service: fix darwin bug. Move KV code to central location.

service.go

@@ -29,7 +29,53 @@ type Config struct {
 	UserService      bool // Install as a current user service.
 
 	// System specific parameters.
-	KV map[string]interface{}
+	KV KeyValue
+}
+
+type KeyValue map[string]interface{}
+
+// Bool returns the value of the given name, assuming the value is a boolean.
+// If the value isn't found or is not of the type, the defaultValue is returned.
+func (kv KeyValue) bool(name string, defaultValue bool) bool {
+	if v, found := kv[name]; found {
+		if castValue, is := v.(bool); is {
+			return castValue
+		}
+	}
+	return defaultValue
+}
+
+// Int returns the value of the given name, assuming the value is an int.
+// If the value isn't found or is not of the type, the defaultValue is returned.
+func (kv KeyValue) int(name string, defaultValue int) int {
+	if v, found := kv[name]; found {
+		if castValue, is := v.(int); is {
+			return castValue
+		}
+	}
+	return defaultValue
+}
+
+// Int returns the value of the given name, assuming the value is a string.
+// If the value isn't found or is not of the type, the defaultValue is returned.
+func (kv KeyValue) string(name string, defaultValue string) string {
+	if v, found := kv[name]; found {
+		if castValue, is := v.(string); is {
+			return castValue
+		}
+	}
+	return defaultValue
+}
+
+// Int returns the value of the given name, assuming the value is a float64.
+// If the value isn't found or is not of the type, the defaultValue is returned.
+func (kv KeyValue) float64(name string, defaultValue float64) float64 {
+	if v, found := kv[name]; found {
+		if castValue, is := v.(float64); is {
+			return castValue
+		}
+	}
+	return defaultValue
 }
 
 // Alpha API. Do not yet use.

service_darwin.go

@@ -43,15 +43,6 @@ func (s *darwinLaunchdService) getServiceFilePath() (string, error) {
 	return "/Library/LaunchDaemons/" + s.Name + ".plist", nil
 }
 
-func (s *darwinLaunchdService) kvBool(name string, def bool) bool {
-	if v, found := s.KV["KeepAlive"]; found {
-		if castValue, is := v.(bool); is {
-			return castValue
-		}
-	}
-	return def
-}
-
 func (s *darwinLaunchdService) Install() error {
 	confPath, err := s.getServiceFilePath()
 	if err != nil {
@@ -81,8 +72,8 @@ func (s *darwinLaunchdService) Install() error {
 	}{
 		Config:    s.Config,
 		Path:      path,
-		KeepAlive: s.kvBool("KeepAlive", true),
+		KeepAlive: s.KV.bool("KeepAlive", true),
-		RunAtLoad: s.kvBool("RunAtLoad", false),
+		RunAtLoad: s.KV.bool("RunAtLoad", false),
 	}
 
 	functions := template.FuncMap{