Merge pull request #12 from dcarley/dcarley/handle-empty-secrets

[fixes #11] Improve handling of empty secrets

pkg/cmd/modify_secret.go

@@ -27,7 +27,7 @@ type ModifySecretOptions struct {
 	IOStreams   genericclioptions.IOStreams
 
 	args         []string
-	kubeclient   *kubernetes.Clientset
+	kubeclient   kubernetes.Interface
 	secretName   string
 	namespace    string
 	printVersion bool
@@ -128,7 +128,7 @@ func (o *ModifySecretOptions) Run() error {
 	}
 	defer os.Remove(tempfile.Name())
 
-	yamlData, err := yaml.Marshal(data)
+	yamlData, err := yamlOrEmpty(data)
 	if err != nil {
 		return err
 	}
@@ -180,6 +180,16 @@ func (o *ModifySecretOptions) Run() error {
 	return nil
 }
 
+// yamlOrEmpty renders a map to a YAML, with the exception that an empty map
+// becomes an empty byte slice instead of []byte(`{}`)
+func yamlOrEmpty(data map[string]string) ([]byte, error) {
+	if len(data) == 0 {
+		return []byte{}, nil
+	}
+
+	return yaml.Marshal(data)
+}
+
 // getNamespace takes a set of kubectl flag values and returns the namespace we should be operating in
 func getNamespace(flags *genericclioptions.ConfigFlags) string {
 	namespace, _, err := flags.ToRawKubeConfigLoader().Namespace()

pkg/cmd/modify_secret_test.go

@@ -0,0 +1,112 @@
+package cmd
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/kubernetes/fake"
+)
+
+func TestModifySecrets(t *testing.T) {
+	const (
+		name      = "mysecret"
+		namespace = "mynamespace"
+	)
+
+	logrus.SetOutput(ioutil.Discard)
+	origEditor := os.Getenv("EDITOR")
+	if origEditor != "" {
+		defer os.Setenv("EDITOR", origEditor)
+	} else {
+		defer os.Unsetenv("EDITOR")
+	}
+
+	testcases := []struct {
+		name     string
+		command  string
+		secret   map[string][]byte
+		expected map[string][]byte
+	}{
+		{
+			name:     "no changes to empty secret",
+			command:  "touch",
+			secret:   map[string][]byte{},
+			expected: map[string][]byte{},
+		}, {
+			name:     "no changes to populated secret",
+			command:  "touch",
+			secret:   map[string][]byte{"key": []byte("value")},
+			expected: map[string][]byte{"key": []byte("value")},
+		}, {
+			name:     "changes to populated secret",
+			command:  "sed -i= s/value/updated/",
+			secret:   map[string][]byte{"key": []byte("value")},
+			expected: map[string][]byte{"key": []byte("updated")},
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.name, func(t *testing.T) {
+			os.Setenv("EDITOR", tc.command)
+
+			client := fake.NewSimpleClientset(&v1.Secret{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:        name,
+					Namespace:   namespace,
+					Annotations: map[string]string{},
+				},
+				Data: tc.secret,
+			})
+
+			modify := ModifySecretOptions{
+				kubeclient: client,
+				secretName: name,
+				namespace:  namespace,
+			}
+			require.NoError(t, modify.Run())
+
+			object, err := client.Tracker().Get(
+				schema.GroupVersionResource{
+					Version:  "v1",
+					Resource: "secrets",
+				},
+				namespace, name,
+			)
+			require.NoError(t, err)
+			assert.Equal(t, tc.expected, object.(*v1.Secret).Data)
+		})
+	}
+}
+
+func TestYamlOrEmpty(t *testing.T) {
+	testcases := []struct {
+		name     string
+		input    map[string]string
+		expected []byte
+	}{
+		{
+			name:     "empty map",
+			input:    map[string]string{},
+			expected: []byte{},
+		}, {
+			name:     "populated map",
+			input:    map[string]string{"foo": "bar"},
+			expected: []byte("foo: bar\n"),
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.name, func(t *testing.T) {
+			output, err := yamlOrEmpty(tc.input)
+			assert.NoError(t, err)
+			assert.Equal(t, tc.expected, output)
+		})
+	}
+}

pkg/secrets/secrets.go

@@ -7,11 +7,11 @@ import (
 )
 
 // Get gets the secret from Kubernetes
-func Get(kubeclient *kubernetes.Clientset, name, namespace string) (*v1.Secret, error) {
+func Get(kubeclient kubernetes.Interface, name, namespace string) (*v1.Secret, error) {
 	return kubeclient.CoreV1().Secrets(namespace).Get(name, metav1.GetOptions{})
 }
 
 // Update updates the secret to Kubernetes
-func Update(kubeclient *kubernetes.Clientset, secret *v1.Secret) (*v1.Secret, error) {
+func Update(kubeclient kubernetes.Interface, secret *v1.Secret) (*v1.Secret, error) {
 	return kubeclient.CoreV1().Secrets(secret.Namespace).Update(secret)
 }