metric 등록 방법 변경

metric/common.go

@@ -0,0 +1,144 @@
+package metric
+
+import (
+	"crypto/md5"
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"math"
+	"os"
+	"path"
+	"strings"
+	"sync/atomic"
+
+	"repositories.action2quare.com/ayo/gocommon/logger"
+)
+
+const metric_value_line_size = 19
+
+type MetricDescription struct {
+	Key         string
+	Type        MetricType
+	Name        string            `json:",omitempty"`
+	Help        string            `json:",omitempty"`
+	ConstLabels map[string]string `json:",omitempty"`
+}
+
+type Exporter interface {
+	RegisterMetric(*MetricDescription)
+	UpdateMetric(string, float64)
+}
+
+type MetricWriter interface {
+	Add(int64)
+	Set(int64)
+}
+
+type metric_empty struct{}
+
+func (mw *metric_empty) Set(int64) {}
+func (mw *metric_empty) Add(int64) {}
+
+var MetricWriterNil = MetricWriter(&metric_empty{})
+
+type metric_int64 struct {
+	valptr *int64
+	buff   [metric_value_line_size]byte
+}
+
+func (mw *metric_int64) printOut() {
+	binary.LittleEndian.PutUint64(mw.buff[9:], math.Float64bits(float64(atomic.LoadInt64(mw.valptr))))
+	os.Stdout.Write(mw.buff[:])
+}
+
+func (mw *metric_int64) Set(newval int64) {
+	atomic.StoreInt64(mw.valptr, newval)
+	mw.printOut()
+}
+
+func (mw *metric_int64) Add(inc int64) {
+	atomic.AddInt64(mw.valptr, inc)
+	mw.printOut()
+}
+
+func NewMetric(mt MetricType, name string, help string, constLabels map[string]string) (writer MetricWriter) {
+	if !metricEnabled {
+		return MetricWriterNil
+	}
+
+	hash := md5.New()
+	hash.Write([]byte(name))
+	for k, v := range constLabels {
+		hash.Write([]byte(k))
+		hash.Write([]byte(v))
+	}
+
+	key := hex.EncodeToString(hash.Sum(nil))[:metric_key_size]
+	temp, _ := json.Marshal(MetricDescription{
+		Key:         key,
+		Type:        mt,
+		Name:        name,
+		Help:        help,
+		ConstLabels: constLabels,
+	})
+
+	impl := &metric_int64{
+		valptr: new(int64),
+	}
+
+	impl.buff[0] = METRIC_HEAD_INLINE
+	impl.buff[17] = METRIC_TAIL_INLINE
+	impl.buff[18] = '\n'
+	copy(impl.buff[1:], []byte(key))
+
+	output := append([]byte{METRIC_HEAD_INLINE}, temp...)
+	output = append(output, METRIC_TAIL_INLINE, '\n')
+	os.Stdout.Write(output)
+
+	// writer
+
+	return impl
+}
+
+func ReadMetricValue(line []byte) (string, float64) {
+	if len(line) < 16 {
+		return "", 0
+	}
+
+	key := string(line[0:8])
+	valbits := binary.LittleEndian.Uint64(line[8:])
+	val := math.Float64frombits(valbits)
+
+	return key, val
+}
+
+var metricEnabled = false
+
+func init() {
+	if path.Base(os.Args[0]) == "houston" {
+		logger.Println("metrics are going to be generated for myself(houston)")
+		metricEnabled = true
+		return
+	}
+
+	ppid := os.Getppid()
+	if parent, _ := os.FindProcess(ppid); parent != nil {
+		filename := fmt.Sprintf(`/proc/%d/stat`, os.Getppid())
+		if fn, err := os.ReadFile(filename); err == nil {
+			stats := strings.SplitN(string(fn), " ", 3)
+			parentname := strings.Trim(stats[1], "()")
+
+			if path.Base(parentname) == "houston" {
+				logger.Println("metrics are going to be generated for houston")
+				metricEnabled = true
+			} else {
+				logger.Println("metrics are NOT going to be generated. parent is not houston :", filename, string(fn))
+			}
+		} else {
+			logger.Println("metrics are NOT going to be generated. ppid proc is missing :", filename)
+		}
+	} else {
+		logger.Println("metrics are NOT going to be generated. parent process is missing. ppid :", ppid)
+	}
+}