+ app, config: add symlink support, allow to specify absolute path in log_file

app.go

@@ -288,7 +288,11 @@ func configureLogger(args options) {
 		}
 	} else {
 		logFilePath := filepath.Join(config.ourWorkingDir, ls.LogFile)
-		file, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0755)
+		if filepath.IsAbs(ls.LogFile) {
+			logFilePath = ls.LogFile
+		}
+
+		file, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
 		if err != nil {
 			log.Fatalf("cannot create a log file: %s", err)
 		}

config.go

@@ -137,9 +137,15 @@ var config = configuration{
 
 // getConfigFilename returns path to the current config file
 func (c *configuration) getConfigFilename() string {
-	configFile := config.ourConfigFilename
+	configFile, err := filepath.EvalSymlinks(config.ourConfigFilename)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			log.Error("unexpected error while config file path evaluation: %s", err)
+		}
+		configFile = config.ourConfigFilename
+	}
 	if !filepath.IsAbs(configFile) {
-		configFile = filepath.Join(config.ourWorkingDir, config.ourConfigFilename)
+		configFile = filepath.Join(config.ourWorkingDir, configFile)
 	}
 	return configFile
 }