[AlibabaCloudLogService] sanitize labels for metrics (#3454)

* sanitize metric labels for AlibabaCloudLogService metrics (#3429)

* add new lines at end of file

* refine code

* refine code as review comments

exporter/alibabacloudlogserviceexporter/metricsdata_to_logservice.go

@@ -51,9 +51,13 @@ func (kv *KeyValues) Swap(i, j int) {
 	kv.keyValues[i], kv.keyValues[j] = kv.keyValues[j], kv.keyValues[i]
 }
 func (kv *KeyValues) Less(i, j int) bool { return kv.keyValues[i].Key < kv.keyValues[j].Key }
-func (kv *KeyValues) Sort()              { sort.Sort(kv) }
+
+func (kv *KeyValues) Sort() {
+	sort.Sort(kv)
+}
 
 func (kv *KeyValues) Replace(key, value string) {
+	key = sanitize(key)
 	findIndex := sort.Search(len(kv.keyValues), func(index int) bool {
 		return kv.keyValues[index].Key >= key
 	})
@@ -64,14 +68,12 @@ func (kv *KeyValues) Replace(key, value string) {
 
 func (kv *KeyValues) AppendMap(mapVal map[string]string) {
 	for key, value := range mapVal {
-		kv.keyValues = append(kv.keyValues, KeyValue{
-			Key:   key,
-			Value: value,
-		})
+		kv.Append(key, value)
 	}
 }
 
 func (kv *KeyValues) Append(key, value string) {
+	key = sanitize(key)
 	kv.keyValues = append(kv.keyValues, KeyValue{
 		key,
 		value,

exporter/alibabacloudlogserviceexporter/metricsdata_to_logservice_test.go

@@ -170,3 +170,16 @@ func TestMetricCornerCases(t *testing.T) {
 	})
 	assert.Equal(t, label.String(), "a#$#b")
 }
+
+func TestMetricLabelSanitize(t *testing.T) {
+	var label KeyValues
+	label.Append("_test", "key_test")
+	label.Append("0test", "key_0test")
+	label.AppendMap(map[string]string{
+		"test_normal": "test_normal",
+		"0test":       "key_0test",
+	})
+	assert.Equal(t, label.String(), "key_test#$#key_test|key_0test#$#key_0test|test_normal#$#test_normal|key_0test#$#key_0test")
+	label.Sort()
+	assert.Equal(t, label.String(), "key_0test#$#key_0test|key_0test#$#key_0test|key_test#$#key_test|test_normal#$#test_normal")
+}

exporter/alibabacloudlogserviceexporter/sanitize.go

@@ -0,0 +1,52 @@
+// Copyright 2020, OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package alibabacloudlogserviceexporter
+
+import (
+	"strings"
+	"unicode"
+)
+
+// The code for sanitize is mostly copied from:
+//  https://github.com/open-telemetry/opentelemetry-collector/blob/2e84285efc665798d76773b9901727e8836e9d8f/exporter/prometheusexporter/sanitize.go
+
+// sanitize replaces non-alphanumeric characters with underscores in s.
+func sanitize(s string) string {
+	if len(s) == 0 {
+		return s
+	}
+
+	// Note: No length limit for label keys because Prometheus doesn't
+	// define a length limit, thus we should NOT be truncating label keys.
+	// See https://github.com/orijtech/prometheus-go-metrics-exporter/issues/4.
+
+	s = strings.Map(sanitizeRune, s)
+	if unicode.IsDigit(rune(s[0])) {
+		s = "key_" + s
+	}
+	if s[0] == '_' {
+		s = "key" + s
+	}
+	return s
+}
+
+// converts anything that is not a letter or digit to an underscore
+func sanitizeRune(r rune) rune {
+	if unicode.IsLetter(r) || unicode.IsDigit(r) {
+		return r
+	}
+	// Everything else turns into an underscore
+	return '_'
+}

exporter/alibabacloudlogserviceexporter/sanitize_test.go

@@ -0,0 +1,32 @@
+// Copyright 2020, OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package alibabacloudlogserviceexporter
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// The code for sanitize is mostly copied from:
+//  https://github.com/open-telemetry/opentelemetry-collector/blob/2e84285efc665798d76773b9901727e8836e9d8f/exporter/prometheusexporter/sanitize_test.go
+
+func TestSanitize(t *testing.T) {
+	require.Equal(t, "", sanitize(""), "")
+	require.Equal(t, "key_test", sanitize("_test"))
+	require.Equal(t, "key_0test", sanitize("0test"))
+	require.Equal(t, "test", sanitize("test"))
+	require.Equal(t, "test__", sanitize("test_/"))
+}