kd: workaround for YAML -> JSON template reencoding

Works around the following yaml issue:

    go-yaml/yaml#139

go/src/koding/kites/kloud/stack/kloud.go

@@ -171,7 +171,7 @@ func ReadProviders(template []byte) ([]string, error) {
 		return nil, err
 	}
 
-	providers := make([]string, len(v.Provider))
+	providers := make([]string, 0, len(v.Provider))
 
 	for p := range v.Provider {
 		providers = append(providers, p)

go/src/koding/klientctl/endpoint/stack/export_test.go

@@ -1,3 +1,4 @@
 package stack
 
-func FixHCL(v interface{}) { fixHCL(v) }
+func FixHCL(v interface{})              { fixHCL(v) }
+func FixYAML(v interface{}) interface{} { return fixYAML(v) }

go/src/koding/klientctl/endpoint/stack/stack.go

@@ -15,15 +15,13 @@ import (
 	yaml "gopkg.in/yaml.v2"
 )
 
-// CreateOptions
 type CreateOptions struct {
 	Team        string
 	Title       string
 	Credentials []string
 	Template    []byte
 }
 
-// Valid
 func (opts *CreateOptions) Valid() error {
 	if opts == nil {
 		return errors.New("stack: arguments are missing")
@@ -36,16 +34,13 @@ func (opts *CreateOptions) Valid() error {
 	return nil
 }
 
-// DefaultClient
-var DefaultClient Client
+var DefaultClient = &Client{}
 
-// Client
 type Client struct {
 	Kloud      *kloud.Client
 	Credential *credential.Client
 }
 
-// Create
 func (c *Client) Create(opts *CreateOptions) (*stack.ImportResponse, error) {
 	if err := opts.Valid(); err != nil {
 		return nil, err
@@ -135,7 +130,7 @@ func (c *Client) jsonReencode(data []byte) ([]byte, error) {
 	var ymlv interface{}
 
 	if err := yaml.Unmarshal(data, &ymlv); err == nil {
-		return json.Marshal(ymlv)
+		return json.Marshal(fixYAML(ymlv))
 	}
 
 	var hclv interface{}
@@ -154,6 +149,39 @@ func Create(opts *CreateOptions) (*stack.ImportResponse, error) {
 	return DefaultClient.Create(opts)
 }
 
+// fixYAML is a best-effort of fixing representation of
+// YAML-encoded value, so it can be marshaled to a valid JSON.
+//
+// YAML creates types like map[interface{}]interface{}, which are
+// not a valid JSON types.
+//
+// Related issue:
+//
+//   https://github.com/go-yaml/yaml/issues/139
+//
+func fixYAML(v interface{}) interface{} {
+	switch v := v.(type) {
+	case map[interface{}]interface{}:
+		fixedV := make(map[string]interface{}, len(v))
+
+		for k, v := range v {
+			fixedV[fmt.Sprintf("%v", k)] = fixYAML(v)
+		}
+
+		return fixedV
+	case []interface{}:
+		fixedV := make([]interface{}, len(v))
+
+		for i := range v {
+			fixedV[i] = fixYAML(v[i])
+		}
+
+		return fixedV
+	default:
+		return v
+	}
+}
+
 // fixHCL is a best-effort method to "fix" value representation of
 // HCL-encoded value, so it can be marshaled to a valid JSON.
 //

go/src/koding/klientctl/endpoint/stack/stack_test.go

@@ -102,6 +102,64 @@ func TestFixHCL(t *testing.T) {
 	}
 }
 
+func TestFixYAML(t *testing.T) {
+	cases := map[string]struct {
+		yaml interface{}
+		want interface{}
+	}{
+		"fix map": {
+			map[interface{}]interface{}{
+				"abc": 1,
+			},
+			map[string]interface{}{
+				"abc": 1,
+			},
+		},
+		"fix slice of maps": {
+			[]interface{}{
+				"abc",
+				map[interface{}]interface{}{
+					"abc": 1,
+				},
+				1,
+			},
+			[]interface{}{
+				"abc",
+				map[string]interface{}{
+					"abc": 1,
+				},
+				1,
+			},
+		},
+		"fix nested maps": {
+			map[interface{}]interface{}{
+				"abc": map[interface{}]interface{}{
+					"abc": map[interface{}]interface{}{
+						"abc": 1,
+					},
+				},
+			},
+			map[string]interface{}{
+				"abc": map[string]interface{}{
+					"abc": map[string]interface{}{
+						"abc": 1,
+					},
+				},
+			},
+		},
+	}
+
+	for name, cas := range cases {
+		t.Run(name, func(t *testing.T) {
+			got := stack.FixYAML(cas.yaml)
+
+			if !reflect.DeepEqual(got, cas.want) {
+				t.Fatalf("got %#v, want %#v", got, cas.want)
+			}
+		})
+	}
+}
+
 func mustJSON(v interface{}) []byte {
 	p, err := json.MarshalIndent(v, "", "\t")
 	if err != nil {