Add samples of proxy middleware

pkg/example/proxy/proxy-server-regex-rewrite/main.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"regexp"
+
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
+)
+
+func main() {
+	e := echo.New()
+
+	target := "http://localhost:8080" // 대상 서버 URL (Tumblebug 서버)
+	url, err := url.Parse(target)
+	if err != nil {
+		e.Logger.Fatal(err)
+	}
+
+	// 정규 표현식 경로 재작성 설정
+	regexRewrite := map[*regexp.Regexp]string{
+		regexp.MustCompile(`^/beetle/ns$`):             "/tumblebug/ns",
+		regexp.MustCompile(`^/beetle/ns/([^/]+)$`):     "/tumblebug/ns/$1",
+		regexp.MustCompile(`^/beetle/ns/([^/]+)/mcis`): "",
+	}
+
+	e.Use(middleware.ProxyWithConfig(middleware.ProxyConfig{
+		Balancer: middleware.NewRoundRobinBalancer([]*middleware.ProxyTarget{
+			{
+				URL: url,
+			},
+		}),
+		RegexRewrite: regexRewrite,
+		ModifyResponse: func(res *http.Response) error {
+			body, err := io.ReadAll(res.Body)
+			if err != nil {
+				return err
+			}
+
+			log.Printf("Response from target: %s", string(body))
+
+			res.Body = io.NopCloser(bytes.NewReader(body))
+			return nil
+		},
+	}))
+
+	// 무시할 경로에 대한 핸들러 추가
+	e.Any("/beetle/ns/:nsId/mcis/*", func(c echo.Context) error {
+		return c.String(http.StatusNotFound, "Not Found")
+	})
+
+	e.Logger.Fatal(e.Start(":1323"))
+}

pkg/example/proxy/proxy-server/main.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
+)
+
+func main() {
+	e := echo.New()
+
+	target := "http://localhost:8080" // target server url
+	url, err := url.Parse(target)
+	if err != nil {
+		e.Logger.Fatal(err)
+	}
+
+	e.Use(middleware.ProxyWithConfig(middleware.ProxyConfig{
+		Balancer: middleware.NewRoundRobinBalancer([]*middleware.ProxyTarget{
+			{
+				URL: url,
+			},
+		}),
+		Skipper: func(c echo.Context) bool {
+			// Skip url patterns that start with /beetle/ns/mcis
+			path := c.Request().URL.Path
+			if strings.HasPrefix(path, "/beetle/ns/") {
+				parts := strings.Split(path, "/")
+				if len(parts) > 3 && parts[3] == "mcis" {
+					return true
+				}
+			}
+			return false
+		},
+		Rewrite: map[string]string{
+			"/beetle/ns":   "/tumblebug/ns",
+			"/beetle/ns/*": "/tumblebug/ns/$1",
+		},
+		ModifyResponse: func(res *http.Response) error {
+			body, err := io.ReadAll(res.Body)
+			if err != nil {
+				return err
+			}
+
+			log.Printf("Response from target: %s", string(body))
+
+			res.Body = io.NopCloser(bytes.NewReader(body))
+			return nil
+		},
+	}))
+
+	e.Logger.Fatal(e.Start(":1323"))
+}

pkg/example/proxy/target-server/main.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/labstack/echo/v4"
+)
+
+func main() {
+	e := echo.New()
+
+	// Pseudo Tumblebug API
+	e.GET("/tumblebug/ns", func(c echo.Context) error {
+		return c.JSON(http.StatusOK, map[string]string{"message": "GET /tumblebug/ns"})
+	})
+
+	e.POST("/tumblebug/ns", func(c echo.Context) error {
+		return c.JSON(http.StatusOK, map[string]string{"message": "POST /tumblebug/ns"})
+	})
+
+	e.DELETE("/tumblebug/ns/:nsId", func(c echo.Context) error {
+		nsId := c.Param("nsId")
+		return c.JSON(http.StatusOK, map[string]string{"message": "DELETE /tumblebug/ns/" + nsId})
+	})
+
+	e.GET("/tumblebug/ns/:nsId", func(c echo.Context) error {
+		nsId := c.Param("nsId")
+		return c.JSON(http.StatusOK, map[string]string{"message": "GET /tumblebug/ns/" + nsId})
+	})
+
+	e.PUT("/tumblebug/ns/:nsId", func(c echo.Context) error {
+		nsId := c.Param("nsId")
+		return c.JSON(http.StatusOK, map[string]string{"message": "PUT /tumblebug/ns/" + nsId})
+	})
+
+	e.Logger.Fatal(e.Start(":8080"))
+}