Set DisallowUnknownFields when config is checked

cmds/houndd/main.go

@@ -143,14 +143,14 @@ func main() {
 	}
 
 	var cfg config.Config
-	if err := cfg.LoadFromFile(*flagConf); err != nil {
+	if err := cfg.LoadFromFile(*flagConf, *flagCheckConf); err != nil {
 		panic(err)
 	}
 
-  if *flagCheckConf {
-    return
-  } 
-  
+	if *flagCheckConf {
+		return
+	}
+
 	// Start the web server on a background routine.
 	ws := web.Start(&cfg, *flagAddr, *flagDev)
 

config/config.go

@@ -188,14 +188,19 @@ func mergeVCSConfigs(cfg *Config) error {
 	return nil
 }
 
-func (c *Config) LoadFromFile(filename string) error {
+func (c *Config) LoadFromFile(filename string, disallowUnknownFields bool) error {
 	r, err := os.Open(filename)
 	if err != nil {
 		return err
 	}
 	defer r.Close()
 
-	if err := json.NewDecoder(r).Decode(c); err != nil {
+	decoder := json.NewDecoder(r)
+	if disallowUnknownFields {
+		decoder.DisallowUnknownFields()
+	}
+
+	if decoder.Decode(c); err != nil {
 		return err
 	}
 

config/config_test.go

@@ -20,7 +20,7 @@ func rootDir() string {
 // add examples, we don't muck them up.
 func TestExampleConfigsAreValid(t *testing.T) {
 	var cfg Config
-	if err := cfg.LoadFromFile(filepath.Join(rootDir(), exampleConfigFile)); err != nil {
+	if err := cfg.LoadFromFile(filepath.Join(rootDir(), exampleConfigFile), true); err != nil {
 		t.Fatalf("Unable to parse %s: %s", exampleConfigFile, err)
 	}