Updated handler config (#63)

vendor/github.com/labstack/echo/middleware/proxy.go

@@ -6,7 +6,6 @@ import (
 	"math/rand"
 	"net"
 	"net/http"
-	"net/http/httputil"
 	"net/url"
 	"regexp"
 	"strings"
@@ -38,6 +37,14 @@ type (
 		// "/users/*/orders/*": "/user/$1/order/$2",
 		Rewrite map[string]string
 
+    // Context key to store selected ProxyTarget into context.
+		// Optional. Default value "target".
+		ContextKey string
+
+    // To customize the transport to remote.
+		// Examples: If custom TLS certificates are required.
+		Transport http.RoundTripper
+
 		rewriteRegex map[*regexp.Regexp]string
 	}
 
@@ -45,13 +52,14 @@ type (
 	ProxyTarget struct {
 		Name string
 		URL  *url.URL
+		Meta echo.Map
 	}
 
 	// ProxyBalancer defines an interface to implement a load balancing technique.
 	ProxyBalancer interface {
 		AddTarget(*ProxyTarget) bool
 		RemoveTarget(string) bool
-		Next() *ProxyTarget
+		Next(echo.Context) *ProxyTarget
 	}
 
 	commonBalancer struct {
@@ -75,14 +83,11 @@ type (
 var (
 	// DefaultProxyConfig is the default Proxy middleware config.
 	DefaultProxyConfig = ProxyConfig{
-		Skipper: DefaultSkipper,
+		Skipper:    DefaultSkipper,
+		ContextKey: "target",
 	}
 )
 
-func proxyHTTP(t *ProxyTarget) http.Handler {
-	return httputil.NewSingleHostReverseProxy(t.URL)
-}
-
 func proxyRaw(t *ProxyTarget, c echo.Context) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		in, _, err := c.Response().Hijack()
@@ -164,7 +169,7 @@ func (b *commonBalancer) RemoveTarget(name string) bool {
 }
 
 // Next randomly returns an upstream target.
-func (b *randomBalancer) Next() *ProxyTarget {
+func (b *randomBalancer) Next(c echo.Context) *ProxyTarget {
 	if b.random == nil {
 		b.random = rand.New(rand.NewSource(int64(time.Now().Nanosecond())))
 	}
@@ -174,7 +179,7 @@ func (b *randomBalancer) Next() *ProxyTarget {
 }
 
 // Next returns an upstream target using round-robin technique.
-func (b *roundRobinBalancer) Next() *ProxyTarget {
+func (b *roundRobinBalancer) Next(c echo.Context) *ProxyTarget {
 	b.i = b.i % uint32(len(b.targets))
 	t := b.targets[b.i]
 	atomic.AddUint32(&b.i, 1)
@@ -216,7 +221,8 @@ func ProxyWithConfig(config ProxyConfig) echo.MiddlewareFunc {
 
 			req := c.Request()
 			res := c.Response()
-			tgt := config.Balancer.Next()
+			tgt := config.Balancer.Next(c)
+			c.Set(config.ContextKey, tgt)
 
 			// Rewrite
 			for k, v := range config.rewriteRegex {
@@ -243,7 +249,7 @@ func ProxyWithConfig(config ProxyConfig) echo.MiddlewareFunc {
 				proxyRaw(tgt, c).ServeHTTP(res, req)
 			case req.Header.Get(echo.HeaderAccept) == "text/event-stream":
 			default:
-				proxyHTTP(tgt).ServeHTTP(res, req)
+				proxyHTTP(tgt, c, config).ServeHTTP(res, req)
 			}
 
 			return