From 3389085aa9d08ce552e819028c1fb19439ec98f8 Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Tue, 1 Aug 2023 15:25:20 +0200
Subject: [PATCH 01/17] refactor of the tests so they are not hardcoded

---
 receiver/statsdreceiver/config_test.go        | 14 ++--
 .../internal/transport/client/client.go       | 58 +++++---------
 .../internal/transport/server.go              |  3 -
 .../internal/transport/server_test.go         | 80 +++++++++++--------
 .../internal/transport/transport.go           | 45 +++++++++++
 .../internal/transport/udp_server.go          | 37 +++++----
 receiver/statsdreceiver/receiver.go           | 11 +--
 receiver/statsdreceiver/receiver_test.go      | 29 ++++---
 8 files changed, 158 insertions(+), 119 deletions(-)
 create mode 100644 receiver/statsdreceiver/internal/transport/transport.go

diff --git a/receiver/statsdreceiver/config_test.go b/receiver/statsdreceiver/config_test.go
index 73cad547990b..eefcda88b485 100644
--- a/receiver/statsdreceiver/config_test.go
+++ b/receiver/statsdreceiver/config_test.go
@@ -82,10 +82,12 @@ func TestValidate(t *testing.T) {
 	}
 
 	const (
-		negativeAggregationIntervalErr = "aggregation_interval must be a positive duration"
-		noObjectNameErr                = "must specify object id for all TimerHistogramMappings"
-		statsdTypeNotSupportErr        = "statsd_type is not a supported mapping for histogram and timing metrics: %s"
-		observerTypeNotSupportErr      = "observer_type is not supported for histogram and timing metrics: %s"
+		negativeAggregationIntervalErr      = "aggregation_interval must be a positive duration"
+		noObjectNameErr                     = "must specify object id for all TimerHistogramMappings"
+		statsdTypeNotSupportErr             = "statsd_type is not a supported mapping for histogram and timing metrics: %s"
+		observerTypeNotSupportErr           = "observer_type is not supported for histogram and timing metrics: %s"
+		invalidHistogramErr                 = "histogram configuration requires observer_type: histogram"
+		socketConfigurationWithUDSServerErr = "socket configuration is unsupported if the transport is not a unix domain socket"
 	)
 
 	tests := []test{
@@ -153,7 +155,7 @@ func TestValidate(t *testing.T) {
 					},
 				},
 			},
-			expectedErr: "histogram configuration requires observer_type: histogram",
+			expectedErr: invalidHistogramErr,
 		},
 		{
 			name: "negativeAggregationInterval",
@@ -163,7 +165,7 @@ func TestValidate(t *testing.T) {
 					{StatsdType: "timing", ObserverType: "gauge"},
 				},
 			},
-			expectedErr: "aggregation_interval must be a positive duration",
+			expectedErr: negativeAggregationIntervalErr,
 		},
 	}
 
diff --git a/receiver/statsdreceiver/internal/transport/client/client.go b/receiver/statsdreceiver/internal/transport/client/client.go
index ba40dbcf1deb..3e0121586e78 100644
--- a/receiver/statsdreceiver/internal/transport/client/client.go
+++ b/receiver/statsdreceiver/internal/transport/client/client.go
@@ -7,33 +7,25 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"strings"
 )
 
 // StatsD defines the properties of a StatsD connection.
 type StatsD struct {
-	Host string
-	Port int
-	Conn io.Writer
+	transport string
+	address   string
+	Conn      io.Writer
 }
 
-// Transport is an enum to select the type of transport.
-type Transport int
-
-const (
-	// TCP Transport
-	TCP Transport = iota
-	// UDP Transport
-	UDP
-)
-
 // NewStatsD creates a new StatsD instance to support the need for testing
 // the statsdreceiver package and is not intended/tested to be used in production.
-func NewStatsD(transport Transport, host string, port int) (*StatsD, error) {
+func NewStatsD(transport string, address string) (*StatsD, error) {
 	statsd := &StatsD{
-		Host: host,
-		Port: port,
+		transport: transport,
+		address:   address,
 	}
-	err := statsd.connect(transport)
+
+	err := statsd.connect()
 	if err != nil {
 		return nil, err
 	}
@@ -42,33 +34,22 @@ func NewStatsD(transport Transport, host string, port int) (*StatsD, error) {
 }
 
 // connect populates the StatsD.Conn
-func (s *StatsD) connect(transport Transport) error {
-	if cl, ok := s.Conn.(io.Closer); ok {
-		cl.Close()
-	}
-
-	address := fmt.Sprintf("%s:%d", s.Host, s.Port)
-
-	var err error
-	switch transport {
-	case TCP:
-		// TODO: implement TCP support
-		return fmt.Errorf("TCP unsupported")
-	case UDP:
-		var udpAddr *net.UDPAddr
-		udpAddr, err = net.ResolveUDPAddr("udp", address)
+func (s *StatsD) connect() error {
+	switch s.transport {
+	case "udp":
+		udpAddr, err := net.ResolveUDPAddr(s.transport, s.address)
 		if err != nil {
 			return err
 		}
-		s.Conn, err = net.DialUDP("udp", nil, udpAddr)
+		s.Conn, err = net.DialUDP(s.transport, nil, udpAddr)
 		if err != nil {
 			return err
 		}
 	default:
-		return fmt.Errorf("unknown transport: %d", transport)
+		return fmt.Errorf("unknown/unsupported transport: %s", s.transport)
 	}
 
-	return err
+	return nil
 }
 
 // Disconnect closes the StatsD.Conn.
@@ -83,11 +64,8 @@ func (s *StatsD) Disconnect() error {
 
 // SendMetric sends the input metric to the StatsD connection.
 func (s *StatsD) SendMetric(metric Metric) error {
-	_, err := fmt.Fprint(s.Conn, metric.String())
-	if err != nil {
-		return err
-	}
-	return nil
+	_, err := io.Copy(s.Conn, strings.NewReader(metric.String()))
+	return err
 }
 
 // Metric contains the metric fields for a StatsD message.
diff --git a/receiver/statsdreceiver/internal/transport/server.go b/receiver/statsdreceiver/internal/transport/server.go
index 7b3cdab6006f..c551e4312cd9 100644
--- a/receiver/statsdreceiver/internal/transport/server.go
+++ b/receiver/statsdreceiver/internal/transport/server.go
@@ -9,8 +9,6 @@ import (
 	"net"
 
 	"go.opentelemetry.io/collector/consumer"
-
-	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/protocol"
 )
 
 var errNilListenAndServeParameters = errors.New("no parameter of ListenAndServe can be nil")
@@ -22,7 +20,6 @@ type Server interface {
 	// on the specific transport, and prepares the message to be processed by
 	// the Parser and passed to the next consumer.
 	ListenAndServe(
-		p protocol.Parser,
 		mc consumer.Metrics,
 		r Reporter,
 		transferChan chan<- Metric,
diff --git a/receiver/statsdreceiver/internal/transport/server_test.go b/receiver/statsdreceiver/internal/transport/server_test.go
index 5a7b545a9a75..55b549e31a25 100644
--- a/receiver/statsdreceiver/internal/transport/server_test.go
+++ b/receiver/statsdreceiver/internal/transport/server_test.go
@@ -4,9 +4,9 @@
 package transport
 
 import (
+	"io"
 	"net"
 	"runtime"
-	"strconv"
 	"sync"
 	"testing"
 	"time"
@@ -16,52 +16,39 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumertest"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/common/testutil"
-	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/protocol"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/client"
 )
 
 func Test_Server_ListenAndServe(t *testing.T) {
 	tests := []struct {
-		name          string
-		buildServerFn func(addr string) (Server, error)
-		buildClientFn func(host string, port int) (*client.StatsD, error)
+		name              string
+		buildServerFn     func(transport Transport, addr string) (Server, error)
+		getFreeEndpointFn func(t testing.TB, transport string) string
+		buildClientFn     func(transport string, address string) (*client.StatsD, error)
+		testSkip          bool
 	}{
 		{
-			name:          "udp",
-			buildServerFn: NewUDPServer,
-			buildClientFn: func(host string, port int) (*client.StatsD, error) {
-				return client.NewStatsD(client.UDP, host, port)
-			},
+			name:              "udp",
+			getFreeEndpointFn: testutil.GetAvailableLocalNetworkAddress,
+			buildServerFn:     NewUDPServer,
+			buildClientFn:     client.NewStatsD,
 		},
 	}
 	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			addr := testutil.GetAvailableLocalNetworkAddress(t, "udp")
-
-			// Endpoint should be free.
-			ln0, err := net.ListenPacket("udp", addr)
-			require.NoError(t, err)
-			require.NotNil(t, ln0)
+		if tt.testSkip {
+			continue
+		}
 
-			// Ensure that the endpoint wasn't something like ":0" by checking that a second listener will fail.
-			ln1, err := net.ListenPacket("udp", addr)
-			require.Error(t, err)
-			require.Nil(t, ln1)
-
-			// Unbind the local address so the mock UDP service can use it
-			ln0.Close()
+		t.Run(tt.name, func(t *testing.T) {
+			trans := Transport(tt.name)
+			addr := tt.getFreeEndpointFn(t, tt.name)
+			testFreeEndpoint(t, tt.name, addr)
 
-			srv, err := tt.buildServerFn(addr)
+			srv, err := tt.buildServerFn(trans, addr)
 			require.NoError(t, err)
 			require.NotNil(t, srv)
 
-			host, portStr, err := net.SplitHostPort(addr)
-			require.NoError(t, err)
-			port, err := strconv.Atoi(portStr)
-			require.NoError(t, err)
-
 			mc := new(consumertest.MetricsSink)
-			p := &protocol.StatsDParser{}
 			require.NoError(t, err)
 			mr := NewMockReporter(1)
 			transferChan := make(chan Metric, 10)
@@ -70,12 +57,12 @@ func Test_Server_ListenAndServe(t *testing.T) {
 			wgListenAndServe.Add(1)
 			go func() {
 				defer wgListenAndServe.Done()
-				assert.Error(t, srv.ListenAndServe(p, mc, mr, transferChan))
+				assert.Error(t, srv.ListenAndServe(mc, mr, transferChan))
 			}()
 
 			runtime.Gosched()
 
-			gc, err := tt.buildClientFn(host, port)
+			gc, err := tt.buildClientFn(tt.name, addr)
 			require.NoError(t, err)
 			require.NotNil(t, gc)
 			err = gc.SendMetric(client.Metric{
@@ -102,3 +89,30 @@ func Test_Server_ListenAndServe(t *testing.T) {
 		})
 	}
 }
+
+func testFreeEndpoint(t *testing.T, transport string, address string) {
+	t.Helper()
+
+	var ln0, ln1 io.Closer
+	var err0, err1 error
+
+	trans, err := NewTransport(transport)
+	require.NoError(t, err)
+
+	if trans.IsPacketTransport() {
+		// Endpoint should be free.
+		ln0, err0 = net.ListenPacket(transport, address)
+		ln1, err1 = net.ListenPacket(transport, address)
+	}
+
+	// Endpoint should be free.
+	require.NoError(t, err0)
+	require.NotNil(t, ln0)
+
+	// Ensure that the endpoint wasn't something like ":0" by checking that a second listener will fail.
+	require.Error(t, err1)
+	require.Nil(t, ln1)
+
+	// Unbind the local address so the mock UDP service can use it
+	require.NoError(t, ln0.Close())
+}
diff --git a/receiver/statsdreceiver/internal/transport/transport.go b/receiver/statsdreceiver/internal/transport/transport.go
new file mode 100644
index 000000000000..39eee2fa4e6d
--- /dev/null
+++ b/receiver/statsdreceiver/internal/transport/transport.go
@@ -0,0 +1,45 @@
+package transport // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport"
+
+import "errors"
+
+// Transport is a set of constants of the transport supported by this receiver.
+type Transport string
+
+var (
+	ErrUnsupportedTransport       = errors.New("unsupported transport")
+	ErrUnsupportedPacketTransport = errors.New("unsupported Packet transport")
+)
+
+const (
+	UDP  Transport = "udp"
+	UDP4 Transport = "udp4"
+	UDP6 Transport = "udp6"
+)
+
+// Create a Transport based on the transport string or return error if it is not supported.
+func NewTransport(ts string) (Transport, error) {
+	trans := Transport(ts)
+	switch trans {
+	case UDP, UDP4, UDP6:
+		return trans, nil
+	}
+	return Transport(""), ErrUnsupportedTransport
+}
+
+// Returns the string of this transport.
+func (trans Transport) String() string {
+	switch trans {
+	case UDP, UDP4, UDP6:
+		return string(trans)
+	}
+	return ""
+}
+
+// Returns true if the transport us packet based.
+func (trans Transport) IsPacketTransport() bool {
+	switch trans {
+	case UDP, UDP4, UDP6:
+		return true
+	}
+	return false
+}
diff --git a/receiver/statsdreceiver/internal/transport/udp_server.go b/receiver/statsdreceiver/internal/transport/udp_server.go
index 7a483ce61649..7245ac2aa564 100644
--- a/receiver/statsdreceiver/internal/transport/udp_server.go
+++ b/receiver/statsdreceiver/internal/transport/udp_server.go
@@ -6,47 +6,50 @@ package transport // import "github.com/open-telemetry/opentelemetry-collector-c
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"io"
 	"net"
 	"strings"
 
 	"go.opentelemetry.io/collector/consumer"
-
-	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/protocol"
 )
 
 type udpServer struct {
 	packetConn net.PacketConn
-	reporter   Reporter
+	transport  Transport
 }
 
+// Ensure that Server is implemented on UDP Server.
 var _ (Server) = (*udpServer)(nil)
 
 // NewUDPServer creates a transport.Server using UDP as its transport.
-func NewUDPServer(addr string) (Server, error) {
-	packetConn, err := net.ListenPacket("udp", addr)
-	if err != nil {
-		return nil, err
+func NewUDPServer(transport Transport, address string) (Server, error) {
+	var usrv udpServer
+	var err error
+
+	if !transport.IsPacketTransport() {
+		return nil, ErrUnsupportedPacketTransport
 	}
 
-	u := udpServer{
-		packetConn: packetConn,
+	usrv.transport = transport
+	usrv.packetConn, err = net.ListenPacket(transport.String(), address)
+	if err != nil {
+		return nil, fmt.Errorf("starting to listen %s socket: %w", transport.String(), err)
 	}
-	return &u, nil
+
+	return &usrv, nil
 }
 
+// Start the server ready to recevie metrics.
 func (u *udpServer) ListenAndServe(
-	parser protocol.Parser,
 	nextConsumer consumer.Metrics,
 	reporter Reporter,
 	transferChan chan<- Metric,
 ) error {
-	if parser == nil || nextConsumer == nil || reporter == nil {
+	if nextConsumer == nil || reporter == nil {
 		return errNilListenAndServeParameters
 	}
 
-	u.reporter = reporter
-
 	buf := make([]byte, 65527) // max size for udp packet body (assuming ipv6)
 	for {
 		n, addr, err := u.packetConn.ReadFrom(buf)
@@ -56,10 +59,8 @@ func (u *udpServer) ListenAndServe(
 			u.handlePacket(bufCopy, addr, transferChan)
 		}
 		if err != nil {
-			u.reporter.OnDebugf("UDP Transport (%s) - ReadFrom error: %v",
-				u.packetConn.LocalAddr(),
-				err)
 			var netErr net.Error
+			reporter.OnDebugf("%s Transport (%s) - ReadFrom error: %v", u.transport, u.packetConn.LocalAddr(), err)
 			if errors.As(err, &netErr) {
 				if netErr.Timeout() {
 					continue
@@ -70,10 +71,12 @@ func (u *udpServer) ListenAndServe(
 	}
 }
 
+// Closes the server
 func (u *udpServer) Close() error {
 	return u.packetConn.Close()
 }
 
+// This helper parses the buffer and split it line bye line to be parsed upstream.
 func (u *udpServer) handlePacket(
 	data []byte,
 	addr net.Addr,
diff --git a/receiver/statsdreceiver/receiver.go b/receiver/statsdreceiver/receiver.go
index feac277f7716..2602424da960 100644
--- a/receiver/statsdreceiver/receiver.go
+++ b/receiver/statsdreceiver/receiver.go
@@ -69,12 +69,13 @@ func New(
 
 func buildTransportServer(config Config) (transport.Server, error) {
 	// TODO: Add TCP/unix socket transport implementations
-	switch strings.ToLower(config.NetAddr.Transport) {
-	case "", "udp":
-		return transport.NewUDPServer(config.NetAddr.Endpoint)
+	trans, err := transport.NewTransport(strings.ToLower(config.NetAddr.Transport))
+	switch trans {
+	case transport.UDP, transport.UDP4, transport.UDP6:
+		return transport.NewUDPServer(trans, config.NetAddr.Endpoint)
 	}
 
-	return nil, fmt.Errorf("unsupported transport %q", config.NetAddr.Transport)
+	return nil, fmt.Errorf("error building server with transport %q: %w", config.NetAddr.Transport, err)
 }
 
 // Start starts a UDP server that can process StatsD messages.
@@ -96,7 +97,7 @@ func (r *statsdReceiver) Start(ctx context.Context, host component.Host) error {
 		return err
 	}
 	go func() {
-		if err := r.server.ListenAndServe(r.parser, r.nextConsumer, r.reporter, transferChan); err != nil {
+		if err := r.server.ListenAndServe(r.nextConsumer, r.reporter, transferChan); err != nil {
 			if !errors.Is(err, net.ErrClosed) {
 				host.ReportFatalError(err)
 			}
diff --git a/receiver/statsdreceiver/receiver_test.go b/receiver/statsdreceiver/receiver_test.go
index 2332740adb72..ae4e0e47efe6 100644
--- a/receiver/statsdreceiver/receiver_test.go
+++ b/receiver/statsdreceiver/receiver_test.go
@@ -6,8 +6,6 @@ package statsdreceiver
 import (
 	"context"
 	"errors"
-	"net"
-	"strconv"
 	"testing"
 	"time"
 
@@ -74,7 +72,7 @@ func Test_statsdreceiver_Start(t *testing.T) {
 				},
 				nextConsumer: consumertest.NewNop(),
 			},
-			wantErr: errors.New("unsupported transport \"unknown\""),
+			wantErr: errors.New("error building server with transport \"unknown\": unsupported transport"),
 		},
 	}
 	for _, tt := range tests {
@@ -82,7 +80,7 @@ func Test_statsdreceiver_Start(t *testing.T) {
 			receiver, err := New(receivertest.NewNopCreateSettings(), tt.args.config, tt.args.nextConsumer)
 			require.NoError(t, err)
 			err = receiver.Start(context.Background(), componenttest.NewNopHost())
-			assert.Equal(t, tt.wantErr, err)
+			assert.Equal(t, tt.wantErr.Error(), err.Error())
 
 			assert.NoError(t, receiver.Shutdown(context.Background()))
 		})
@@ -113,19 +111,16 @@ func TestStatsdReceiver_Flush(t *testing.T) {
 }
 
 func Test_statsdreceiver_EndToEnd(t *testing.T) {
-	addr := testutil.GetAvailableLocalAddress(t)
-	host, portStr, err := net.SplitHostPort(addr)
-	require.NoError(t, err)
-	port, err := strconv.Atoi(portStr)
-	require.NoError(t, err)
-
 	tests := []struct {
 		name     string
+		addr     string
 		configFn func() *Config
-		clientFn func(t *testing.T) *client.StatsD
+		clientFn func(t *testing.T, addr string) *client.StatsD
+		testSkip bool
 	}{
 		{
 			name: "default_config with 4s interval",
+			addr: testutil.GetAvailableLocalNetworkAddress(t, "udp"),
 			configFn: func() *Config {
 				return &Config{
 					NetAddr: confignet.NetAddr{
@@ -135,17 +130,21 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 					AggregationInterval: 4 * time.Second,
 				}
 			},
-			clientFn: func(t *testing.T) *client.StatsD {
-				c, err := client.NewStatsD(client.UDP, host, port)
+			clientFn: func(t *testing.T, addr string) *client.StatsD {
+				c, err := client.NewStatsD("udp", addr)
 				require.NoError(t, err)
 				return c
 			},
 		},
 	}
 	for _, tt := range tests {
+		if tt.testSkip {
+			continue
+		}
+
 		t.Run(tt.name, func(t *testing.T) {
 			cfg := tt.configFn()
-			cfg.NetAddr.Endpoint = addr
+			cfg.NetAddr.Endpoint = tt.addr
 			sink := new(consumertest.MetricsSink)
 			rcv, err := New(receivertest.NewNopCreateSettings(), *cfg, sink)
 			require.NoError(t, err)
@@ -159,7 +158,7 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 				assert.NoError(t, r.Shutdown(context.Background()))
 			}()
 
-			statsdClient := tt.clientFn(t)
+			statsdClient := tt.clientFn(t, tt.addr)
 
 			statsdMetric := client.Metric{
 				Name:  "test.metric",

From 448cdb05f07b92de2aa0f40c61232c572bb37174 Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 10:34:57 +0200
Subject: [PATCH 02/17] address christian comments

---
 .../internal/transport/server_test.go               |  4 ++--
 .../statsdreceiver/internal/transport/transport.go  | 13 +++----------
 .../statsdreceiver/internal/transport/udp_server.go | 13 ++++++++++---
 receiver/statsdreceiver/receiver.go                 |  7 +++----
 receiver/statsdreceiver/receiver_test.go            |  9 ++-------
 5 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/receiver/statsdreceiver/internal/transport/server_test.go b/receiver/statsdreceiver/internal/transport/server_test.go
index 55b549e31a25..8734feac6858 100644
--- a/receiver/statsdreceiver/internal/transport/server_test.go
+++ b/receiver/statsdreceiver/internal/transport/server_test.go
@@ -96,8 +96,8 @@ func testFreeEndpoint(t *testing.T, transport string, address string) {
 	var ln0, ln1 io.Closer
 	var err0, err1 error
 
-	trans, err := NewTransport(transport)
-	require.NoError(t, err)
+	trans := NewTransport(transport)
+	require.NotEqual(t, trans, Transport(""))
 
 	if trans.IsPacketTransport() {
 		// Endpoint should be free.
diff --git a/receiver/statsdreceiver/internal/transport/transport.go b/receiver/statsdreceiver/internal/transport/transport.go
index 39eee2fa4e6d..849ec456d7ac 100644
--- a/receiver/statsdreceiver/internal/transport/transport.go
+++ b/receiver/statsdreceiver/internal/transport/transport.go
@@ -1,15 +1,8 @@
 package transport // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport"
 
-import "errors"
-
 // Transport is a set of constants of the transport supported by this receiver.
 type Transport string
 
-var (
-	ErrUnsupportedTransport       = errors.New("unsupported transport")
-	ErrUnsupportedPacketTransport = errors.New("unsupported Packet transport")
-)
-
 const (
 	UDP  Transport = "udp"
 	UDP4 Transport = "udp4"
@@ -17,13 +10,13 @@ const (
 )
 
 // Create a Transport based on the transport string or return error if it is not supported.
-func NewTransport(ts string) (Transport, error) {
+func NewTransport(ts string) Transport {
 	trans := Transport(ts)
 	switch trans {
 	case UDP, UDP4, UDP6:
-		return trans, nil
+		return trans
 	}
-	return Transport(""), ErrUnsupportedTransport
+	return Transport("")
 }
 
 // Returns the string of this transport.
diff --git a/receiver/statsdreceiver/internal/transport/udp_server.go b/receiver/statsdreceiver/internal/transport/udp_server.go
index 7245ac2aa564..0f2014e7ec72 100644
--- a/receiver/statsdreceiver/internal/transport/udp_server.go
+++ b/receiver/statsdreceiver/internal/transport/udp_server.go
@@ -19,8 +19,12 @@ type udpServer struct {
 	transport  Transport
 }
 
-// Ensure that Server is implemented on UDP Server.
-var _ (Server) = (*udpServer)(nil)
+var (
+	// Ensure that Server is implemented on UDP Server.
+	_ (Server) = (*udpServer)(nil)
+
+	ErrUnsupportedPacketTransport = errors.New("unsupported Packet transport")
+)
 
 // NewUDPServer creates a transport.Server using UDP as its transport.
 func NewUDPServer(transport Transport, address string) (Server, error) {
@@ -59,8 +63,11 @@ func (u *udpServer) ListenAndServe(
 			u.handlePacket(bufCopy, addr, transferChan)
 		}
 		if err != nil {
+			reporter.OnDebugf("%s Transport (%s) - ReadFrom error: %v",
+				u.transport,
+				u.packetConn.LocalAddr(),
+				err)
 			var netErr net.Error
-			reporter.OnDebugf("%s Transport (%s) - ReadFrom error: %v", u.transport, u.packetConn.LocalAddr(), err)
 			if errors.As(err, &netErr) {
 				if netErr.Timeout() {
 					continue
diff --git a/receiver/statsdreceiver/receiver.go b/receiver/statsdreceiver/receiver.go
index 2602424da960..ffef4396623c 100644
--- a/receiver/statsdreceiver/receiver.go
+++ b/receiver/statsdreceiver/receiver.go
@@ -68,14 +68,13 @@ func New(
 }
 
 func buildTransportServer(config Config) (transport.Server, error) {
+	trans := transport.NewTransport(strings.ToLower(config.NetAddr.Transport))
 	// TODO: Add TCP/unix socket transport implementations
-	trans, err := transport.NewTransport(strings.ToLower(config.NetAddr.Transport))
-	switch trans {
-	case transport.UDP, transport.UDP4, transport.UDP6:
+	if trans.IsPacketTransport() {
 		return transport.NewUDPServer(trans, config.NetAddr.Endpoint)
 	}
 
-	return nil, fmt.Errorf("error building server with transport %q: %w", config.NetAddr.Transport, err)
+	return nil, fmt.Errorf("unsupported transport %q", config.NetAddr.Transport)
 }
 
 // Start starts a UDP server that can process StatsD messages.
diff --git a/receiver/statsdreceiver/receiver_test.go b/receiver/statsdreceiver/receiver_test.go
index ae4e0e47efe6..1c034bf5a858 100644
--- a/receiver/statsdreceiver/receiver_test.go
+++ b/receiver/statsdreceiver/receiver_test.go
@@ -72,7 +72,7 @@ func Test_statsdreceiver_Start(t *testing.T) {
 				},
 				nextConsumer: consumertest.NewNop(),
 			},
-			wantErr: errors.New("error building server with transport \"unknown\": unsupported transport"),
+			wantErr: errors.New("unsupported transport \"unknown\""),
 		},
 	}
 	for _, tt := range tests {
@@ -80,7 +80,7 @@ func Test_statsdreceiver_Start(t *testing.T) {
 			receiver, err := New(receivertest.NewNopCreateSettings(), tt.args.config, tt.args.nextConsumer)
 			require.NoError(t, err)
 			err = receiver.Start(context.Background(), componenttest.NewNopHost())
-			assert.Equal(t, tt.wantErr.Error(), err.Error())
+			assert.Equal(t, tt.wantErr, err)
 
 			assert.NoError(t, receiver.Shutdown(context.Background()))
 		})
@@ -116,7 +116,6 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 		addr     string
 		configFn func() *Config
 		clientFn func(t *testing.T, addr string) *client.StatsD
-		testSkip bool
 	}{
 		{
 			name: "default_config with 4s interval",
@@ -138,10 +137,6 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 		},
 	}
 	for _, tt := range tests {
-		if tt.testSkip {
-			continue
-		}
-
 		t.Run(tt.name, func(t *testing.T) {
 			cfg := tt.configFn()
 			cfg.NetAddr.Endpoint = tt.addr

From 42833bbd2b62bd8085c14064d144a8e5037a959e Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 10:41:30 +0200
Subject: [PATCH 03/17] address marc comments

---
 receiver/statsdreceiver/internal/transport/transport.go  | 6 +++---
 receiver/statsdreceiver/internal/transport/udp_server.go | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/receiver/statsdreceiver/internal/transport/transport.go b/receiver/statsdreceiver/internal/transport/transport.go
index 849ec456d7ac..87593f397e34 100644
--- a/receiver/statsdreceiver/internal/transport/transport.go
+++ b/receiver/statsdreceiver/internal/transport/transport.go
@@ -9,7 +9,7 @@ const (
 	UDP6 Transport = "udp6"
 )
 
-// Create a Transport based on the transport string or return error if it is not supported.
+// NewTransport creates a Transport based on the transport string or returns an empty Transport.
 func NewTransport(ts string) Transport {
 	trans := Transport(ts)
 	switch trans {
@@ -19,7 +19,7 @@ func NewTransport(ts string) Transport {
 	return Transport("")
 }
 
-// Returns the string of this transport.
+// String casts the transport to a String if the Transport is supported. Return an empty Transport overwise.
 func (trans Transport) String() string {
 	switch trans {
 	case UDP, UDP4, UDP6:
@@ -28,7 +28,7 @@ func (trans Transport) String() string {
 	return ""
 }
 
-// Returns true if the transport us packet based.
+// IsPacketTransport returns true if the transport is packet based.
 func (trans Transport) IsPacketTransport() bool {
 	switch trans {
 	case UDP, UDP4, UDP6:
diff --git a/receiver/statsdreceiver/internal/transport/udp_server.go b/receiver/statsdreceiver/internal/transport/udp_server.go
index 0f2014e7ec72..72abca77ce9c 100644
--- a/receiver/statsdreceiver/internal/transport/udp_server.go
+++ b/receiver/statsdreceiver/internal/transport/udp_server.go
@@ -44,7 +44,7 @@ func NewUDPServer(transport Transport, address string) (Server, error) {
 	return &usrv, nil
 }
 
-// Start the server ready to recevie metrics.
+// ListenAndServe starts the server ready to receive metrics.
 func (u *udpServer) ListenAndServe(
 	nextConsumer consumer.Metrics,
 	reporter Reporter,
@@ -78,12 +78,12 @@ func (u *udpServer) ListenAndServe(
 	}
 }
 
-// Closes the server
+// Close closes the server.
 func (u *udpServer) Close() error {
 	return u.packetConn.Close()
 }
 
-// This helper parses the buffer and split it line bye line to be parsed upstream.
+// handlePacket is helper that parses the buffer and split it line by line to be parsed upstream.
 func (u *udpServer) handlePacket(
 	data []byte,
 	addr net.Addr,

From d13cb5f7a1ada0793bc38178a7b61f7c3df36e31 Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 10:53:49 +0200
Subject: [PATCH 04/17] address paolo comments

---
 .../internal/transport/client/client.go          | 16 ++++++++--------
 .../internal/transport/udp_server.go             | 11 +++++------
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/receiver/statsdreceiver/internal/transport/client/client.go b/receiver/statsdreceiver/internal/transport/client/client.go
index 3e0121586e78..4ef4189a9f64 100644
--- a/receiver/statsdreceiver/internal/transport/client/client.go
+++ b/receiver/statsdreceiver/internal/transport/client/client.go
@@ -14,7 +14,7 @@ import (
 type StatsD struct {
 	transport string
 	address   string
-	Conn      io.Writer
+	conn      io.Writer
 }
 
 // NewStatsD creates a new StatsD instance to support the need for testing
@@ -33,7 +33,7 @@ func NewStatsD(transport string, address string) (*StatsD, error) {
 	return statsd, nil
 }
 
-// connect populates the StatsD.Conn
+// connect populates the StatsD.conn
 func (s *StatsD) connect() error {
 	switch s.transport {
 	case "udp":
@@ -41,7 +41,7 @@ func (s *StatsD) connect() error {
 		if err != nil {
 			return err
 		}
-		s.Conn, err = net.DialUDP(s.transport, nil, udpAddr)
+		s.conn, err = net.DialUDP(s.transport, nil, udpAddr)
 		if err != nil {
 			return err
 		}
@@ -52,20 +52,20 @@ func (s *StatsD) connect() error {
 	return nil
 }
 
-// Disconnect closes the StatsD.Conn.
+// Disconnect closes the StatsD.conn.
 func (s *StatsD) Disconnect() error {
 	var err error
-	if cl, ok := s.Conn.(io.Closer); ok {
+	if cl, ok := s.conn.(io.Closer); ok {
 		err = cl.Close()
 	}
-	s.Conn = nil
+	s.conn = nil
 	return err
 }
 
 // SendMetric sends the input metric to the StatsD connection.
 func (s *StatsD) SendMetric(metric Metric) error {
-	_, err := io.Copy(s.Conn, strings.NewReader(metric.String()))
-	return err
+	_, err := io.Copy(s.conn, strings.NewReader(metric.String()))
+	return fmt.Errorf("send metric on test client: %w", err)
 }
 
 // Metric contains the metric fields for a StatsD message.
diff --git a/receiver/statsdreceiver/internal/transport/udp_server.go b/receiver/statsdreceiver/internal/transport/udp_server.go
index 72abca77ce9c..bc29d32dc997 100644
--- a/receiver/statsdreceiver/internal/transport/udp_server.go
+++ b/receiver/statsdreceiver/internal/transport/udp_server.go
@@ -28,20 +28,19 @@ var (
 
 // NewUDPServer creates a transport.Server using UDP as its transport.
 func NewUDPServer(transport Transport, address string) (Server, error) {
-	var usrv udpServer
-	var err error
-
 	if !transport.IsPacketTransport() {
 		return nil, ErrUnsupportedPacketTransport
 	}
 
-	usrv.transport = transport
-	usrv.packetConn, err = net.ListenPacket(transport.String(), address)
+	conn, err := net.ListenPacket(transport.String(), address)
 	if err != nil {
 		return nil, fmt.Errorf("starting to listen %s socket: %w", transport.String(), err)
 	}
 
-	return &usrv, nil
+	return &udpServer{
+		packetConn: conn,
+		transport:  transport,
+	}, nil
 }
 
 // ListenAndServe starts the server ready to receive metrics.

From 3af53095400905bb1ba6280f02ef5da1da8db57c Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 11:09:47 +0200
Subject: [PATCH 05/17] add changelog

---
 ...ceiver_statsdreceiver_add-uds-support.yaml | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100755 .chloggen/receiver_statsdreceiver_add-uds-support.yaml

diff --git a/.chloggen/receiver_statsdreceiver_add-uds-support.yaml b/.chloggen/receiver_statsdreceiver_add-uds-support.yaml
new file mode 100755
index 000000000000..ef1c79e17d57
--- /dev/null
+++ b/.chloggen/receiver_statsdreceiver_add-uds-support.yaml
@@ -0,0 +1,21 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: "bug_fix"
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: receiver/statsd
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: refactor of hardcoded tests for UDP Transport
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues:
+  - 21385
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

From 1bf88d01cc593021ba627b436a39def5da49da0e Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 11:13:01 +0200
Subject: [PATCH 06/17] remove leftovers

---
 receiver/statsdreceiver/config_test.go | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/receiver/statsdreceiver/config_test.go b/receiver/statsdreceiver/config_test.go
index eefcda88b485..8c4f17e09951 100644
--- a/receiver/statsdreceiver/config_test.go
+++ b/receiver/statsdreceiver/config_test.go
@@ -82,12 +82,11 @@ func TestValidate(t *testing.T) {
 	}
 
 	const (
-		negativeAggregationIntervalErr      = "aggregation_interval must be a positive duration"
-		noObjectNameErr                     = "must specify object id for all TimerHistogramMappings"
-		statsdTypeNotSupportErr             = "statsd_type is not a supported mapping for histogram and timing metrics: %s"
-		observerTypeNotSupportErr           = "observer_type is not supported for histogram and timing metrics: %s"
-		invalidHistogramErr                 = "histogram configuration requires observer_type: histogram"
-		socketConfigurationWithUDSServerErr = "socket configuration is unsupported if the transport is not a unix domain socket"
+		negativeAggregationIntervalErr = "aggregation_interval must be a positive duration"
+		noObjectNameErr                = "must specify object id for all TimerHistogramMappings"
+		statsdTypeNotSupportErr        = "statsd_type is not a supported mapping for histogram and timing metrics: %s"
+		observerTypeNotSupportErr      = "observer_type is not supported for histogram and timing metrics: %s"
+		invalidHistogramErr            = "histogram configuration requires observer_type: histogram"
 	)
 
 	tests := []test{

From f1848f767c5f267b610439b06fdd5fe36be364fb Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 12:37:01 +0200
Subject: [PATCH 07/17] return err only if it is an error

---
 receiver/statsdreceiver/internal/transport/client/client.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/receiver/statsdreceiver/internal/transport/client/client.go b/receiver/statsdreceiver/internal/transport/client/client.go
index 4ef4189a9f64..3692b2406ac8 100644
--- a/receiver/statsdreceiver/internal/transport/client/client.go
+++ b/receiver/statsdreceiver/internal/transport/client/client.go
@@ -65,7 +65,10 @@ func (s *StatsD) Disconnect() error {
 // SendMetric sends the input metric to the StatsD connection.
 func (s *StatsD) SendMetric(metric Metric) error {
 	_, err := io.Copy(s.conn, strings.NewReader(metric.String()))
-	return fmt.Errorf("send metric on test client: %w", err)
+	if err != nil {
+		return fmt.Errorf("send metric on test client: %w", err)
+	}
+	return nil
 }
 
 // Metric contains the metric fields for a StatsD message.

From 33b1172a96e61bc4ba57df2c0a80381c76bfb5e7 Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 13:02:37 +0200
Subject: [PATCH 08/17] fix linter license

---
 receiver/statsdreceiver/internal/transport/transport.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/receiver/statsdreceiver/internal/transport/transport.go b/receiver/statsdreceiver/internal/transport/transport.go
index 87593f397e34..862e4d0666c5 100644
--- a/receiver/statsdreceiver/internal/transport/transport.go
+++ b/receiver/statsdreceiver/internal/transport/transport.go
@@ -1,3 +1,6 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
 package transport // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport"
 
 // Transport is a set of constants of the transport supported by this receiver.

From 013f14589d2f6fd79a78ce69c0d93f14147a79d7 Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 13:30:55 +0200
Subject: [PATCH 09/17] remove more leftovers

---
 receiver/statsdreceiver/internal/transport/server_test.go | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/receiver/statsdreceiver/internal/transport/server_test.go b/receiver/statsdreceiver/internal/transport/server_test.go
index 8734feac6858..6ca437d1ef3c 100644
--- a/receiver/statsdreceiver/internal/transport/server_test.go
+++ b/receiver/statsdreceiver/internal/transport/server_test.go
@@ -25,7 +25,6 @@ func Test_Server_ListenAndServe(t *testing.T) {
 		buildServerFn     func(transport Transport, addr string) (Server, error)
 		getFreeEndpointFn func(t testing.TB, transport string) string
 		buildClientFn     func(transport string, address string) (*client.StatsD, error)
-		testSkip          bool
 	}{
 		{
 			name:              "udp",
@@ -35,10 +34,6 @@ func Test_Server_ListenAndServe(t *testing.T) {
 		},
 	}
 	for _, tt := range tests {
-		if tt.testSkip {
-			continue
-		}
-
 		t.Run(tt.name, func(t *testing.T) {
 			trans := Transport(tt.name)
 			addr := tt.getFreeEndpointFn(t, tt.name)

From e4f823821934d81cffc2fbfdb7edfa3bdd6e25df Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Mon, 21 Aug 2023 12:52:01 +0200
Subject: [PATCH 10/17] remove changelog

---
 ...ceiver_statsdreceiver_add-uds-support.yaml | 21 -------------------
 1 file changed, 21 deletions(-)
 delete mode 100755 .chloggen/receiver_statsdreceiver_add-uds-support.yaml

diff --git a/.chloggen/receiver_statsdreceiver_add-uds-support.yaml b/.chloggen/receiver_statsdreceiver_add-uds-support.yaml
deleted file mode 100755
index ef1c79e17d57..000000000000
--- a/.chloggen/receiver_statsdreceiver_add-uds-support.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-# Use this changelog template to create an entry for release notes.
-# If your change doesn't affect end users, such as a test fix or a tooling change,
-# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
-
-# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
-change_type: "bug_fix"
-
-# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
-component: receiver/statsd
-
-# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
-note: refactor of hardcoded tests for UDP Transport
-
-# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
-issues:
-  - 21385
-
-# (Optional) One or more lines of additional information to render under the primary note.
-# These lines will be padded with 2 spaces and then inserted directly into the document.
-# Use pipe (|) for multiline entries.
-subtext:

From 01c8ed20439de6747f6af24f7e029c8e2ccbf3af Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Tue, 1 Aug 2023 15:25:20 +0200
Subject: [PATCH 11/17] change UDP server name to a generic one

---
 .../{udp_server.go => packet_server.go}       | 26 +++++++++----------
 1 file changed, 13 insertions(+), 13 deletions(-)
 rename receiver/statsdreceiver/internal/transport/{udp_server.go => packet_server.go} (75%)

diff --git a/receiver/statsdreceiver/internal/transport/udp_server.go b/receiver/statsdreceiver/internal/transport/packet_server.go
similarity index 75%
rename from receiver/statsdreceiver/internal/transport/udp_server.go
rename to receiver/statsdreceiver/internal/transport/packet_server.go
index bc29d32dc997..b5cc9b729a55 100644
--- a/receiver/statsdreceiver/internal/transport/udp_server.go
+++ b/receiver/statsdreceiver/internal/transport/packet_server.go
@@ -14,37 +14,37 @@ import (
 	"go.opentelemetry.io/collector/consumer"
 )
 
-type udpServer struct {
+type packetServer struct {
 	packetConn net.PacketConn
 	transport  Transport
 }
 
 var (
 	// Ensure that Server is implemented on UDP Server.
-	_ (Server) = (*udpServer)(nil)
+	_ (Server) = (*packetServer)(nil)
 
 	ErrUnsupportedPacketTransport = errors.New("unsupported Packet transport")
 )
 
-// NewUDPServer creates a transport.Server using UDP as its transport.
-func NewUDPServer(transport Transport, address string) (Server, error) {
+// NewPacketServer creates a transport.Server using transports based on packets.
+func NewPacketServer(transport Transport, address string) (Server, error) {
 	if !transport.IsPacketTransport() {
 		return nil, ErrUnsupportedPacketTransport
 	}
 
 	conn, err := net.ListenPacket(transport.String(), address)
 	if err != nil {
-		return nil, fmt.Errorf("starting to listen %s socket: %w", transport.String(), err)
+		return nil, fmt.Errorf("starting to listen %s: %w", transport.String(), err)
 	}
 
-	return &udpServer{
+	return &packetServer{
 		packetConn: conn,
 		transport:  transport,
 	}, nil
 }
 
 // ListenAndServe starts the server ready to receive metrics.
-func (u *udpServer) ListenAndServe(
+func (psrv *packetServer) ListenAndServe(
 	nextConsumer consumer.Metrics,
 	reporter Reporter,
 	transferChan chan<- Metric,
@@ -55,16 +55,16 @@ func (u *udpServer) ListenAndServe(
 
 	buf := make([]byte, 65527) // max size for udp packet body (assuming ipv6)
 	for {
-		n, addr, err := u.packetConn.ReadFrom(buf)
+		n, addr, err := psrv.packetConn.ReadFrom(buf)
 		if n > 0 {
 			bufCopy := make([]byte, n)
 			copy(bufCopy, buf)
-			u.handlePacket(bufCopy, addr, transferChan)
+			psrv.handlePacket(bufCopy, addr, transferChan)
 		}
 		if err != nil {
 			reporter.OnDebugf("%s Transport (%s) - ReadFrom error: %v",
-				u.transport,
-				u.packetConn.LocalAddr(),
+				psrv.transport,
+				psrv.packetConn.LocalAddr(),
 				err)
 			var netErr net.Error
 			if errors.As(err, &netErr) {
@@ -78,12 +78,12 @@ func (u *udpServer) ListenAndServe(
 }
 
 // Close closes the server.
-func (u *udpServer) Close() error {
+func (psrv *packetServer) Close() error {
 	return u.packetConn.Close()
 }
 
 // handlePacket is helper that parses the buffer and split it line by line to be parsed upstream.
-func (u *udpServer) handlePacket(
+func (psrv *packetServer) handlePacket(
 	data []byte,
 	addr net.Addr,
 	transferChan chan<- Metric,

From ed30a215b92f148ed16ea8d5f6326068c3cb2311 Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Tue, 1 Aug 2023 16:17:29 +0200
Subject: [PATCH 12/17] Add UDS support to the receiver

---
 .../internal/testutil/temporary_socket.go     | 13 +++++++
 .../internal/transport/client/client.go       |  9 +++++
 .../internal/transport/packet_server.go       | 35 ++++++++++++++++++-
 .../internal/transport/server_test.go         | 15 +++++++-
 .../internal/transport/transport.go           | 20 ++++++++---
 receiver/statsdreceiver/receiver.go           |  5 ++-
 receiver/statsdreceiver/receiver_test.go      | 20 +++++++++++
 7 files changed, 107 insertions(+), 10 deletions(-)
 create mode 100644 receiver/statsdreceiver/internal/testutil/temporary_socket.go

diff --git a/receiver/statsdreceiver/internal/testutil/temporary_socket.go b/receiver/statsdreceiver/internal/testutil/temporary_socket.go
new file mode 100644
index 000000000000..c19152719ce1
--- /dev/null
+++ b/receiver/statsdreceiver/internal/testutil/temporary_socket.go
@@ -0,0 +1,13 @@
+package testutil
+
+import (
+	"crypto/rand"
+	"fmt"
+	"testing"
+)
+
+func CreateTemporarySocket(t testing.TB, _ string) string {
+	b := make([]byte, 10)
+	rand.Read(b)
+	return fmt.Sprintf("%s/%s", t.TempDir(), fmt.Sprintf("%x", b))
+}
diff --git a/receiver/statsdreceiver/internal/transport/client/client.go b/receiver/statsdreceiver/internal/transport/client/client.go
index 3692b2406ac8..8b6e38ac44f2 100644
--- a/receiver/statsdreceiver/internal/transport/client/client.go
+++ b/receiver/statsdreceiver/internal/transport/client/client.go
@@ -45,6 +45,15 @@ func (s *StatsD) connect() error {
 		if err != nil {
 			return err
 		}
+	case "unixgram":
+		unixAddr, err := net.ResolveUnixAddr(s.transport, s.address)
+		if err != nil {
+			return err
+		}
+		s.Conn, err = net.DialUnix(s.transport, nil, unixAddr)
+		if err != nil {
+			return err
+		}
 	default:
 		return fmt.Errorf("unknown/unsupported transport: %s", s.transport)
 	}
diff --git a/receiver/statsdreceiver/internal/transport/packet_server.go b/receiver/statsdreceiver/internal/transport/packet_server.go
index b5cc9b729a55..dbfec422080f 100644
--- a/receiver/statsdreceiver/internal/transport/packet_server.go
+++ b/receiver/statsdreceiver/internal/transport/packet_server.go
@@ -9,14 +9,17 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"os"
 	"strings"
 
 	"go.opentelemetry.io/collector/consumer"
+	"go.uber.org/multierr"
 )
 
 type packetServer struct {
 	packetConn net.PacketConn
 	transport  Transport
+	address    string
 }
 
 var (
@@ -32,12 +35,20 @@ func NewPacketServer(transport Transport, address string) (Server, error) {
 		return nil, ErrUnsupportedPacketTransport
 	}
 
+	if transport.IsUnixTransport() {
+		err := os.Remove(address)
+		if err != nil && !errors.Is(err, os.ErrNotExist) {
+			return nil, fmt.Errorf("removing socket failed: %w", err)
+		}
+	}
+
 	conn, err := net.ListenPacket(transport.String(), address)
 	if err != nil {
 		return nil, fmt.Errorf("starting to listen %s: %w", transport.String(), err)
 	}
 
 	return &packetServer{
+		address:    address,
 		packetConn: conn,
 		transport:  transport,
 	}, nil
@@ -56,6 +67,14 @@ func (psrv *packetServer) ListenAndServe(
 	buf := make([]byte, 65527) // max size for udp packet body (assuming ipv6)
 	for {
 		n, addr, err := psrv.packetConn.ReadFrom(buf)
+
+		if _, ok := psrv.packetConn.(*net.UnixConn); ok && addr == nil {
+			addr = &net.UnixAddr{
+				Net:  "unixgram",
+				Name: "UDS",
+			}
+		}
+
 		if n > 0 {
 			bufCopy := make([]byte, n)
 			copy(bufCopy, buf)
@@ -79,7 +98,21 @@ func (psrv *packetServer) ListenAndServe(
 
 // Close closes the server.
 func (psrv *packetServer) Close() error {
-	return u.packetConn.Close()
+	var errs error
+
+	if psrv.transport.IsUnixTransport() {
+		err := os.Remove(psrv.address)
+		if err != nil && !errors.Is(err, os.ErrNotExist) {
+			errs = multierr.Append(errs, fmt.Errorf("removing socket failed: %w", err))
+		}
+	}
+
+	err := psrv.packetConn.Close()
+	if err != nil {
+		errs = multierr.Append(errs, err)
+	}
+
+	return errs
 }
 
 // handlePacket is helper that parses the buffer and split it line by line to be parsed upstream.
diff --git a/receiver/statsdreceiver/internal/transport/server_test.go b/receiver/statsdreceiver/internal/transport/server_test.go
index 6ca437d1ef3c..e28f28ce2678 100644
--- a/receiver/statsdreceiver/internal/transport/server_test.go
+++ b/receiver/statsdreceiver/internal/transport/server_test.go
@@ -16,6 +16,7 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumertest"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/common/testutil"
+	statsdtestutil "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/client"
 )
 
@@ -29,9 +30,16 @@ func Test_Server_ListenAndServe(t *testing.T) {
 		{
 			name:              "udp",
 			getFreeEndpointFn: testutil.GetAvailableLocalNetworkAddress,
-			buildServerFn:     NewUDPServer,
+			buildServerFn:     NewPacketServer,
 			buildClientFn:     client.NewStatsD,
 		},
+		{
+			name:              "unixgram",
+			getFreeEndpointFn: statsdtestutil.CreateTemporarySocket,
+			buildServerFn:     NewPacketServer,
+			buildClientFn:     client.NewStatsD,
+			testSkip:          runtime.GOOS != "linux",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -85,6 +93,7 @@ func Test_Server_ListenAndServe(t *testing.T) {
 	}
 }
 
+// Util to see that the port we are going to use for testing is deterministic and free for us.
 func testFreeEndpoint(t *testing.T, transport string, address string) {
 	t.Helper()
 
@@ -99,6 +108,10 @@ func testFreeEndpoint(t *testing.T, transport string, address string) {
 		ln0, err0 = net.ListenPacket(transport, address)
 		ln1, err1 = net.ListenPacket(transport, address)
 	}
+	if trans.IsUnixTransport() {
+		// unix sockets rely on tempfiles so they are always free
+		return
+	}
 
 	// Endpoint should be free.
 	require.NoError(t, err0)
diff --git a/receiver/statsdreceiver/internal/transport/transport.go b/receiver/statsdreceiver/internal/transport/transport.go
index 862e4d0666c5..9addfaa92d5e 100644
--- a/receiver/statsdreceiver/internal/transport/transport.go
+++ b/receiver/statsdreceiver/internal/transport/transport.go
@@ -7,16 +7,17 @@ package transport // import "github.com/open-telemetry/opentelemetry-collector-c
 type Transport string
 
 const (
-	UDP  Transport = "udp"
-	UDP4 Transport = "udp4"
-	UDP6 Transport = "udp6"
+	UDP      Transport = "udp"
+	UDP4     Transport = "udp4"
+	UDP6     Transport = "udp6"
+	UnixGram Transport = "unixgram"
 )
 
 // NewTransport creates a Transport based on the transport string or returns an empty Transport.
 func NewTransport(ts string) Transport {
 	trans := Transport(ts)
 	switch trans {
-	case UDP, UDP4, UDP6:
+	case UDP, UDP4, UDP6, UnixGram:
 		return trans
 	}
 	return Transport("")
@@ -25,7 +26,7 @@ func NewTransport(ts string) Transport {
 // String casts the transport to a String if the Transport is supported. Return an empty Transport overwise.
 func (trans Transport) String() string {
 	switch trans {
-	case UDP, UDP4, UDP6:
+	case UDP, UDP4, UDP6, UnixGram:
 		return string(trans)
 	}
 	return ""
@@ -39,3 +40,12 @@ func (trans Transport) IsPacketTransport() bool {
 	}
 	return false
 }
+
+// Returns true if the transport is unix socket based.
+func (trans Transport) IsUnixTransport() bool {
+	switch trans {
+	case UnixGram:
+		return true
+	}
+	return false
+}
diff --git a/receiver/statsdreceiver/receiver.go b/receiver/statsdreceiver/receiver.go
index ffef4396623c..073df3c98f46 100644
--- a/receiver/statsdreceiver/receiver.go
+++ b/receiver/statsdreceiver/receiver.go
@@ -68,12 +68,11 @@ func New(
 }
 
 func buildTransportServer(config Config) (transport.Server, error) {
+	// TODO: Add TCP transport implementation
 	trans := transport.NewTransport(strings.ToLower(config.NetAddr.Transport))
-	// TODO: Add TCP/unix socket transport implementations
 	if trans.IsPacketTransport() {
-		return transport.NewUDPServer(trans, config.NetAddr.Endpoint)
+		return transport.NewPacketServer(trans, config.NetAddr.Endpoint)
 	}
-
 	return nil, fmt.Errorf("unsupported transport %q", config.NetAddr.Transport)
 }
 
diff --git a/receiver/statsdreceiver/receiver_test.go b/receiver/statsdreceiver/receiver_test.go
index 1c034bf5a858..c62627d26b1b 100644
--- a/receiver/statsdreceiver/receiver_test.go
+++ b/receiver/statsdreceiver/receiver_test.go
@@ -6,6 +6,7 @@ package statsdreceiver
 import (
 	"context"
 	"errors"
+	"runtime"
 	"testing"
 	"time"
 
@@ -20,6 +21,7 @@ import (
 	"go.opentelemetry.io/collector/receiver/receivertest"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/common/testutil"
+	statsdtestutil "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/client"
 )
@@ -135,6 +137,24 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 				return c
 			},
 		},
+		{
+			name: "default_config with UDS listener (unixgram)",
+			addr: statsdtestutil.CreateTemporarySocket(t, ""),
+			configFn: func() *Config {
+				return &Config{
+					NetAddr: confignet.NetAddr{
+						Transport: "unixgram",
+					},
+					AggregationInterval: 4 * time.Second,
+				}
+			},
+			clientFn: func(t *testing.T, addr string) *client.StatsD {
+				c, err := client.NewStatsD("unixgram", addr)
+				require.NoError(t, err)
+				return c
+			},
+			testSkip: runtime.GOOS != "linux",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

From c7a82c12a712b3807cfceb1c9da883ea3c707c0e Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 13:34:11 +0200
Subject: [PATCH 13/17] fix rebase shenanigans

---
 .../statsdreceiver/internal/transport/client/client.go    | 2 +-
 receiver/statsdreceiver/internal/transport/server_test.go | 8 +++++++-
 receiver/statsdreceiver/receiver_test.go                  | 6 ++++++
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/receiver/statsdreceiver/internal/transport/client/client.go b/receiver/statsdreceiver/internal/transport/client/client.go
index 8b6e38ac44f2..fe4e009d2a2a 100644
--- a/receiver/statsdreceiver/internal/transport/client/client.go
+++ b/receiver/statsdreceiver/internal/transport/client/client.go
@@ -50,7 +50,7 @@ func (s *StatsD) connect() error {
 		if err != nil {
 			return err
 		}
-		s.Conn, err = net.DialUnix(s.transport, nil, unixAddr)
+		s.conn, err = net.DialUnix(s.transport, nil, unixAddr)
 		if err != nil {
 			return err
 		}
diff --git a/receiver/statsdreceiver/internal/transport/server_test.go b/receiver/statsdreceiver/internal/transport/server_test.go
index e28f28ce2678..3ea6ea47172a 100644
--- a/receiver/statsdreceiver/internal/transport/server_test.go
+++ b/receiver/statsdreceiver/internal/transport/server_test.go
@@ -26,6 +26,7 @@ func Test_Server_ListenAndServe(t *testing.T) {
 		buildServerFn     func(transport Transport, addr string) (Server, error)
 		getFreeEndpointFn func(t testing.TB, transport string) string
 		buildClientFn     func(transport string, address string) (*client.StatsD, error)
+		testSkip          bool
 	}{
 		{
 			name:              "udp",
@@ -38,10 +39,15 @@ func Test_Server_ListenAndServe(t *testing.T) {
 			getFreeEndpointFn: statsdtestutil.CreateTemporarySocket,
 			buildServerFn:     NewPacketServer,
 			buildClientFn:     client.NewStatsD,
-			testSkip:          runtime.GOOS != "linux",
+			// Tests on Mac/Windows give a "bind: invalid argument" error as unix sockets are not supported.
+			testSkip: runtime.GOOS != "linux",
 		},
 	}
 	for _, tt := range tests {
+		if tt.testSkip {
+			continue
+		}
+
 		t.Run(tt.name, func(t *testing.T) {
 			trans := Transport(tt.name)
 			addr := tt.getFreeEndpointFn(t, tt.name)
diff --git a/receiver/statsdreceiver/receiver_test.go b/receiver/statsdreceiver/receiver_test.go
index c62627d26b1b..ce301cc92514 100644
--- a/receiver/statsdreceiver/receiver_test.go
+++ b/receiver/statsdreceiver/receiver_test.go
@@ -118,6 +118,7 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 		addr     string
 		configFn func() *Config
 		clientFn func(t *testing.T, addr string) *client.StatsD
+		testSkip bool
 	}{
 		{
 			name: "default_config with 4s interval",
@@ -153,10 +154,15 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 				require.NoError(t, err)
 				return c
 			},
+			// Tests on Mac/Windows give a "bind: invalid argument" error as unix sockets are not supported.
 			testSkip: runtime.GOOS != "linux",
 		},
 	}
 	for _, tt := range tests {
+		if tt.testSkip {
+			continue
+		}
+
 		t.Run(tt.name, func(t *testing.T) {
 			cfg := tt.configFn()
 			cfg.NetAddr.Endpoint = tt.addr

From bfa94439a5a81a458ea1caffe051f6ec718dd2af Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 13:35:51 +0200
Subject: [PATCH 14/17] add changelog

---
 ...statsdreceiver_add-uds-support-part-2.yaml | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100755 .chloggen/receiver_statsdreceiver_add-uds-support-part-2.yaml

diff --git a/.chloggen/receiver_statsdreceiver_add-uds-support-part-2.yaml b/.chloggen/receiver_statsdreceiver_add-uds-support-part-2.yaml
new file mode 100755
index 000000000000..72d57d2fc47e
--- /dev/null
+++ b/.chloggen/receiver_statsdreceiver_add-uds-support-part-2.yaml
@@ -0,0 +1,21 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: "enhancement"
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: receiver/statsd
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add UDS support
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues:
+  - 21385
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
\ No newline at end of file

From ed1819b6c33ad423cf28fc5957947ca7838baba0 Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 13:47:55 +0200
Subject: [PATCH 15/17] refactor client to test util package

---
 .../{transport/client => testutil}/client.go  | 36 +++++++------------
 .../internal/testutil/metric.go               | 20 +++++++++++
 .../internal/testutil/temporary_socket.go     |  5 ++-
 .../internal/transport/server_test.go         |  9 +++--
 receiver/statsdreceiver/receiver_test.go      | 13 ++++---
 5 files changed, 46 insertions(+), 37 deletions(-)
 rename receiver/statsdreceiver/internal/{transport/client => testutil}/client.go (56%)
 create mode 100644 receiver/statsdreceiver/internal/testutil/metric.go

diff --git a/receiver/statsdreceiver/internal/transport/client/client.go b/receiver/statsdreceiver/internal/testutil/client.go
similarity index 56%
rename from receiver/statsdreceiver/internal/transport/client/client.go
rename to receiver/statsdreceiver/internal/testutil/client.go
index fe4e009d2a2a..165fa9596e88 100644
--- a/receiver/statsdreceiver/internal/transport/client/client.go
+++ b/receiver/statsdreceiver/internal/testutil/client.go
@@ -1,7 +1,7 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
-package client // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/client"
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/testutil"
 
 import (
 	"fmt"
@@ -10,17 +10,17 @@ import (
 	"strings"
 )
 
-// StatsD defines the properties of a StatsD connection.
-type StatsD struct {
+// StatsDTestClient defines the properties of a StatsD connection.
+type StatsDTestClient struct {
 	transport string
 	address   string
 	conn      io.Writer
 }
 
-// NewStatsD creates a new StatsD instance to support the need for testing
+// NewStatsDTestClient creates a new StatsDTestClient instance to support the need for testing
 // the statsdreceiver package and is not intended/tested to be used in production.
-func NewStatsD(transport string, address string) (*StatsD, error) {
-	statsd := &StatsD{
+func NewStatsDTestClient(transport string, address string) (*StatsDTestClient, error) {
+	statsd := &StatsDTestClient{
 		transport: transport,
 		address:   address,
 	}
@@ -33,8 +33,8 @@ func NewStatsD(transport string, address string) (*StatsD, error) {
 	return statsd, nil
 }
 
-// connect populates the StatsD.conn
-func (s *StatsD) connect() error {
+// connect populates the StatsDTestClient.conn
+func (s *StatsDTestClient) connect() error {
 	switch s.transport {
 	case "udp":
 		udpAddr, err := net.ResolveUDPAddr(s.transport, s.address)
@@ -61,8 +61,8 @@ func (s *StatsD) connect() error {
 	return nil
 }
 
-// Disconnect closes the StatsD.conn.
-func (s *StatsD) Disconnect() error {
+// Disconnect closes the StatsDTestClient.conn.
+func (s *StatsDTestClient) Disconnect() error {
 	var err error
 	if cl, ok := s.conn.(io.Closer); ok {
 		err = cl.Close()
@@ -71,23 +71,11 @@ func (s *StatsD) Disconnect() error {
 	return err
 }
 
-// SendMetric sends the input metric to the StatsD connection.
-func (s *StatsD) SendMetric(metric Metric) error {
+// SendMetric sends the input metric to the StatsDTestClient connection.
+func (s *StatsDTestClient) SendMetric(metric Metric) error {
 	_, err := io.Copy(s.conn, strings.NewReader(metric.String()))
 	if err != nil {
 		return fmt.Errorf("send metric on test client: %w", err)
 	}
 	return nil
 }
-
-// Metric contains the metric fields for a StatsD message.
-type Metric struct {
-	Name  string
-	Value string
-	Type  string
-}
-
-// String formats a Metric into a StatsD message.
-func (m Metric) String() string {
-	return fmt.Sprintf("%s:%s|%s", m.Name, m.Value, m.Type)
-}
diff --git a/receiver/statsdreceiver/internal/testutil/metric.go b/receiver/statsdreceiver/internal/testutil/metric.go
new file mode 100644
index 000000000000..4d648a42fe26
--- /dev/null
+++ b/receiver/statsdreceiver/internal/testutil/metric.go
@@ -0,0 +1,20 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/testutil"
+
+import (
+	"fmt"
+)
+
+// Metric contains the metric fields for a StatsDTestClient message.
+type Metric struct {
+	Name  string
+	Value string
+	Type  string
+}
+
+// String formats a Metric into a StatsDTestClient message.
+func (m Metric) String() string {
+	return fmt.Sprintf("%s:%s|%s", m.Name, m.Value, m.Type)
+}
diff --git a/receiver/statsdreceiver/internal/testutil/temporary_socket.go b/receiver/statsdreceiver/internal/testutil/temporary_socket.go
index c19152719ce1..e1e657e9db00 100644
--- a/receiver/statsdreceiver/internal/testutil/temporary_socket.go
+++ b/receiver/statsdreceiver/internal/testutil/temporary_socket.go
@@ -1,4 +1,7 @@
-package testutil
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/transport/testutil"
 
 import (
 	"crypto/rand"
diff --git a/receiver/statsdreceiver/internal/transport/server_test.go b/receiver/statsdreceiver/internal/transport/server_test.go
index 3ea6ea47172a..2c175fb8d71f 100644
--- a/receiver/statsdreceiver/internal/transport/server_test.go
+++ b/receiver/statsdreceiver/internal/transport/server_test.go
@@ -17,7 +17,6 @@ import (
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/common/testutil"
 	statsdtestutil "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
-	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/client"
 )
 
 func Test_Server_ListenAndServe(t *testing.T) {
@@ -25,20 +24,20 @@ func Test_Server_ListenAndServe(t *testing.T) {
 		name              string
 		buildServerFn     func(transport Transport, addr string) (Server, error)
 		getFreeEndpointFn func(t testing.TB, transport string) string
-		buildClientFn     func(transport string, address string) (*client.StatsD, error)
+		buildClientFn     func(transport string, address string) (*statsdtestutil.StatsDTestClient, error)
 		testSkip          bool
 	}{
 		{
 			name:              "udp",
 			getFreeEndpointFn: testutil.GetAvailableLocalNetworkAddress,
 			buildServerFn:     NewPacketServer,
-			buildClientFn:     client.NewStatsD,
+			buildClientFn:     statsdtestutil.NewStatsDTestClient,
 		},
 		{
 			name:              "unixgram",
 			getFreeEndpointFn: statsdtestutil.CreateTemporarySocket,
 			buildServerFn:     NewPacketServer,
-			buildClientFn:     client.NewStatsD,
+			buildClientFn:     statsdtestutil.NewStatsDTestClient,
 			// Tests on Mac/Windows give a "bind: invalid argument" error as unix sockets are not supported.
 			testSkip: runtime.GOOS != "linux",
 		},
@@ -74,7 +73,7 @@ func Test_Server_ListenAndServe(t *testing.T) {
 			gc, err := tt.buildClientFn(tt.name, addr)
 			require.NoError(t, err)
 			require.NotNil(t, gc)
-			err = gc.SendMetric(client.Metric{
+			err = gc.SendMetric(statsdtestutil.Metric{
 				Name:  "test.metric",
 				Value: "42",
 				Type:  "c",
diff --git a/receiver/statsdreceiver/receiver_test.go b/receiver/statsdreceiver/receiver_test.go
index ce301cc92514..3ae7a19dda5e 100644
--- a/receiver/statsdreceiver/receiver_test.go
+++ b/receiver/statsdreceiver/receiver_test.go
@@ -23,7 +23,6 @@ import (
 	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/common/testutil"
 	statsdtestutil "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport"
-	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/client"
 )
 
 func Test_statsdreceiver_New(t *testing.T) {
@@ -117,7 +116,7 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 		name     string
 		addr     string
 		configFn func() *Config
-		clientFn func(t *testing.T, addr string) *client.StatsD
+		clientFn func(t *testing.T, addr string) *statsdtestutil.StatsDTestClient
 		testSkip bool
 	}{
 		{
@@ -132,8 +131,8 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 					AggregationInterval: 4 * time.Second,
 				}
 			},
-			clientFn: func(t *testing.T, addr string) *client.StatsD {
-				c, err := client.NewStatsD("udp", addr)
+			clientFn: func(t *testing.T, addr string) *statsdtestutil.StatsDTestClient {
+				c, err := statsdtestutil.NewStatsDTestClient("udp", addr)
 				require.NoError(t, err)
 				return c
 			},
@@ -149,8 +148,8 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 					AggregationInterval: 4 * time.Second,
 				}
 			},
-			clientFn: func(t *testing.T, addr string) *client.StatsD {
-				c, err := client.NewStatsD("unixgram", addr)
+			clientFn: func(t *testing.T, addr string) *statsdtestutil.StatsDTestClient {
+				c, err := statsdtestutil.NewStatsDTestClient("unixgram", addr)
 				require.NoError(t, err)
 				return c
 			},
@@ -181,7 +180,7 @@ func Test_statsdreceiver_EndToEnd(t *testing.T) {
 
 			statsdClient := tt.clientFn(t, tt.addr)
 
-			statsdMetric := client.Metric{
+			statsdMetric := statsdtestutil.Metric{
 				Name:  "test.metric",
 				Value: "42",
 				Type:  "c",

From beb01bf08ef8ae061d98c376e6e243fc3051372c Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 15:18:56 +0200
Subject: [PATCH 16/17] address internal comments

---
 .../statsdreceiver/internal/transport/packet_server.go |  2 +-
 .../statsdreceiver/internal/transport/server_test.go   | 10 +++++-----
 receiver/statsdreceiver/receiver.go                    |  2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/receiver/statsdreceiver/internal/transport/packet_server.go b/receiver/statsdreceiver/internal/transport/packet_server.go
index dbfec422080f..78f709c3d6ed 100644
--- a/receiver/statsdreceiver/internal/transport/packet_server.go
+++ b/receiver/statsdreceiver/internal/transport/packet_server.go
@@ -68,7 +68,7 @@ func (psrv *packetServer) ListenAndServe(
 	for {
 		n, addr, err := psrv.packetConn.ReadFrom(buf)
 
-		if _, ok := psrv.packetConn.(*net.UnixConn); ok && addr == nil {
+		if psrv.transport.IsUnixTransport() && addr == nil {
 			addr = &net.UnixAddr{
 				Net:  "unixgram",
 				Name: "UDS",
diff --git a/receiver/statsdreceiver/internal/transport/server_test.go b/receiver/statsdreceiver/internal/transport/server_test.go
index 2c175fb8d71f..1391e160bb4b 100644
--- a/receiver/statsdreceiver/internal/transport/server_test.go
+++ b/receiver/statsdreceiver/internal/transport/server_test.go
@@ -98,7 +98,7 @@ func Test_Server_ListenAndServe(t *testing.T) {
 	}
 }
 
-// Util to see that the port we are going to use for testing is deterministic and free for us.
+// testFreeEndpoint is a helper to check if the port we are going to use for testing is deterministic and free for us.
 func testFreeEndpoint(t *testing.T, transport string, address string) {
 	t.Helper()
 
@@ -108,15 +108,15 @@ func testFreeEndpoint(t *testing.T, transport string, address string) {
 	trans := NewTransport(transport)
 	require.NotEqual(t, trans, Transport(""))
 
+	if trans.IsUnixTransport() {
+		// unix sockets rely on tempfiles so they are always free
+		return
+	}
 	if trans.IsPacketTransport() {
 		// Endpoint should be free.
 		ln0, err0 = net.ListenPacket(transport, address)
 		ln1, err1 = net.ListenPacket(transport, address)
 	}
-	if trans.IsUnixTransport() {
-		// unix sockets rely on tempfiles so they are always free
-		return
-	}
 
 	// Endpoint should be free.
 	require.NoError(t, err0)
diff --git a/receiver/statsdreceiver/receiver.go b/receiver/statsdreceiver/receiver.go
index 073df3c98f46..960b9628d254 100644
--- a/receiver/statsdreceiver/receiver.go
+++ b/receiver/statsdreceiver/receiver.go
@@ -68,8 +68,8 @@ func New(
 }
 
 func buildTransportServer(config Config) (transport.Server, error) {
-	// TODO: Add TCP transport implementation
 	trans := transport.NewTransport(strings.ToLower(config.NetAddr.Transport))
+	// TODO: Add TCP transport implementation
 	if trans.IsPacketTransport() {
 		return transport.NewPacketServer(trans, config.NetAddr.Endpoint)
 	}

From 116da7b20fd0cd5cd749fc55f7db7865ca2ba73d Mon Sep 17 00:00:00 2001
From: Juan Manuel Perez <jperezflorez@newrelic.com>
Date: Thu, 3 Aug 2023 15:31:20 +0200
Subject: [PATCH 17/17] fix goporto imports

---
 receiver/statsdreceiver/internal/testutil/client.go           | 2 +-
 receiver/statsdreceiver/internal/testutil/metric.go           | 2 +-
 receiver/statsdreceiver/internal/testutil/temporary_socket.go | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/receiver/statsdreceiver/internal/testutil/client.go b/receiver/statsdreceiver/internal/testutil/client.go
index 165fa9596e88..0c3ec6126966 100644
--- a/receiver/statsdreceiver/internal/testutil/client.go
+++ b/receiver/statsdreceiver/internal/testutil/client.go
@@ -1,7 +1,7 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
-package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/testutil"
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
 
 import (
 	"fmt"
diff --git a/receiver/statsdreceiver/internal/testutil/metric.go b/receiver/statsdreceiver/internal/testutil/metric.go
index 4d648a42fe26..3ef3aff16829 100644
--- a/receiver/statsdreceiver/internal/testutil/metric.go
+++ b/receiver/statsdreceiver/internal/testutil/metric.go
@@ -1,7 +1,7 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
-package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/transport/testutil"
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
 
 import (
 	"fmt"
diff --git a/receiver/statsdreceiver/internal/testutil/temporary_socket.go b/receiver/statsdreceiver/internal/testutil/temporary_socket.go
index e1e657e9db00..5844a5b89919 100644
--- a/receiver/statsdreceiver/internal/testutil/temporary_socket.go
+++ b/receiver/statsdreceiver/internal/testutil/temporary_socket.go
@@ -1,7 +1,7 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
-package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/transport/testutil"
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
 
 import (
 	"crypto/rand"