initial: ZeroTier-like P2P mesh VPN server with multi-tenant Web UI

internal/middleware/logger.go

@@ -0,0 +1,97 @@
+package middleware
+
+import (
+	"bytes"
+	"io"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"zeromesh/internal/model"
+)
+
+type LogWriter interface {
+	InsertApiLog(*model.ApiLog) error
+	InsertErrorLog(*model.ErrorLog) error
+}
+
+type RequestLogger struct {
+	writer LogWriter
+}
+
+func NewRequestLogger(writer LogWriter) *RequestLogger {
+	return &RequestLogger{writer: writer}
+}
+
+func (l *RequestLogger) Handler() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		path := c.Request.URL.Path
+
+		if strings.HasPrefix(path, "/api/v1/log") {
+			c.Next()
+			return
+		}
+
+		start := time.Now()
+
+		body := ""
+		if c.Request.Body != nil {
+			b, _ := io.ReadAll(c.Request.Body)
+			body = string(b)
+			c.Request.Body = io.NopCloser(bytes.NewBuffer(b))
+		}
+
+		blw := &bodyLogWriter{ResponseWriter: c.Writer, buf: &bytes.Buffer{}}
+		c.Writer = blw
+
+		c.Next()
+
+		latencyMs := time.Since(start).Milliseconds()
+		ip := c.ClientIP()
+		method := c.Request.Method
+		query := c.Request.URL.RawQuery
+		ua := c.Request.UserAgent()
+		status := c.Writer.Status()
+
+		if status >= 400 {
+			el := &model.ErrorLog{
+				IP:           ip,
+				Method:       method,
+				Path:         path,
+				StatusCode:   status,
+				Query:        query,
+				UserAgent:    ua,
+				RequestBody:  body,
+				ResponseBody: blw.buf.String(),
+				LatencyMs:    latencyMs,
+			}
+			if err := l.writer.InsertErrorLog(el); err != nil {
+				c.Error(err)
+			}
+		}
+
+		al := &model.ApiLog{
+			IP:         ip,
+			Method:     method,
+			Path:       path,
+			StatusCode: status,
+			Query:      query,
+			UserAgent:  ua,
+			LatencyMs:  latencyMs,
+		}
+		if err := l.writer.InsertApiLog(al); err != nil {
+			c.Error(err)
+		}
+	}
+}
+
+type bodyLogWriter struct {
+	gin.ResponseWriter
+	buf *bytes.Buffer
+}
+
+func (w *bodyLogWriter) Write(b []byte) (int, error) {
+	w.buf.Write(b)
+	return w.ResponseWriter.Write(b)
+}