Turn off printing IPv6 endpoints when listening on all interfaces (#6986)

By default when we listen on all interfaces, we print all the
endpoints that at local to all interfaces including IPv6
addresses. Remove IPv6 addresses in endpoint list to be
printed in endpoints unless explicitly specified with '--address'

cmd/gateway-startup-msg.go

@@ -55,8 +55,9 @@ func printGatewayCommonMsg(apiEndpoints []string) {
 	cred := globalServerConfig.GetCredential()
 
 	apiEndpointStr := strings.Join(apiEndpoints, "  ")
+
 	// Colorize the message and print.
-	logger.StartupMessage(colorBlue("\nEndpoint: ") + colorBold(fmt.Sprintf(getFormatStr(len(apiEndpointStr), 1), apiEndpointStr)))
+	logger.StartupMessage(colorBlue("Endpoint: ") + colorBold(fmt.Sprintf(getFormatStr(len(apiEndpointStr), 1), apiEndpointStr)))
 	if isTerminal() {
 		logger.StartupMessage(colorBlue("AccessKey: ") + colorBold(fmt.Sprintf("%s ", cred.AccessKey)))
 		logger.StartupMessage(colorBlue("SecretKey: ") + colorBold(fmt.Sprintf("%s ", cred.SecretKey)))

cmd/net.go

@@ -89,7 +89,7 @@ func mustGetLocalIP6() (ipList set.StringSet) {
 			ip = v.IP
 		}
 
-		if ip.To16() != nil {
+		if ip.To4() == nil {
 			ipList.Add(ip.String())
 		}
 	}

cmd/server-startup-msg.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"crypto/x509"
 	"fmt"
+	"net"
 	"runtime"
 	"strings"
 
@@ -76,6 +77,19 @@ func printStartupMessage(apiEndPoints []string) {
 	}
 }
 
+// Returns true if input is not IPv4, false if it is.
+func isNotIPv4(host string) bool {
+	h, _, err := net.SplitHostPort(host)
+	if err != nil {
+		h = host
+	}
+	ip := net.ParseIP(h)
+	ok := ip.To4() != nil // This is always true of IP is IPv4
+
+	// Returns true if input is not IPv4.
+	return !ok
+}
+
 // strip api endpoints list with standard ports such as
 // port "80" and "443" before displaying on the startup
 // banner.  Returns a new list of API endpoints.
@@ -83,12 +97,16 @@ func stripStandardPorts(apiEndpoints []string) (newAPIEndpoints []string) {
 	newAPIEndpoints = make([]string, len(apiEndpoints))
 	// Check all API endpoints for standard ports and strip them.
 	for i, apiEndpoint := range apiEndpoints {
-		url, err := xnet.ParseURL(apiEndpoint)
+		u, err := xnet.ParseURL(apiEndpoint)
 		if err != nil {
 			newAPIEndpoints[i] = apiEndpoint
 			continue
 		}
-		newAPIEndpoints[i] = url.String()
+		if globalMinioHost == "" && isNotIPv4(u.Host) {
+			// Skip all non-IPv4 endpoints when we bind to all interfaces.
+			continue
+		}
+		newAPIEndpoints[i] = u.String()
 	}
 	return newAPIEndpoints
 }