Merge pull request #1 from rrreeeyyy/fix-error-log-output

Use (os.Stdout, os.Stderr) as default instead of (/dev/stdout, /dev/stderr)

Author: rrreeeyyy

.gitignore

@@ -1 +1,3 @@
 /bin
+access.log
+error.log

cli/main.go

@@ -48,26 +48,38 @@ func openWritableFile(path string) (*os.File, error) {
 }
 
 func start(config *config.Config) {
-	ef, err := openWritableFile(*config.ErrorLogConfig.Path)
-	if err != nil {
-		log.Fatal(err)
+	var err error
+	var errorLogger *log.Logger
+	if config.ErrorLogConfig != nil {
+		ef, err := openWritableFile(*config.ErrorLogConfig.Path)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer ef.Close()
+		errorLogger = log.New(ef, "", log.LstdFlags)
+	} else {
+		errorLogger = log.New(os.Stderr, "", log.LstdFlags)
 	}
-	defer ef.Close()
 
-	errorLogger := log.New(ef, "", log.LstdFlags)
 	errorLogger.Printf("INFO: ExporterProxy v%s", Version)
 
 	var accessLogger accesslogger.AccessLogger
 	if config.AccessLogConfig != nil {
-		af, err := openWritableFile(*config.AccessLogConfig.Path)
-		if err != nil {
-			errorLogger.Fatal(err)
-		}
-		defer af.Close()
-
-		accessLogger, err = accesslogger.New(*config.AccessLogConfig.Format, af, config.AccessLogConfig.Fields)
-		if err != nil {
-			errorLogger.Fatal(err)
+		if config.AccessLogConfig.Path != nil {
+			af, err := openWritableFile(*config.AccessLogConfig.Path)
+			if err != nil {
+				errorLogger.Fatal(err)
+			}
+			defer af.Close()
+			accessLogger, err = accesslogger.New(*config.AccessLogConfig.Format, af, config.AccessLogConfig.Fields)
+			if err != nil {
+				errorLogger.Fatal(err)
+			}
+		} else {
+			accessLogger, err = accesslogger.New(*config.AccessLogConfig.Format, os.Stdout, config.AccessLogConfig.Fields)
+			if err != nil {
+				errorLogger.Fatal(err)
+			}
 		}
 	}
 

config.example.yml

@@ -4,17 +4,17 @@
 #   127.0.0.1:8080
 #   SERVER_STARTER:0.0.0.0:8080
 #   SERVER_STARTER:/path/to/socket
-listen: "SERVER_STARTER:0.0.0.0:9099"
+listen: "0.0.0.0:9099"
 
 # access_log (optional)
 access_log:
   format: "ltsv"
-  path: "/dev/stdout"
+  path: "./access.log" # optional (default: os.Stdout)
   fields: ["time", "time_nsec", "status", "size", "reqtime_nsec", "backend", "path", "query", "method"]
 
-# error_log (required)
+# error_log (optional)
 error_log:
-  path: "/dev/stderr"
+  path: "./error.log" # default: os.Stderr
 
 # exporters: The path of exporter_proxy and the URL of the destination exporter
 exporters:

config/config.go

@@ -17,12 +17,12 @@ type Config struct {
 	ShutDownTimeout *time.Duration            `yaml:"shutdown_timeout"`
 	ExporterConfigs map[string]ExporterConfig `yaml:"exporters" validate:"required,dive"`
 	AccessLogConfig *AccessLogConfig          `yaml:"access_log"`
-	ErrorLogConfig  *ErrorLogConfig           `yaml:"error_log" validate:"required,dive"`
+	ErrorLogConfig  *ErrorLogConfig           `yaml:"error_log"`
 }
 
 type AccessLogConfig struct {
 	Format *string  `yaml:"format" validate:"required"`
-	Path   *string  `yaml:"path" validate:"required"`
+	Path   *string  `yaml:"path"`
 	Fields []string `yaml:"fields" validate:"required"`
 }