From f2d95bbf8099b19d748cd0d94397bd658abea13e Mon Sep 17 00:00:00 2001
From: Stefan Prodan <stefan.prodan@gmail.com>
Date: Mon, 20 Aug 2018 17:03:07 +0300
Subject: [PATCH] Add logging middleware and log level option

---
 cmd/podinfo/main.go    | 77 ++++++++++++++++++++++++++++--------------
 pkg/api/logging.go     | 31 +++++++++++++++++
 pkg/api/server.go      |  2 ++
 pkg/version/version.go |  2 +-
 4 files changed, 85 insertions(+), 27 deletions(-)
 create mode 100644 pkg/api/logging.go

diff --git a/cmd/podinfo/main.go b/cmd/podinfo/main.go
index 5eec9dd..469676b 100644
--- a/cmd/podinfo/main.go
+++ b/cmd/podinfo/main.go
@@ -21,6 +21,7 @@ func main() {
 	// flags definition
 	fs := pflag.NewFlagSet("default", pflag.ContinueOnError)
 	fs.Int("port", 9898, "port")
+	fs.String("level", "info", "log level debug, info, warn, error, flat or panic")
 	fs.String("backend-url", "", "backend service URL")
 	fs.Duration("http-client-timeout", 2*time.Minute, "client timeout duration")
 	fs.Duration("http-server-timeout", 30*time.Second, "server read and write timeout duration")
@@ -60,33 +61,10 @@ func main() {
 	viper.AutomaticEnv()
 
 	// configure logging
-	zapEncoderConfig := zapcore.EncoderConfig{
-		TimeKey:        "ts",
-		LevelKey:       "level",
-		NameKey:        "logger",
-		CallerKey:      "caller",
-		MessageKey:     "msg",
-		StacktraceKey:  "stacktrace",
-		LineEnding:     zapcore.DefaultLineEnding,
-		EncodeLevel:    zapcore.LowercaseLevelEncoder,
-		EncodeTime:     zapcore.ISO8601TimeEncoder,
-		EncodeDuration: zapcore.SecondsDurationEncoder,
-		EncodeCaller:   zapcore.ShortCallerEncoder,
-	}
-	zapConfig := zap.Config{
-		Level:       zap.NewAtomicLevelAt(zapcore.InfoLevel),
-		Development: false,
-		Sampling: &zap.SamplingConfig{
-			Initial:    100,
-			Thereafter: 100,
-		},
-		Encoding:         "json",
-		EncoderConfig:    zapEncoderConfig,
-		OutputPaths:      []string{"stderr"},
-		ErrorOutputPaths: []string{"stderr"},
-	}
-	logger, _ := zapConfig.Build()
+	logger, _ := initZap(viper.GetString("level"))
 	defer logger.Sync()
+	stdLog := zap.RedirectStdLog(logger)
+	defer stdLog()
 
 	// log version and port
 	logger.Info("Starting podinfo",
@@ -119,6 +97,53 @@ func main() {
 	srv.ListenAndServe(stopCh)
 }
 
+func initZap(logLevel string) (*zap.Logger, error) {
+	level := zap.NewAtomicLevelAt(zapcore.InfoLevel)
+	switch logLevel {
+	case "debug":
+		level = zap.NewAtomicLevelAt(zapcore.DebugLevel)
+	case "info":
+		level = zap.NewAtomicLevelAt(zapcore.InfoLevel)
+	case "warn":
+		level = zap.NewAtomicLevelAt(zapcore.WarnLevel)
+	case "error":
+		level = zap.NewAtomicLevelAt(zapcore.ErrorLevel)
+	case "fatal":
+		level = zap.NewAtomicLevelAt(zapcore.FatalLevel)
+	case "panic":
+		level = zap.NewAtomicLevelAt(zapcore.PanicLevel)
+	}
+
+	zapEncoderConfig := zapcore.EncoderConfig{
+		TimeKey:        "ts",
+		LevelKey:       "level",
+		NameKey:        "logger",
+		CallerKey:      "caller",
+		MessageKey:     "msg",
+		StacktraceKey:  "stacktrace",
+		LineEnding:     zapcore.DefaultLineEnding,
+		EncodeLevel:    zapcore.LowercaseLevelEncoder,
+		EncodeTime:     zapcore.ISO8601TimeEncoder,
+		EncodeDuration: zapcore.SecondsDurationEncoder,
+		EncodeCaller:   zapcore.ShortCallerEncoder,
+	}
+
+	zapConfig := zap.Config{
+		Level:       level,
+		Development: false,
+		Sampling: &zap.SamplingConfig{
+			Initial:    100,
+			Thereafter: 100,
+		},
+		Encoding:         "json",
+		EncoderConfig:    zapEncoderConfig,
+		OutputPaths:      []string{"stderr"},
+		ErrorOutputPaths: []string{"stderr"},
+	}
+
+	return zapConfig.Build()
+}
+
 var stressMemoryPayload []byte
 
 func beginStressTest(cpus int, mem int, logger *zap.Logger) {
diff --git a/pkg/api/logging.go b/pkg/api/logging.go
new file mode 100644
index 0000000..47e5c2b
--- /dev/null
+++ b/pkg/api/logging.go
@@ -0,0 +1,31 @@
+package api
+
+import (
+	"net/http"
+
+	"go.uber.org/zap"
+)
+
+type LoggingMiddleware struct {
+	logger *zap.Logger
+}
+
+func NewLoggingMiddleware(logger *zap.Logger) *LoggingMiddleware {
+	return &LoggingMiddleware{
+		logger: logger,
+	}
+}
+
+func (m *LoggingMiddleware) Handler(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		m.logger.Debug(
+			"request started",
+			zap.String("proto", r.Proto),
+			zap.String("uri", r.RequestURI),
+			zap.String("method", r.Method),
+			zap.String("remote", r.RemoteAddr),
+			zap.String("user-agent", r.UserAgent()),
+		)
+		next.ServeHTTP(w, r)
+	})
+}
diff --git a/pkg/api/server.go b/pkg/api/server.go
index d35b5de..37055af 100644
--- a/pkg/api/server.go
+++ b/pkg/api/server.go
@@ -76,6 +76,8 @@ func (s *Server) registerHandlers() {
 func (s *Server) registerMiddlewares() {
 	prom := NewPrometheusMiddleware()
 	s.router.Use(prom.Handler)
+	zapLog := NewLoggingMiddleware(s.logger)
+	s.router.Use(zapLog.Handler)
 	s.router.Use(versionMiddleware)
 }
 
diff --git a/pkg/version/version.go b/pkg/version/version.go
index 4961393..2d9f563 100644
--- a/pkg/version/version.go
+++ b/pkg/version/version.go
@@ -1,4 +1,4 @@
 package version
 
-var VERSION = "1.0.0-alpha.1"
+var VERSION = "1.0.0-alpha.2"
 var REVISION = "unknown"