Add UDS support

.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:

receiver/statsdreceiver/config_test.go

@@ -86,6 +86,7 @@ func TestValidate(t *testing.T) {
 		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{
@@ -153,7 +154,7 @@ func TestValidate(t *testing.T) {
 					},
 				},
 			},
-			expectedErr: "histogram configuration requires observer_type: histogram",
+			expectedErr: invalidHistogramErr,
 		},
 		{
 			name: "negativeAggregationInterval",
@@ -163,7 +164,7 @@ func TestValidate(t *testing.T) {
 					{StatsdType: "timing", ObserverType: "gauge"},
 				},
 			},
-			expectedErr: "aggregation_interval must be a positive duration",
+			expectedErr: negativeAggregationIntervalErr,
 		},
 	}
 

receiver/statsdreceiver/internal/testutil/client.go

@@ -0,0 +1,81 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/testutil"
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"strings"
+)
+
+// StatsDTestClient defines the properties of a StatsD connection.
+type StatsDTestClient struct {
+	transport string
+	address   string
+	conn      io.Writer
+}
+
+// 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 NewStatsDTestClient(transport string, address string) (*StatsDTestClient, error) {
+	statsd := &StatsDTestClient{
+		transport: transport,
+		address:   address,
+	}
+
+	err := statsd.connect()
+	if err != nil {
+		return nil, err
+	}
+
+	return statsd, nil
+}
+
+// connect populates the StatsDTestClient.conn
+func (s *StatsDTestClient) 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(s.transport, nil, udpAddr)
+		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)
+	}
+
+	return nil
+}
+
+// Disconnect closes the StatsDTestClient.conn.
+func (s *StatsDTestClient) Disconnect() error {
+	var err error
+	if cl, ok := s.conn.(io.Closer); ok {
+		err = cl.Close()
+	}
+	s.conn = nil
+	return err
+}
+
+// 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
+}

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/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)
+}

receiver/statsdreceiver/internal/testutil/temporary_socket.go

@@ -0,0 +1,16 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package testutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/statsdreceiver/internal/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))
+}