicas)
+		paused := obj.NestedBoolOrDie("spec", "paused")
+		fn.Logf("paused is %v\n", paused)
+		// Update strategy from Recreate to RollingUpdate.
+		if strategy := obj.NestedStringOrDie("spec", "strategy", "type"); strategy == "Recreate" {
+			obj.SetNestedStringOrDie("RollingUpdate", "spec", "strategy", "type")
+		}
 
-			// Style 2: operate each resource layer via `GetMap`
-			spec := obj.GetMap("spec")
-			replicas = spec.GetInt("replicas")
-			fn.Logf("replicas is %v\n", replicas)
-			nodeSelector := spec.GetMap("template").GetMap("spec").GetMap("nodeSelector")
-			if nodeSelector.GetString("disktype") != "ssd" {
-				nodeSelector.SetNestedStringOrDie("ssd", "disktype")
-			}
+		// Style 2: operate each resource layer via `GetMap`
+		spec := obj.GetMap("spec")
+		replicas = spec.GetInt("replicas")
+		fn.Logf("replicas is %v\n", replicas)
+		nodeSelector := spec.GetMap("template").GetMap("spec").GetMap("nodeSelector")
+		if nodeSelector.GetString("disktype") != "ssd" {
+			nodeSelector.SetNestedStringOrDie("ssd", "disktype")
 		}
 	}
 	return true, nil

go/fn/examples/example_select_exclude_test.go

@@ -0,0 +1,23 @@
+package example
+
+import (
+	"os"
+
+	"github.com/GoogleContainerTools/kpt-functions-sdk/go/fn"
+)
+
+// This example implements a function that selectively includes or excludes some resources.
+
+func Example_selectExclude() {
+	if err := fn.AsMain(fn.ResourceListProcessorFunc(selectResources)); err != nil {
+		os.Exit(1)
+	}
+}
+
+// selectResources keeps all resources with the GVK apps/v1 Deployment that do
+// NOT have the label foo=bar, and removes the rest.
+func selectResources(rl *fn.ResourceList) (bool, error) {
+	rl.Items = rl.Items.Where(fn.IsGVK("apps", "v1", "Deployment")).
+		WhereNot(fn.HasLabels(map[string]string{"foo": "bar"}))
+	return true, nil
+}

go/fn/examples/example_validator_test.go

@@ -30,14 +30,11 @@ func Example_validator() {
 
 func validator(rl *fn.ResourceList) (bool, error) {
 	var results fn.Results
-	for _, obj := range rl.Items {
-		if obj.IsGVK(appsv1, "Deployment") || obj.IsGVK(appsv1, "StatefulSet") ||
-			obj.IsGVK(appsv1, "DaemonSet") || obj.IsGVK(appsv1, "ReplicaSet") {
-			var runAsNonRoot bool
-			obj.GetOrDie(&runAsNonRoot, "spec", "template", "spec", "securityContext", "runAsNonRoot")
-			if !runAsNonRoot {
-				results = append(results, fn.ConfigObjectResult("`spec.template.spec.securityContext.runAsNonRoot` must be set to true", obj, fn.Error))
-			}
+	for _, obj := range rl.Items.Where(hasDesiredGVK) {
+		var runAsNonRoot bool
+		obj.GetOrDie(&runAsNonRoot, "spec", "template", "spec", "securityContext", "runAsNonRoot")
+		if !runAsNonRoot {
+			results = append(results, fn.ConfigObjectResult("`spec.template.spec.securityContext.runAsNonRoot` must be set to true", obj, fn.Error))
 		}
 	}
 	return true, results

go/fn/examples/go.mod

@@ -8,36 +8,41 @@ require (
 	github.com/GoogleContainerTools/kpt-functions-sdk/go/fn v0.0.0
 	k8s.io/api v0.24.0
 	k8s.io/apimachinery v0.24.0
-	sigs.k8s.io/kustomize/kyaml v0.13.6
+	sigs.k8s.io/kustomize/kyaml v0.13.7-0.20220418212550-9d5491c2e20c
 )
 
 require (
 	github.com/PuerkitoBio/purell v1.1.1 // indirect
 	github.com/PuerkitoBio/urlesc v0.0.0-20170810143723-de5bf2ad4578 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/go-errors/errors v1.0.1 // indirect
+	github.com/go-errors/errors v1.4.2 // indirect
 	github.com/go-logr/logr v1.2.0 // indirect
 	github.com/go-openapi/jsonpointer v0.19.5 // indirect
-	github.com/go-openapi/jsonreference v0.19.3 // indirect
-	github.com/go-openapi/swag v0.19.5 // indirect
+	github.com/go-openapi/jsonreference v0.19.6 // indirect
+	github.com/go-openapi/swag v0.21.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/gnostic v0.5.7-v3refs // indirect
 	github.com/google/gofuzz v1.1.0 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/mailru/easyjson v0.7.0 // indirect
+	github.com/kr/pretty v0.2.1 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/monochromegane/go-gitignore v0.0.0-20200626010858-205db1a8cc00 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/testify v1.7.0 // indirect
-	github.com/xlab/treeprint v0.0.0-20181112141820-a009c3971eca // indirect
-	golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd // indirect
+	github.com/stretchr/testify v1.7.1 // indirect
+	github.com/xlab/treeprint v1.1.0 // indirect
+	golang.org/x/net v0.0.0-20220412020605-290c469a71a5 // indirect
 	golang.org/x/text v0.3.7 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 	k8s.io/klog/v2 v2.60.1 // indirect
-	k8s.io/kube-openapi v0.0.0-20220328201542-3ee0da9b0b42 // indirect
+	k8s.io/kube-openapi v0.0.0-20220401212409-b28bf2818661 // indirect
 	k8s.io/utils v0.0.0-20220210201930-3a6ce19ff2f9 // indirect
 	sigs.k8s.io/json v0.0.0-20211208200746-9f7c6b3444d2 // indirect
 	sigs.k8s.io/structured-merge-diff/v4 v4.2.1 // indirect