[improvement/log-levels] Add support set log levels (#301)

README.md

@@ -219,7 +219,7 @@ Assuming that you want to provide a high availability to deal efficiently with,
         |==============|
         |   Balancer   |
         |==============|
-           |       |   
+           |       |
           /         \
          /           \
         /             \
@@ -305,7 +305,7 @@ Options:
   -forward-headers          Forwards custom headers to the image source server. -enable-url-source flag must be defined.
   -enable-url-signature     Enable URL signature (URL-safe Base64-encoded HMAC digest) [default: false]
   -url-signature-key        The URL signature key (32 characters minimum)
-  -allowed-origins <urls>   Restrict remote image source processing to certain origins (separated by commas). Note: Origins are validated against host *AND* path. 
+  -allowed-origins <urls>   Restrict remote image source processing to certain origins (separated by commas). Note: Origins are validated against host *AND* path.
   -max-allowed-size <bytes> Restrict maximum size of http image source (in bytes)
   -certfile <path>          TLS certificate file path
   -keyfile <path>           TLS private key file path
@@ -316,6 +316,8 @@ Options:
   -mrelease <num>           OS memory release interval in seconds [default: 30]
   -cpus <num>               Number of used cpu cores.
                             (default for current machine is 8 cores)
+  -log-level                Set log level for http-server. E.g: info,warning,error [default: info].
+                            Or can use the environment variable GOLANG_LOG=info.
 ```
 
 Start the server in a custom port:
@@ -404,6 +406,11 @@ Or filter debug output by package:
 DEBUG=imaginary imaginary -p 8080
 ```
 
+Disable info logs:
+```
+GOLANG_LOG=error imaginary -p 8080
+```
+
 #### Examples
 
 Reading a local image (you must pass the `-mount=<directory>` flag):

imaginary.go

@@ -49,6 +49,7 @@ var (
 	aBurst              = flag.Int("burst", 100, "Throttle burst max cache size")
 	aMRelease           = flag.Int("mrelease", 30, "OS memory release interval in seconds")
 	aCpus               = flag.Int("cpus", runtime.GOMAXPROCS(-1), "Number of cpu cores to use")
+	aLogLevel           = flag.String("log-level", "info", "Define log level for http-server. E.g: info,warning,error")
 )
 
 const usage = `imaginary %s
@@ -71,6 +72,7 @@ Usage:
   imaginary -v | -version
 
 Options:
+
   -a <addr>                  Bind address [default: *]
   -p <port>                  Bind port [default: 8088]
   -h, -help                  Show help
@@ -102,6 +104,8 @@ Options:
   -mrelease <num>            OS memory release interval in seconds [default: 30]
   -cpus <num>                Number of used cpu cores.
                              (default for current machine is %d cores)
+  -log-level                 Set log level for http-server. E.g: info,warning,error [default: info].
+                             Or can use the environment variable GOLANG_LOG=info.
 `
 
 type URLSignature struct {
@@ -152,6 +156,7 @@ func main() {
 		ForwardHeaders:     parseForwardHeaders(*aForwardHeaders),
 		AllowedOrigins:     parseOrigins(*aAllowedOrigins),
 		MaxAllowedSize:     *aMaxAllowedSize,
+		LogLevel:           getLogLevel(*aLogLevel),
 	}
 
 	// Show warning if gzip flag is passed
@@ -238,6 +243,13 @@ func getURLSignature(key string) URLSignature {
 	return URLSignature{key}
 }
 
+func getLogLevel(logLevel string) string {
+	if logLevelEnv := os.Getenv("GOLANG_LOG"); logLevelEnv != "" {
+		logLevel = logLevelEnv
+	}
+	return logLevel
+}
+
 func showUsage() {
 	flag.Usage()
 	os.Exit(1)

log.go

@@ -44,13 +44,14 @@ func (r *LogRecord) WriteHeader(status int) {
 
 // LogHandler maps the HTTP handler with a custom io.Writer compatible stream
 type LogHandler struct {
-	handler http.Handler
-	io      io.Writer
+	handler    http.Handler
+	io         io.Writer
+	logLevel   string
 }
 
 // NewLog creates a new logger
-func NewLog(handler http.Handler, io io.Writer) http.Handler {
-	return &LogHandler{handler, io}
+func NewLog(handler http.Handler, io io.Writer, logLevel string) http.Handler {
+	return &LogHandler{handler, io, logLevel}
 }
 
 // Implements the required method as standard HTTP handler, serving the request.
@@ -78,5 +79,16 @@ func (h *LogHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	record.time = finishTime.UTC()
 	record.elapsedTime = finishTime.Sub(startTime)
 
-	record.Log(h.io)
+	switch h.logLevel{
+	case "error":
+		if record.status >= http.StatusInternalServerError {
+			record.Log(h.io)
+		}
+	case "warning":
+		if record.status >= http.StatusBadRequest {
+			record.Log(h.io)
+		}
+	case "info":
+		record.Log(h.io)
+	}
 }

log_test.go

@@ -13,7 +13,7 @@ func (fake fakeWriter) Write(buf []byte) (int, error) {
 	return fake(buf)
 }
 
-func TestLog(t *testing.T) {
+func TestLogInfo(t *testing.T) {
 	var buf []byte
 	writer := fakeWriter(func(b []byte) (int, error) {
 		buf = b
@@ -21,7 +21,7 @@ func TestLog(t *testing.T) {
 	})
 
 	noopHandler := func(w http.ResponseWriter, r *http.Request) {}
-	log := NewLog(http.HandlerFunc(noopHandler), writer)
+	log := NewLog(http.HandlerFunc(noopHandler), writer, "info")
 
 	ts := httptest.NewServer(log)
 	defer ts.Close()
@@ -38,3 +38,27 @@ func TestLog(t *testing.T) {
 		t.Fatalf("Invalid log output: %s", data)
 	}
 }
+
+func TestLogError(t *testing.T) {
+	var buf []byte
+	writer := fakeWriter(func(b []byte) (int, error) {
+		buf = b
+		return 0, nil
+	})
+
+	noopHandler := func(w http.ResponseWriter, r *http.Request) {}
+	log := NewLog(http.HandlerFunc(noopHandler), writer, "error")
+
+	ts := httptest.NewServer(log)
+	defer ts.Close()
+
+	_, err := http.Get(ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	data := string(buf)
+	if data != "" {
+		t.Fatalf("Invalid log output: %s", data)
+	}
+}

server.go

@@ -38,6 +38,7 @@ type ServerOptions struct {
 	PlaceholderImage   []byte
 	Endpoints          Endpoints
 	AllowedOrigins     []*url.URL
+	LogLevel           string
 }
 
 // Endpoints represents a list of endpoint names to disable.
@@ -57,7 +58,7 @@ func (e Endpoints) IsValid(r *http.Request) bool {
 
 func Server(o ServerOptions) error {
 	addr := o.Address + ":" + strconv.Itoa(o.Port)
-	handler := NewLog(NewServerMux(o), os.Stdout)
+	handler := NewLog(NewServerMux(o), os.Stdout, o.LogLevel)
 
 	server := &http.Server{
 		Addr:           addr,