Add metadata Get method (#1425)

metadata/metadata.go

@@ -13,6 +13,18 @@ type metaKey struct{}
 // from Transport headers.
 type Metadata map[string]string
 
+func (md Metadata) Get(key string) (string, bool) {
+	// attempt to get as is
+	val, ok := md[key]
+	if ok {
+		return val, ok
+	}
+
+	// attempt to get lower case
+	val, ok = md[strings.Title(key)]
+	return val, ok
+}
+
 // Copy makes a copy of the metadata
 func Copy(md Metadata) Metadata {
 	cmd := make(Metadata)

proxy/mucp/mucp.go

@@ -120,7 +120,7 @@ func (p *Proxy) filterRoutes(ctx context.Context, routes []router.Route) []route
 	// filter the routes based on our headers
 	for _, route := range routes {
 		// process only routes for this id
-		if id := md["Micro-Router"]; len(id) > 0 {
+		if id, ok := md.Get("Micro-Router"); ok && len(id) > 0 {
 			if route.Router != id {
 				// skip routes that don't mwatch
 				continue
@@ -128,7 +128,7 @@ func (p *Proxy) filterRoutes(ctx context.Context, routes []router.Route) []route
 		}
 
 		// only process routes with this network
-		if net := md["Micro-Network"]; len(net) > 0 {
+		if net, ok := md.Get("Micro-Network"); ok && len(net) > 0 {
 			if route.Network != net {
 				// skip routes that don't mwatch
 				continue
@@ -136,7 +136,7 @@ func (p *Proxy) filterRoutes(ctx context.Context, routes []router.Route) []route
 		}
 
 		// process only this gateway
-		if gw := md["Micro-Gateway"]; len(gw) > 0 {
+		if gw, ok := md.Get("Micro-Gateway"); ok && len(gw) > 0 {
 			// if the gateway matches our address
 			// special case, take the routes with no gateway
 			// TODO: should we strip the gateway from the context?