Initial commit on gh-pages

monitoring/helpers.go

@@ -0,0 +1,173 @@
+package libpack_monitoring
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+	"sync"
+	"unicode"
+
+	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
+)
+
+var sortedLabelKeysCache = struct {
+	m sync.Map
+}{}
+
+func (ms *MetricsSetup) get_metrics_name(name string, labels map[string]string) string {
+	const unknownPodName = "unknown"
+	var buf bytes.Buffer
+
+	podName := getPodName()
+	if labels == nil {
+		labels = defaultLabels(podName)
+	} else {
+		ensureDefaultLabels(&labels, podName)
+	}
+
+	if ms.metrics_prefix != "" {
+		buf.WriteString(ms.metrics_prefix)
+		buf.WriteByte('_')
+	}
+	buf.WriteString(name)
+
+	if len(labels) > 0 {
+		buf.WriteByte('{')
+		appendSortedLabels(&buf, labels)
+		buf.WriteByte('}')
+	}
+
+	return buf.String()
+}
+
+func getPodName() string {
+	const unknownPodName = "unknown"
+	if hn, err := os.Hostname(); err == nil {
+		return hn
+	}
+	return unknownPodName
+}
+
+func defaultLabels(podName string) map[string]string {
+	return map[string]string{
+		"microservice": libpack_config.PKG_NAME,
+		"pod":          podName,
+	}
+}
+
+func ensureDefaultLabels(labels *map[string]string, podName string) {
+	if *labels == nil {
+		*labels = make(map[string]string)
+	}
+	if _, exists := (*labels)["microservice"]; !exists {
+		(*labels)["microservice"] = libpack_config.PKG_NAME
+	}
+	if _, exists := (*labels)["pod"]; !exists {
+		(*labels)["pod"] = podName
+	}
+}
+
+func appendSortedLabels(buf *bytes.Buffer, labels map[string]string) {
+	keys := getSortedKeys(labels)
+	for i, k := range keys {
+		if i > 0 {
+			buf.WriteByte(',')
+		}
+		buf.WriteString(k)
+		buf.WriteString(`="`)
+		buf.WriteString(labels[k])
+		buf.WriteByte('"')
+	}
+}
+
+func getSortedKeys(labels map[string]string) []string {
+	labelsKey := labelsToString(labels)
+
+	if keys, ok := sortedLabelKeysCache.m.Load(labelsKey); ok {
+		return keys.([]string)
+	}
+
+	keys := make([]string, 0, len(labels))
+	for k := range labels {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	sortedLabelKeysCache.m.Store(labelsKey, keys)
+
+	return keys
+}
+
+func labelsToString(labels map[string]string) string {
+	var sb strings.Builder
+	for k, v := range labels {
+		sb.WriteString(k)
+		sb.WriteByte('=')
+		sb.WriteString(v)
+		sb.WriteByte(';')
+	}
+	return sb.String()
+}
+
+func validate_metrics_name(name string) error {
+	cleanedName := clean_metric_name(name)
+
+	finalName := strings.Trim(cleanedName, "_")
+
+	if finalName != name {
+		return fmt.Errorf("invalid metric name: %s, expected %s", name, finalName)
+	}
+	return nil
+}
+
+func clean_metric_name(name string) string {
+	var buf bytes.Buffer
+	lastWasUnderscore := false
+
+	for _, r := range name {
+		if is_allowed_rune(r) {
+			if is_special_rune(r) {
+				if lastWasUnderscore {
+					continue
+				}
+				r = '_'
+				lastWasUnderscore = true
+			} else {
+				lastWasUnderscore = false
+			}
+			buf.WriteRune(r)
+		} else if !lastWasUnderscore {
+			buf.WriteByte('_')
+			lastWasUnderscore = true
+		}
+	}
+
+	return strings.Trim(buf.String(), "_")
+}
+
+func is_allowed_rune(r rune) bool {
+	return unicode.IsLetter(r) || unicode.IsDigit(r) || r == ' ' || r == '_'
+}
+
+func is_special_rune(r rune) bool {
+	return r == ' ' || r == '_'
+}
+
+func compile_metrics_with_labels(name string, labels map[string]string) string {
+	var buf bytes.Buffer
+
+	buf.WriteString(name)
+
+	keys := getSortedKeys(labels)
+
+	for _, k := range keys {
+		buf.WriteByte('_')
+		buf.WriteString(k)
+		buf.WriteByte('_')
+		buf.WriteString(labels[k])
+	}
+
+	return buf.String()
+}