feat(proxy): make the hostname of PMS configurable

Author: RoyXiang

handler/main.go

@@ -21,6 +21,7 @@ var (
 func init() {
 	plexClient = NewPlexClient(PlexConfig{
 		BaseUrl:          os.Getenv("PLEX_BASEURL"),
+		Hostname:         os.Getenv("PLEX_HOSTNAME"),
 		Token:            os.Getenv("PLEX_TOKEN"),
 		PlaxtUrl:         os.Getenv("PLAXT_URL"),
 		RedirectWebApp:   os.Getenv("REDIRECT_WEB_APP"),

handler/plex.go

@@ -20,6 +20,7 @@ import (
 
 type PlexConfig struct {
 	BaseUrl          string
+	Hostname         string
 	Token            string
 	PlaxtUrl         string
 	RedirectWebApp   string
@@ -53,12 +54,7 @@ func NewPlexClient(config PlexConfig) *PlexClient {
 		return nil
 	}
 
-	proxy := httputil.NewSingleHostReverseProxy(u)
-	proxy.FlushInterval = -1
-	proxy.ErrorLog = common.GetLogger()
-	proxy.ModifyResponse = modifyResponse
-	proxy.ErrorHandler = proxyErrorHandler
-
+	proxy := newSingleHostReverseProxy(u, config.Hostname)
 	client, _ := plex.New(config.BaseUrl, config.Token)
 
 	var plaxtUrl string

handler/utils.go

@@ -9,9 +9,72 @@ import (
 	"strings"
 	"time"
 
+	"github.com/RoyXiang/plexproxy/common"
 	"github.com/go-chi/chi/v5/middleware"
 )
 
+func newSingleHostReverseProxy(target *url.URL, hostname string) *httputil.ReverseProxy {
+	targetQuery := target.RawQuery
+	director := func(req *http.Request) {
+		req.URL.Scheme = target.Scheme
+		if hostname != "" {
+			req.URL.Host = hostname
+		} else {
+			req.URL.Host = target.Host
+		}
+		req.URL.Path, req.URL.RawPath = joinURLPath(target, req.URL)
+		if targetQuery == "" || req.URL.RawQuery == "" {
+			req.URL.RawQuery = targetQuery + req.URL.RawQuery
+		} else {
+			req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+		}
+		if _, ok := req.Header["User-Agent"]; !ok {
+			// explicitly disable User-Agent so it's not set to default value
+			req.Header.Set("User-Agent", "")
+		}
+	}
+	proxy := &httputil.ReverseProxy{Director: director}
+
+	proxy.FlushInterval = -1
+	proxy.ErrorLog = common.GetLogger()
+	proxy.ModifyResponse = modifyResponse
+	proxy.ErrorHandler = proxyErrorHandler
+	return proxy
+}
+
+func joinURLPath(a, b *url.URL) (path, rawpath string) {
+	if a.RawPath == "" && b.RawPath == "" {
+		return singleJoiningSlash(a.Path, b.Path), ""
+	}
+	// Same as singleJoiningSlash, but uses EscapedPath to determine
+	// whether a slash should be added
+	apath := a.EscapedPath()
+	bpath := b.EscapedPath()
+
+	aslash := strings.HasSuffix(apath, "/")
+	bslash := strings.HasPrefix(bpath, "/")
+
+	switch {
+	case aslash && bslash:
+		return a.Path + b.Path[1:], apath + bpath[1:]
+	case !aslash && !bslash:
+		return a.Path + "/" + b.Path, apath + "/" + bpath
+	}
+	return a.Path + b.Path, apath + bpath
+}
+
+func singleJoiningSlash(a, b string) string {
+	aslash := strings.HasSuffix(a, "/")
+	bslash := strings.HasPrefix(b, "/")
+	switch {
+	case aslash && bslash:
+		return a + b[1:]
+	case !aslash && !bslash:
+		return a + "/" + b
+	}
+	return a + b
+}
+
 func wrapResponseWriter(w http.ResponseWriter, protoMajor int) middleware.WrapResponseWriter {
 	if nw, ok := w.(middleware.WrapResponseWriter); ok {
 		return nw