nit: remove double validation on folder when register flag

cmd/kepler/main.go

@@ -105,6 +105,12 @@ func parseArgsAndConfig() (*config.Config, error) {
 		return nil, err
 	}
 
+	// Validate config before run
+	if err := cfg.Validate(); err != nil {
+		logger.Error("Error validate command line flags", "error", err.Error())
+		return nil, err
+	}
+
 	return cfg, nil
 }
 

config/config.go

@@ -186,10 +186,6 @@ func Load(r io.Reader) (*Config, error) {
 	}
 	cfg.sanitize()
 
-	if err := cfg.Validate(); err != nil {
-		return nil, err
-	}
-
 	return cfg, nil
 }
 
@@ -237,8 +233,8 @@ func RegisterFlags(app *kingpin.Application) ConfigUpdaterFn {
 	logLevel := app.Flag(LogLevelFlag, "Logging level: debug, info, warn, error").Default("info").Enum("debug", "info", "warn", "error")
 	logFormat := app.Flag(LogFormatFlag, "Logging format: text or json").Default("text").Enum("text", "json")
 	// host
-	hostSysFS := app.Flag(HostSysFSFlag, "Host sysfs path").Default("/sys").ExistingDir()
-	hostProcFS := app.Flag(HostProcFSFlag, "Host procfs path").Default("/proc").ExistingDir()
+	hostSysFS := app.Flag(HostSysFSFlag, "Host sysfs path").Default("/sys").String()
+	hostProcFS := app.Flag(HostProcFSFlag, "Host procfs path").Default("/proc").String()
 
 	// monitor
 	monitorInterval := app.Flag(MonitorIntervalFlag,
@@ -308,7 +304,7 @@ func RegisterFlags(app *kingpin.Application) ConfigUpdaterFn {
 		}
 
 		cfg.sanitize()
-		return cfg.Validate()
+		return nil
 	}
 }
 

config/config_test.go

@@ -67,9 +67,9 @@
 `
 	reader := strings.NewReader(yamlData)
 	cfg, err := Load(reader)
-	assert.Error(t, err)
+	assert.NoError(t, err)
+	err = cfg.Validate()
 	assert.Contains(t, err.Error(), "invalid configuration")
-	assert.Nil(t, cfg)
 }
 
 func TestCommandLinePrecedence(t *testing.T) {
@@ -359,7 +359,8 @@
 			_, parseErr := app.Parse(tc.args)
 			assert.Error(t, parseErr, "expected test args to produce a parse error")
 			cfg := DefaultConfig()
-			err := updateConfig(cfg)
+			updateConfig(cfg)
+			err := cfg.Validate()
 			assert.Error(t, err, "invalid input should be rejected by validation")
 			assert.Contains(t, err.Error(), tc.expectedError)
 		})