Update go ucfg (#7510)

* Update go-ucfg to 0.6.0

* Update NewConfigFrom

- update NewConfigFrom to treat raw string input as YAML contents
- Introduce MustNewConfigFrom, which throws a panic on error

NOTICE.txt

@@ -447,8 +447,8 @@ Apache License 2.0
 
 --------------------------------------------------------------------
 Dependency: github.com/elastic/go-ucfg
-Version: v0.5.1
-Revision: 0ba28e36add27704e6b49a7ed8557989a8f4a635
+Version: v0.6.0
+Revision: 9c66f5c432b1d25bdb449a1e588d58b5d0cd7268
 License type (autodetected): Apache-2.0
 ./vendor/github.com/elastic/go-ucfg/LICENSE:
 --------------------------------------------------------------------

libbeat/autodiscover/providers/jolokia/config.go

@@ -33,7 +33,7 @@ var (
 // Config for Jolokia Discovery autodiscover provider
 type Config struct {
 	// List of network interfaces to use for discovery probes
-	Interfaces []InterfaceConfig `config:"interfaces" validate:"nonzero"`
+	Interfaces []InterfaceConfig `config:"interfaces,replace" validate:"nonzero"`
 
 	Builders  []*common.Config        `config:"builders"`
 	Appenders []*common.Config        `config:"appenders"`

libbeat/common/config.go

@@ -87,11 +87,38 @@ func NewConfig() *Config {
 	return fromConfig(ucfg.New())
 }
 
+// NewConfigFrom creates a new Config object from the given input.
+// From can be any kind of structured data (struct, map, array, slice).
+//
+// If from is a string, the contents is treated like raw YAML input. The string
+// will be parsed and a structure config object is build from the parsed
+// result.
 func NewConfigFrom(from interface{}) (*Config, error) {
+	if str, ok := from.(string); ok {
+		c, err := yaml.NewConfig([]byte(str), configOpts...)
+		return fromConfig(c), err
+	}
+
 	c, err := ucfg.NewFrom(from, configOpts...)
 	return fromConfig(c), err
 }
 
+// MustNewConfigFrom creates a new Config object from the given input.
+// From can be any kind of structured data (struct, map, array, slice).
+//
+// If from is a string, the contents is treated like raw YAML input. The string
+// will be parsed and a structure config object is build from the parsed
+// result.
+//
+// MustNewConfigFrom panics if an error occurs.
+func MustNewConfigFrom(from interface{}) *Config {
+	cfg, err := NewConfigFrom(from)
+	if err != nil {
+		panic(err)
+	}
+	return cfg
+}
+
 func MergeConfigs(cfgs ...*Config) (*Config, error) {
 	config := NewConfig()
 	for _, c := range cfgs {