make the TestRPC_RPCMaxConnsPerClient test less flaky (#7255)

agent/consul/rpc_test.go

@@ -631,7 +631,13 @@ func TestRPC_RPCMaxConnsPerClient(t *testing.T) {
 			defer conn3.Close()
 
 			// If we close one of the earlier ones, we should be able to open another
+			addr := conn1.RemoteAddr()
 			conn1.Close()
+			retry.Run(t, func(r *retry.R) {
+				if n := s1.rpcConnLimiter.NumOpen(addr); n >= 2 {
+					r.Fatal("waiting for open conns to drop")
+				}
+			})
 			conn4 := connectClient(t, s1, tc.magicByte, tc.tlsEnabled, true, "conn4")
 			defer conn4.Close()
 

go.mod

@@ -32,7 +32,7 @@ require (
 	github.com/hashicorp/go-bexpr v0.1.2
 	github.com/hashicorp/go-checkpoint v0.0.0-20171009173528-1545e56e46de
 	github.com/hashicorp/go-cleanhttp v0.5.1
-	github.com/hashicorp/go-connlimit v0.1.0
+	github.com/hashicorp/go-connlimit v0.2.0
 	github.com/hashicorp/go-discover v0.0.0-20191202160150-7ec2cfbda7a2
 	github.com/hashicorp/go-hclog v0.12.0
 	github.com/hashicorp/go-memdb v1.0.3

go.sum

@@ -122,8 +122,8 @@ github.com/hashicorp/go-checkpoint v0.0.0-20171009173528-1545e56e46de/go.mod h1:
 github.com/hashicorp/go-cleanhttp v0.5.0/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
 github.com/hashicorp/go-cleanhttp v0.5.1 h1:dH3aiDG9Jvb5r5+bYHsikaOUIpcM0xvgMXVoDkXMzJM=
 github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
-github.com/hashicorp/go-connlimit v0.1.0 h1:j8XwYaCBgm7n82jaQpaUeaDlsJH1x5/ycAJhlkrXv7E=
-github.com/hashicorp/go-connlimit v0.1.0/go.mod h1:OUj9FGL1tPIhl/2RCfzYHrIiWj+VVPGNyVPnUX8AqS0=
+github.com/hashicorp/go-connlimit v0.2.0 h1:OZjcfNxH/hPh/bT2Iw5yOJcLzz+zuIWpsp3I1S4Pjw4=
+github.com/hashicorp/go-connlimit v0.2.0/go.mod h1:OUj9FGL1tPIhl/2RCfzYHrIiWj+VVPGNyVPnUX8AqS0=
 github.com/hashicorp/go-discover v0.0.0-20191202160150-7ec2cfbda7a2 h1:r7GtRT+VXoM5WqHMxSVDIKgVCfK9T8CoS51RDKeOjBM=
 github.com/hashicorp/go-discover v0.0.0-20191202160150-7ec2cfbda7a2/go.mod h1:NnH5X4UCBEBdTuK2L8s4e4ilJm3UmGX0bANHCz0HSs0=
 github.com/hashicorp/go-hclog v0.0.0-20180709165350-ff2cf002a8dd/go.mod h1:9bjs9uLqI8l75knNv3lV1kA55veR+WUPSiKIWcQHudI=

vendor/github.com/hashicorp/go-connlimit/connlimit.go

@@ -64,7 +64,7 @@ func NewLimiter(cfg Config) *Limiter {
 // or transient failure to read or parse the remote IP. The free func will be a
 // no-op in this case and need not be called.
 func (l *Limiter) Accept(conn net.Conn) (func(), error) {
-	addrKey := addrKey(conn)
+	addrKey := connKey(conn)
 
 	// Load config outside locked section since it's not updated under lock anyway
 	// and the atomic Load might be slower/contented so better to do outside lock.
@@ -101,8 +101,29 @@ func (l *Limiter) Accept(conn net.Conn) (func(), error) {
 	return free, nil
 }
 
-func addrKey(conn net.Conn) string {
-	addr := conn.RemoteAddr()
+func (l *Limiter) NumOpen(addr net.Addr) int {
+	addrKey := addrKey(addr)
+
+	l.l.Lock()
+	defer l.l.Unlock()
+
+	if l.cs == nil {
+		return 0
+	}
+
+	cs := l.cs[addrKey]
+	if cs == nil {
+		return 0
+	}
+
+	return len(cs)
+}
+
+func connKey(conn net.Conn) string {
+	return addrKey(conn.RemoteAddr())
+}
+
+func addrKey(addr net.Addr) string {
 	switch a := addr.(type) {
 	case *net.TCPAddr:
 		return "ip:" + a.IP.String()
@@ -119,7 +140,7 @@ func addrKey(conn net.Conn) string {
 // freeConn removes a connection from the map if it's present. It is a no-op if
 // the conn was never accepted by Accept.
 func (l *Limiter) freeConn(conn net.Conn) {
-	addrKey := addrKey(conn)
+	addrKey := connKey(conn)
 
 	l.l.Lock()
 	defer l.l.Unlock()

vendor/modules.txt

@@ -177,7 +177,7 @@ github.com/hashicorp/go-bexpr
 github.com/hashicorp/go-checkpoint
 # github.com/hashicorp/go-cleanhttp v0.5.1
 github.com/hashicorp/go-cleanhttp
-# github.com/hashicorp/go-connlimit v0.1.0
+# github.com/hashicorp/go-connlimit v0.2.0
 github.com/hashicorp/go-connlimit
 # github.com/hashicorp/go-discover v0.0.0-20191202160150-7ec2cfbda7a2
 github.com/hashicorp/go-discover