Merge remote-tracking branch 'origin/master' into AGDNS-2202-slog-vol-5

main.go

@@ -67,7 +67,8 @@ type Options struct {
 	EDNSAddr string `yaml:"edns-addr" long:"edns-addr" description:"Send EDNS Client Address"`
 
 	// UpstreamMode determines the logic through which upstreams will be used.
-	UpstreamMode string `yaml:"upstream-mode" long:"upstream-mode" description:"" optional:"yes" optional-value:"load_balance"`
+	// If not specified the [proxy.UpstreamModeLoadBalance] is used.
+	UpstreamMode string `yaml:"upstream-mode" long:"upstream-mode" description:"Upstreams logic mode" optional:"yes" optional-value:"load_balance"`
 
 	// ListenAddrs is the list of server's listen addresses.
 	ListenAddrs []string `yaml:"listen-addrs" short:"l" long:"listen" description:"Listening addresses"`

proxy/config.go

@@ -106,6 +106,7 @@ type Config struct {
 	HTTPSServerName string
 
 	// UpstreamMode determines the logic through which upstreams will be used.
+	// If not specified the [proxy.UpstreamModeLoadBalance] is used.
 	UpstreamMode UpstreamMode
 
 	// UDPListenAddr is the set of UDP addresses to listen for plain
@@ -270,6 +271,15 @@ func (p *Proxy) validateConfig() (err error) {
 		return fmt.Errorf("validating ratelimit: %w", err)
 	}
 
+	switch p.UpstreamMode {
+	case "":
+		// Go on.
+	case UpstreamModeFastestAddr, UpstreamModeLoadBalance, UpstreamModeParallel:
+		// Go on.
+	default:
+		return fmt.Errorf("bad upstream mode: %q", p.UpstreamMode)
+	}
+
 	p.logConfigInfo()
 
 	return nil
@@ -333,6 +343,10 @@ func (p *Proxy) logConfigInfo() {
 	if len(p.BogusNXDomain) > 0 {
 		p.logger.Info("bogus-nxdomain ip specified", "prefix_len", len(p.BogusNXDomain))
 	}
+
+	if p.UpstreamMode != "" {
+		p.logger.Info("upstream mode is set", "mode", p.UpstreamMode)
+	}
 }
 
 // validateListenAddrs returns an error if the addresses are not configured

proxy/proxy.go

@@ -262,8 +262,9 @@ func New(c *Config) (p *Proxy, err error) {
 		p.requestsSema = syncutil.EmptySemaphore{}
 	}
 
-	p.logger.Info("upstream mode is set", "mode", p.UpstreamMode)
-	if p.UpstreamMode == UpstreamModeFastestAddr {
+	if p.UpstreamMode == "" {
+		p.UpstreamMode = UpstreamModeLoadBalance
+	} else if p.UpstreamMode == UpstreamModeFastestAddr {
 		p.fastestAddr = fastip.New(&fastip.Config{
 			Logger:          p.Logger,
 			PingWaitTimeout: p.FastestPingTimeout,