Introduce an unexported newBrokerChannelFromConfig

A follow-up wants to pass in a new property from the ClientConfig but it
would be an API breaking change to NewBrokerChannel.

However, it's unclear why NewBrokerChannel is exported at all.  No other
package in the repo depends on it and the known users of the library
probably wouldn't be construct them.

While this patch was being reviewed, a new constructor was added,
NewBrokerChannelWithUTLSSettings, with effectively the same issue.
Both of those exported ones are deleted here.

2 files changed, 17 insertions, 25 deletions

diff --git a/client/lib/rendezvous.go b/client/lib/rendezvous.go
index e7543ad..73c62ed 100644
--- a/client/lib/rendezvous.go
+++ b/client/lib/rendezvous.go
@@ -55,40 +55,34 @@ func createBrokerTransport() http.RoundTripper {
 	return transport
 }
 
-func NewBrokerChannel(broker, ampCache, front string, keepLocalAddresses bool) (*BrokerChannel, error) {
-	return NewBrokerChannelWithUTLSSettings(broker, ampCache, front, keepLocalAddresses, "", false)
-}
+func newBrokerChannelFromConfig(config ClientConfig) (*BrokerChannel, error) {
+	log.Println("Rendezvous using Broker at:", config.BrokerURL)
 
-// NewBrokerChannelWithUTLSSettings construct a new BrokerChannel, where:
-// |broker| is the full URL of the facilitating program which assigns proxies
-// to clients, and |front| is the option fronting domain.
-func NewBrokerChannelWithUTLSSettings(broker, ampCache, front string, keepLocalAddresses bool,
-	uTLSClientID string, removeSNI bool) (*BrokerChannel, error) {
-	log.Println("Rendezvous using Broker at:", broker)
-	if ampCache != "" {
-		log.Println("Through AMP cache at:", ampCache)
-	}
-	if front != "" {
-		log.Println("Domain fronting using:", front)
+	if config.FrontDomain != "" {
+		log.Println("Domain fronting using:", config.FrontDomain)
 	}
 
 	brokerTransport := createBrokerTransport()
 
-	if uTLSClientID != "" {
-		utlsClientHelloID, err := utlsutil.NameToUTLSID(uTLSClientID)
+	if config.UTLSClientID != "" {
+		utlsClientHelloID, err := utlsutil.NameToUTLSID(config.UTLSClientID)
 		if err != nil {
 			return nil, fmt.Errorf("unable to create broker channel: %v", err)
 		}
-		config := &utls.Config{}
-		brokerTransport = utlsutil.NewUTLSHTTPRoundTripper(utlsClientHelloID, config, brokerTransport, removeSNI)
+		utlsConfig := &utls.Config{}
+		brokerTransport = utlsutil.NewUTLSHTTPRoundTripper(utlsClientHelloID, utlsConfig, brokerTransport, config.UTLSRemoveSNI)
 	}
 
 	var rendezvous RendezvousMethod
 	var err error
-	if ampCache != "" {
-		rendezvous, err = newAMPCacheRendezvous(broker, ampCache, front, brokerTransport)
+	if config.AmpCacheURL != "" {
+		log.Println("Through AMP cache at:", config.AmpCacheURL)
+		rendezvous, err = newAMPCacheRendezvous(
+			config.BrokerURL, config.AmpCacheURL, config.FrontDomain,
+			brokerTransport)
 	} else {
-		rendezvous, err = newHTTPRendezvous(broker, front, brokerTransport)
+		rendezvous, err = newHTTPRendezvous(
+			config.BrokerURL, config.FrontDomain, brokerTransport)
 	}
 	if err != nil {
 		return nil, err
@@ -96,7 +90,7 @@ func NewBrokerChannelWithUTLSSettings(broker, ampCache, front string, keepLocalA
 
 	return &BrokerChannel{
 		Rendezvous:         rendezvous,
-		keepLocalAddresses: keepLocalAddresses,
+		keepLocalAddresses: config.KeepLocalAddresses,
 		natType:            nat.NATUnknown,
 	}, nil
 }
diff --git a/client/lib/snowflake.go b/client/lib/snowflake.go
index 1c6c381..1b236a6 100644
--- a/client/lib/snowflake.go
+++ b/client/lib/snowflake.go
@@ -131,9 +131,7 @@ func NewSnowflakeClient(config ClientConfig) (*Transport, error) {
 	}
 
 	// Rendezvous with broker using the given parameters.
-	broker, err := NewBrokerChannelWithUTLSSettings(
-		config.BrokerURL, config.AmpCacheURL, config.FrontDomain,
-		config.KeepLocalAddresses, config.UTLSClientID, config.UTLSRemoveSNI)
+	broker, err := newBrokerChannelFromConfig(config)
 	if err != nil {
 		return nil, err
 	}