move filteredPROXYListener wrapping to Listen()

caddyhttp/httpserver/proxyprotocol.go

@@ -7,11 +7,12 @@ import (
 	"time"
 
 	"github.com/armon/go-proxyproto"
+	"github.com/mholt/caddy"
 )
 
 // filteredPROXYListener suports the Proxy Protocol on accepted sockets, and implements the `net.Listener` interface.
 type filteredPROXYListener struct {
-	net.Listener
+	caddy.Listener
 	timeout time.Duration
 	subnets []*net.IPNet
 }
@@ -20,7 +21,7 @@ type filteredPROXYListener struct {
 // zero for no timeout, or provide a timeout for receiving the PROXY header. `subnets` is a comma-delimited list of CIDR
 // ranges, for which to accept PROXY headers. If a new connection does not originate from one of the ranges, it will not be processed
 // for a PROXY header. If the CIDR ranges are invalid or cannot be parsed, an error is returned.
-func newFilteredPROXYListener(ln net.Listener, headerTimeout time.Duration, subnets string) (*filteredPROXYListener, error) {
+func newFilteredPROXYListener(ln caddy.Listener, headerTimeout time.Duration, subnets string) (*filteredPROXYListener, error) {
 	cidrs := strings.Split(subnets, ",")
 	s := make([]*net.IPNet, len(cidrs))
 	var err error

caddyhttp/httpserver/server.go

@@ -146,9 +146,23 @@ func (s *Server) Listen() (net.Listener, error) {
 		}
 	}
 
+	if ProxyProtocolSubnets != "" {
+		// need to wrap this now, because Serve won't if it doesn't get a *net.TCPListener struct
+		tln := tcpKeepAliveListener{TCPListener: ln.(*net.TCPListener)}
+
+		// We decode proxy protocol after the TCP wrapper, but before
+		// anything else. As long as the wrapper happens before things
+		// that care about RemoteAddr, we should be ok.
+		fln, err := newFilteredPROXYListener(tln, ProxyProtocolTimeout, ProxyProtocolSubnets)
+		if err != nil {
+			return nil, fmt.Errorf("configuring Proxy Protocol support: %v", err)
+		}
+		ln = fln
+	}
+
 	// Very important to return a concrete caddy.Listener
 	// implementation for graceful restarts.
-	return ln.(*net.TCPListener), nil
+	return ln.(caddy.Listener), nil
 }
 
 // ListenPacket is a noop to implement the Server interface.
@@ -160,18 +174,6 @@ func (s *Server) Serve(ln net.Listener) error {
 		ln = tcpKeepAliveListener{TCPListener: tcpLn}
 	}
 
-	if ProxyProtocolSubnets != "" {
-		// We decode proxy protocol after the TCP wrapper, but before
-		// anything else. As long as the wrapper happens before things
-		// that care about RemoteAddr, we should be ok.
-		fln, err := newFilteredPROXYListener(ln, ProxyProtocolTimeout, ProxyProtocolSubnets)
-		if err != nil {
-			fmt.Printf("[ERROR] configuring Proxy Protocol support: %v\n", err)
-		} else {
-			ln = fln
-		}
-	}
-
 	ln = newGracefulListener(ln, &s.connWg)
 
 	s.listenerMu.Lock()