New version

npmproxy/externalProxy.go

@@ -0,0 +1,92 @@
+package npmproxy
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"strings"
+	"time"
+
+	"github.com/kataras/golog"
+)
+
+func (p *Proxy) externalHTTPServer(ctx context.Context) {
+	mux := http.NewServeMux()
+
+	srv := &http.Server{
+		Addr:    p.externalProxyHost,
+		Handler: mux,
+	}
+
+	go func() {
+		<-ctx.Done()
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+
+		if err := srv.Shutdown(shutdownCtx); err != nil {
+			fmt.Printf("Failed to shutdown proxy server: %v\n", err)
+		}
+	}()
+
+	mux.HandleFunc("/", p.incomingNpmRequestHandler)
+
+	if err := srv.ListenAndServe(); err != nil {
+		if err != http.ErrServerClosed {
+			panic(err)
+		}
+	}
+}
+
+// Receives incoming requests from the npm cli and decides based on override rules what server it should forwarded to.
+func (p *Proxy) incomingNpmRequestHandler(res http.ResponseWriter, req *http.Request) {
+	golog.Infof("Incoming NPM request for %s", req.URL.Path)
+	pkgPath := strings.TrimLeft(req.URL.Path, "/")
+
+	// If no matching override is found, we forward the request to the default registry.
+	_, ok := p.matchingOverride(pkgPath)
+	if !ok {
+		serveReverseProxy(p.DefaultRegistry, res, req)
+		return
+	}
+
+	// Process the override by forwarding the request to the internal proxy.
+
+	serveReverseProxy(p.internalProxyUrl, res, req)
+
+	// golog.Infof("Received request for url: %v", proxyUrl)
+}
+
+type ResponseWriterWrapper struct {
+	http.ResponseWriter
+	Body *bytes.Buffer
+}
+
+func (rw *ResponseWriterWrapper) Write(b []byte) (int, error) {
+	rw.Body.Write(b)                  // Capture the response body
+	return rw.ResponseWriter.Write(b) // Send the response to the original writer
+}
+
+func serveReverseProxy(target string, res http.ResponseWriter, req *http.Request) {
+	// parse the OriginalUrl
+	OriginalUrl, _ := url.Parse(target)
+
+	// create the reverse proxy
+	proxy := httputil.NewSingleHostReverseProxy(OriginalUrl)
+
+	// Update the headers to allow for SSL redirection
+	req.URL.Host = OriginalUrl.Host
+	req.URL.Scheme = OriginalUrl.Scheme
+	req.Header.Set("X-Forwarded-Host", req.Header.Get("Host"))
+	req.Host = OriginalUrl.Host
+
+	wrappedRes := &ResponseWriterWrapper{ResponseWriter: res, Body: new(bytes.Buffer)}
+
+	// Note that ServeHttp is non blocking and uses a go routine under the hood
+	proxy.ServeHTTP(wrappedRes, req)
+
+	// Print the captured response body
+	fmt.Println("Response body:", wrappedRes.Body.String())
+}