Fix default scope in add_nomad_metadata (elastic#24559)

Fix default scope in add_nomad_metadata. It is set to local, but
it should be node. Fix also error message that showed that local
is a valid value.

CHANGELOG.next.asciidoc

@@ -399,6 +399,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fix Netflow module issue with missing `internal_networks` config parameter. {issue}24094[24094] {pull}24110[24110]
 - in httpjson input using encode_as "application/x-www-form-urlencoded" now sets Content-Type correctly {issue}24331[24331] {pull}24336[24336]
 - Fix netflow module ignoring detect_sequence_reset flag. {issue}24268[24268] {pull}24270[24270]
+- Fix default `scope` in `add_nomad_metadata`. {issue}24559[24559]
 
 *Heartbeat*
 

x-pack/libbeat/autodiscover/providers/nomad/config.go

@@ -64,7 +64,7 @@ func (c *Config) Validate() error {
 	case ScopeNode:
 	case ScopeCluster:
 	default:
-		return fmt.Errorf("invalid value for `scope`, select `%s` or `%s`", ScopeNode, ScopeCluster)
+		return fmt.Errorf("invalid value for `scope`: %s, select `%s` or `%s`", c.Scope, ScopeNode, ScopeCluster)
 	}
 	return nil
 }

x-pack/libbeat/processors/add_nomad_metadata/config.go

@@ -40,7 +40,7 @@ func (c *nomadAnnotatorConfig) Validate() error {
 	case ScopeNode:
 	case ScopeCluster:
 	default:
-		return fmt.Errorf("invalid value for `scope`, select `local` or `global`")
+		return fmt.Errorf("invalid value for `scope`: %s, select `%s` or `%s`", c.Scope, ScopeNode, ScopeCluster)
 	}
 	return nil
 }
@@ -57,7 +57,7 @@ func defaultNomadAnnotatorConfig() nomadAnnotatorConfig {
 		Region:          "",
 		Namespace:       "",
 		SecretID:        "",
-		Scope:           "local",
+		Scope:           ScopeNode,
 		syncPeriod:      5 * time.Second,
 		CleanupTimeout:  60 * time.Second,
 		DefaultMatchers: Enabled{true},