Test for issue open-telemetry#33300

The current syslog exporter does not handle structured data well.
In particular, when there is more than one structured data field,
it will put them all in one structured data block rather than in
one block per field as the RFC5424 suggests.

This test is a test for this error.

Author: peffis

exporter/syslogexporter/rfc5424_formatter_test.go

@@ -6,6 +6,7 @@ package syslogexporter
 import (
 	"fmt"
 	"regexp"
+	"strings"
 	"testing"
 	"time"
 
@@ -85,6 +86,47 @@ func TestRFC5424Formatter(t *testing.T) {
 	assert.Contains(t, actual, "UserID=\"Tester2\"")
 	assert.Contains(t, actual, "PEN=\"27389\"")
 
+	// Test structured data (more than one field)
+	expectedRegex = "\\<165\\>1 2003-08-24T12:14:15.000003Z 192\\.0\\.2\\.1 myproc 8710 - " +
+		"\\[\\S+ \\S+ \\S+\\]" +
+		"\\[\\S+ \\S+ \\S+\\]" +
+		" It's time to make the do-nuts\\.\n"
+	logRecord = plog.NewLogRecord()
+	logRecord.Attributes().PutStr("appname", "myproc")
+	logRecord.Attributes().PutStr("hostname", "192.0.2.1")
+	logRecord.Attributes().PutStr("message", "It's time to make the do-nuts.")
+	logRecord.Attributes().PutInt("priority", 165)
+	logRecord.Attributes().PutStr("proc_id", "8710")
+	logRecord.Attributes().PutEmptyMap("structured_data")
+	structuredData, found = logRecord.Attributes().Get("structured_data")
+	require.True(t, found)
+	structuredData.Map().PutEmptyMap("A@123")
+	structuredDataSubmap, found = structuredData.Map().Get("A@123")
+	require.True(t, found)
+	structuredDataSubmap.Map().PutStr("A", "123")
+	structuredDataSubmap.Map().PutStr("UserHostAddress", "192.168.2.132")
+	structuredData.Map().PutEmptyMap("B@321")
+	structuredDataSubmap, found = structuredData.Map().Get("B@321")
+	require.True(t, found)
+	structuredDataSubmap.Map().PutStr("B", "321")
+	structuredDataSubmap.Map().PutStr("UserHostAddress", "192.168.2.132")
+	logRecord.Attributes().PutInt("version", 1)
+
+	timestamp, err = time.Parse(time.RFC3339Nano, "2003-08-24T05:14:15.000003-07:00")
+	require.NoError(t, err)
+	logRecord.SetTimestamp(pcommon.NewTimestampFromTime(timestamp))
+
+	actual = newRFC5424Formatter(false).format(logRecord)
+	assert.NoError(t, err)
+	matched, err = regexp.MatchString(expectedRegex, actual)
+	assert.NoError(t, err)
+	assert.True(t, matched, fmt.Sprintf("unexpected form of formatted message, formatted message: %s, regexp: %s", actual, expectedRegex))
+	assert.True(t, strings.Contains(actual, "[A@123"))
+	assert.True(t, strings.Contains(actual, "A=\"123\""))
+	assert.True(t, strings.Contains(actual, "UserHostAddress=\"192.168.2.132\""))
+	assert.True(t, strings.Contains(actual, "[B@321"))
+	assert.True(t, strings.Contains(actual, "B=\"321\""))
+
 	// Test defaults
 	expected = "<165>1 2003-08-24T12:14:15.000003Z - - - - -\n"
 	logRecord = plog.NewLogRecord()