feat: implement deprecation warnings in helm lint (#7986)

* feat: implement deprecation warnings in helm lint

Signed-off-by: Matt Butcher <matt.butcher@microsoft.com>

* added more deprecated APIs

Signed-off-by: Matt Butcher <matt.butcher@microsoft.com>

pkg/chartutil/save.go

@@ -34,6 +34,9 @@ import (
 var headerBytes = []byte("+aHR0cHM6Ly95b3V0dS5iZS96OVV6MWljandyTQo=")
 
 // SaveDir saves a chart as files in a directory.
+//
+// This takes the chart name, and creates a new subdirectory inside of the given dest
+// directory, writing the chart's contents to that subdirectory.
 func SaveDir(c *chart.Chart, dest string) error {
 	// Create the chart directory
 	outdir := filepath.Join(dest, c.Name())

pkg/lint/rules/deprecations.go

@@ -0,0 +1,64 @@
+/*
+Copyright The Helm 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 rules // import "helm.sh/helm/v3/pkg/lint/rules"
+
+import "fmt"
+
+// deprecatedAPIs lists APIs that are deprecated (left) with suggested alternatives (right).
+//
+// An empty rvalue indicates that the API is completely deprecated.
+var deprecatedAPIs = map[string]string{
+	"extensions/v1 Deployment":             "apps/v1 Deployment",
+	"extensions/v1 DaemonSet":              "apps/v1 DaemonSet",
+	"extensions/v1 ReplicaSet":             "apps/v1 ReplicaSet",
+	"extensions/v1beta1 PodSecurityPolicy": "policy/v1beta1 PodSecurityPolicy",
+	"extensions/v1beta1 NetworkPolicy":     "networking.k8s.io/v1beta1 NetworkPolicy",
+	"extensions/v1beta1 Ingress":           "networking.k8s.io/v1beta1 Ingress",
+	"apps/v1beta1 Deployment":              "apps/v1 Deployment",
+	"apps/v1beta1 StatefulSet":             "apps/v1 StatefulSet",
+	"apps/v1beta1 DaemonSet":               "apps/v1 DaemonSet",
+	"apps/v1beta1 ReplicaSet":              "apps/v1 ReplicaSet",
+	"apps/v1beta2 Deployment":              "apps/v1 Deployment",
+	"apps/v1beta2 StatefulSet":             "apps/v1 StatefulSet",
+	"apps/v1beta2 DaemonSet":               "apps/v1 DaemonSet",
+	"apps/v1beta2 ReplicaSet":              "apps/v1 ReplicaSet",
+}
+
+// deprecatedAPIError indicates than an API is deprecated in Kubernetes
+type deprecatedAPIError struct {
+	Deprecated  string
+	Alternative string
+}
+
+func (e deprecatedAPIError) Error() string {
+	msg := fmt.Sprintf("the kind %q is deprecated", e.Deprecated)
+	if e.Alternative != "" {
+		msg += fmt.Sprintf(" in favor of %q", e.Alternative)
+	}
+	return msg
+}
+
+func validateNoDeprecations(resource *K8sYamlStruct) error {
+	gvk := fmt.Sprintf("%s %s", resource.APIVersion, resource.Kind)
+	if alt, ok := deprecatedAPIs[gvk]; ok {
+		return deprecatedAPIError{
+			Deprecated:  gvk,
+			Alternative: alt,
+		}
+	}
+	return nil
+}

pkg/lint/rules/deprecations_test.go

@@ -0,0 +1,42 @@
+/*
+Copyright The Helm 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 rules // import "helm.sh/helm/v3/pkg/lint/rules"
+
+import "testing"
+
+func TestValidateNoDeprecations(t *testing.T) {
+	deprecated := &K8sYamlStruct{
+		APIVersion: "extensions/v1",
+		Kind:       "Deployment",
+	}
+	err := validateNoDeprecations(deprecated)
+	if err == nil {
+		t.Fatal("Expected deprecated extension to be flagged")
+	}
+
+	depErr := err.(deprecatedAPIError)
+	if depErr.Alternative != "apps/v1 Deployment" {
+		t.Errorf("Expected %q to be replaced by %q", depErr.Deprecated, depErr.Alternative)
+	}
+
+	if err := validateNoDeprecations(&K8sYamlStruct{
+		APIVersion: "v1",
+		Kind:       "Pod",
+	}); err != nil {
+		t.Errorf("Expected a v1 Pod to not be deprecated")
+	}
+}

pkg/lint/rules/template.go

@@ -131,6 +131,7 @@ func Templates(linter *support.Linter, values map[string]interface{}, namespace
 			// on this linter run.
 			linter.RunLinterRule(support.ErrorSev, path, validateYamlContent(err))
 			linter.RunLinterRule(support.ErrorSev, path, validateMetadataName(&yamlStruct))
+			linter.RunLinterRule(support.ErrorSev, path, validateNoDeprecations(&yamlStruct))
 		}
 	}
 }
@@ -190,7 +191,9 @@ func validateNoReleaseTime(manifest []byte) error {
 // DEPRECATED: In Helm 4, this will be made a private type, as it is for use only within
 // the rules package.
 type K8sYamlStruct struct {
-	Metadata k8sYamlMetadata
+	APIVersion string `json:"apiVersion"`
+	Kind       string
+	Metadata   k8sYamlMetadata
 }
 
 type k8sYamlMetadata struct {

pkg/lint/rules/template_test.go

@@ -22,6 +22,9 @@ import (
 	"strings"
 	"testing"
 
+	"helm.sh/helm/v3/internal/test/ensure"
+	"helm.sh/helm/v3/pkg/chart"
+	"helm.sh/helm/v3/pkg/chartutil"
 	"helm.sh/helm/v3/pkg/lint/support"
 )
 
@@ -130,3 +133,44 @@ func TestValidateMetadataName(t *testing.T) {
 		}
 	}
 }
+
+func TestDeprecatedAPIFails(t *testing.T) {
+	mychart := chart.Chart{
+		Metadata: &chart.Metadata{
+			APIVersion: "v2",
+			Name:       "failapi",
+			Version:    "0.1.0",
+			Icon:       "satisfy-the-linting-gods.gif",
+		},
+		Templates: []*chart.File{
+			{
+				Name: "templates/baddeployment.yaml",
+				Data: []byte("apiVersion: apps/v1beta1\nkind: Deployment\nmetadata:\n  name: baddep"),
+			},
+			{
+				Name: "templates/goodsecret.yaml",
+				Data: []byte("apiVersion: v1\nkind: Secret\nmetadata:\n  name: goodsecret"),
+			},
+		},
+	}
+	tmpdir := ensure.TempDir(t)
+	defer os.RemoveAll(tmpdir)
+
+	if err := chartutil.SaveDir(&mychart, tmpdir); err != nil {
+		t.Fatal(err)
+	}
+
+	linter := support.Linter{ChartDir: filepath.Join(tmpdir, mychart.Name())}
+	Templates(&linter, values, namespace, strict)
+	if l := len(linter.Messages); l != 1 {
+		for i, msg := range linter.Messages {
+			t.Logf("Message %d: %s", i, msg)
+		}
+		t.Fatalf("Expected 1 lint error, got %d", l)
+	}
+
+	err := linter.Messages[0].Err.(deprecatedAPIError)
+	if err.Deprecated != "apps/v1beta1 Deployment" {
+		t.Errorf("Surprised to learn that %q is deprecated", err.Deprecated)
+	}
+}