[TrueCloudLab#26] Add billing metrics to separate registry

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

metrics/app.go

@@ -0,0 +1,74 @@
+package metrics
+
+import (
+	"net/http"
+	"sync"
+
+	"github.com/TrueCloudLab/frostfs-s3-gw/api"
+	"github.com/TrueCloudLab/frostfs-s3-gw/internal/frostfs"
+	"go.uber.org/zap"
+)
+
+type AppMetrics struct {
+	logger  *zap.Logger
+	gate    *GateMetrics
+	mu      sync.RWMutex
+	enabled bool
+}
+
+func NewAppMetrics(logger *zap.Logger, poolStatistics *frostfs.PoolStatistic, enabled bool) *AppMetrics {
+	if !enabled {
+		logger.Warn("metrics are disabled")
+	}
+	return &AppMetrics{
+		logger:  logger,
+		gate:    NewGateMetrics(poolStatistics),
+		enabled: enabled,
+	}
+}
+
+func (m *AppMetrics) SetEnabled(enabled bool) {
+	if !enabled {
+		m.logger.Warn("metrics are disabled")
+	}
+
+	m.mu.Lock()
+	m.enabled = enabled
+	m.mu.Unlock()
+}
+
+func (m *AppMetrics) SetHealth(status int32) {
+	if !m.isEnabled() {
+		return
+	}
+
+	m.gate.State.SetHealth(status)
+}
+
+func (m *AppMetrics) Shutdown() {
+	m.mu.Lock()
+	if m.enabled {
+		m.gate.State.SetHealth(0)
+		m.enabled = false
+	}
+	m.gate.Unregister()
+	m.mu.Unlock()
+}
+
+func (m *AppMetrics) isEnabled() bool {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return m.enabled
+}
+
+func (m *AppMetrics) Handler() http.Handler {
+	return m.gate.Handler()
+}
+
+func (m *AppMetrics) Update(user, bucket, cnrID string, reqType api.RequestType, in, out uint64) {
+	if !m.isEnabled() {
+		return
+	}
+
+	m.gate.Billing.apiStat.Update(user, bucket, cnrID, reqType, in, out)
+}