Pass a logger to ConnPool and yamux, instead of an io.Writer

Allowing us to remove the LogOutput field from config.

agent/agent.go

@@ -591,16 +591,10 @@ func (a *Agent) initializeConnectionPool() error {
 		rpcSrcAddr = &net.TCPAddr{IP: a.config.RPCBindAddr.IP}
 	}
 
-	// Ensure we have a log output for the connection pool.
-	logOutput := a.LogOutput
-	if logOutput == nil {
-		logOutput = os.Stderr
-	}
-
 	pool := &pool.ConnPool{
 		Server:          a.config.ServerMode,
 		SrcAddr:         rpcSrcAddr,
-		LogOutput:       logOutput,
+		Logger:          a.logger.StandardLogger(&hclog.StandardLoggerOptions{InferLevels: true}),
 		TLSConfigurator: a.tlsConfigurator,
 		Datacenter:      a.config.Datacenter,
 	}

agent/consul/client.go

@@ -140,7 +140,7 @@ func NewClientWithOptions(config *Config, options ...ConsulOption) (*Client, err
 		connPool = &pool.ConnPool{
 			Server:          false,
 			SrcAddr:         config.RPCSrcAddr,
-			LogOutput:       config.LogOutput,
+			Logger:          logger.StandardLogger(&hclog.StandardLoggerOptions{InferLevels: true}),
 			MaxTime:         clientRPCConnMaxIdle,
 			MaxStreams:      clientMaxStreams,
 			TLSConfigurator: tlsConfigurator,

agent/consul/rpc.go

@@ -295,7 +295,10 @@ func (s *Server) handleNativeTLS(conn net.Conn) {
 func (s *Server) handleMultiplexV2(conn net.Conn) {
 	defer conn.Close()
 	conf := yamux.DefaultConfig()
-	conf.LogOutput = s.config.LogOutput
+	// override the default because LogOutput conflicts with Logger
+	conf.LogOutput = nil
+	// TODO: should this be created once and cached?
+	conf.Logger = s.logger.StandardLogger(&hclog.StandardLoggerOptions{InferLevels: true})
 	server, _ := yamux.Server(conn, conf)
 	for {
 		sub, err := server.Accept()

agent/consul/server.go

@@ -400,7 +400,7 @@ func NewServerWithOptions(config *Config, options ...ConsulOption) (*Server, err
 		connPool = &pool.ConnPool{
 			Server:          true,
 			SrcAddr:         config.RPCSrcAddr,
-			LogOutput:       config.LogOutput,
+			Logger:          logger.StandardLogger(&hclog.StandardLoggerOptions{InferLevels: true}),
 			MaxTime:         serverRPCCache,
 			MaxStreams:      serverMaxStreams,
 			TLSConfigurator: tlsConfigurator,

agent/pool/pool.go

@@ -4,7 +4,7 @@ import (
 	"container/list"
 	"crypto/tls"
 	"fmt"
-	"io"
+	"log"
 	"net"
 	"net/rpc"
 	"sync"
@@ -126,8 +126,9 @@ type ConnPool struct {
 	// SrcAddr is the source address for outgoing connections.
 	SrcAddr *net.TCPAddr
 
-	// LogOutput is used to control logging
-	LogOutput io.Writer
+	// Logger passed to yamux
+	// TODO: consider refactoring to accept a full yamux.Config instead of a logger
+	Logger *log.Logger
 
 	// The maximum time to keep a connection open
 	MaxTime time.Duration
@@ -454,9 +455,10 @@ func (p *ConnPool) getNewConn(dc string, nodeName string, addr net.Addr) (*Conn,
 		return nil, err
 	}
 
-	// Setup the logger
 	conf := yamux.DefaultConfig()
-	conf.LogOutput = p.LogOutput
+	// override the default because LogOutput conflicts with Logger.
+	conf.LogOutput = nil
+	conf.Logger = p.Logger
 
 	// Create a multiplexed session
 	session, err := yamux.Client(conn, conf)