feat(pkger): add metrics svc middleware

cmd/influxd/launcher/launcher.go

@@ -831,6 +831,7 @@ func (m *Launcher) run(ctx context.Context) (err error) {
 			pkger.WithVariableSVC(authorizer.NewVariableService(b.VariableService)),
 		)
 		pkgSVC = pkger.MWTracing()(pkgSVC)
+		pkgSVC = pkger.MWMetrics(m.reg)(pkgSVC)
 		pkgSVC = pkger.MWLogging(pkgerLogger)(pkgSVC)
 	}
 

kit/metric/client.go

@@ -0,0 +1,73 @@
+package metric
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/influxdata/influxdb"
+	"github.com/influxdata/influxdb/kit/prom"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// REDClient is a metrics client for collection RED metrics.
+type REDClient struct {
+	// RED metrics
+	reqs *prometheus.CounterVec
+	errs *prometheus.CounterVec
+	durs *prometheus.HistogramVec
+}
+
+// New creates a new REDClient.
+func New(reg *prom.Registry, service string) *REDClient {
+	// MiddlewareMetrics is a metrics service middleware for the notification endpoint service.
+	const namespace = "service"
+
+	reqs := prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: namespace,
+		Subsystem: service,
+		Name:      "call_total",
+		Help:      fmt.Sprintf("Number of calls to the %s service", service),
+	}, []string{"method"})
+
+	errs := prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: namespace,
+		Subsystem: service,
+		Name:      "error_total",
+		Help:      fmt.Sprintf("Number of errors encountered when calling the %s service", service),
+	}, []string{"method", "code"})
+
+	durs := prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: namespace,
+		Subsystem: service,
+		Name:      "duration",
+		Help:      fmt.Sprintf("Duration of %s service calls", service),
+	}, []string{"method"})
+
+	reg.MustRegister(reqs, errs, durs)
+
+	return &REDClient{
+		reqs: reqs,
+		errs: errs,
+		durs: durs,
+	}
+}
+
+// Record returns a record fn that is called on any given return err. If an error is encountered
+// it will register the err metric. The err is never altered.
+func (c *REDClient) Record(method string) func(error) error {
+	start := time.Now()
+	return func(err error) error {
+		c.reqs.With(prometheus.Labels{"method": method})
+
+		if err != nil {
+			c.errs.With(prometheus.Labels{
+				"method": method,
+				"code":   influxdb.ErrorCode(err),
+			}).Inc()
+		}
+
+		c.durs.With(prometheus.Labels{"method": method}).Observe(time.Since(start).Seconds())
+
+		return err
+	}
+}

pkger/service_metrics.go

@@ -0,0 +1,46 @@
+package pkger
+
+import (
+	"context"
+
+	"github.com/influxdata/influxdb"
+	"github.com/influxdata/influxdb/kit/metric"
+	"github.com/influxdata/influxdb/kit/prom"
+)
+
+type mwMetrics struct {
+	// RED metrics
+	rec *metric.REDClient
+
+	next SVC
+}
+
+var _ SVC = (*mwMetrics)(nil)
+
+// MWMetrics is a metrics service middleware for the notification endpoint service.
+func MWMetrics(reg *prom.Registry) SVCMiddleware {
+	return func(svc SVC) SVC {
+		return &mwMetrics{
+			rec:  metric.New(reg, "pkger"),
+			next: svc,
+		}
+	}
+}
+
+func (s *mwMetrics) CreatePkg(ctx context.Context, setters ...CreatePkgSetFn) (*Pkg, error) {
+	rec := s.rec.Record("create_pkg")
+	pkg, err := s.next.CreatePkg(ctx, setters...)
+	return pkg, rec(err)
+}
+
+func (s *mwMetrics) DryRun(ctx context.Context, orgID, userID influxdb.ID, pkg *Pkg) (Summary, Diff, error) {
+	rec := s.rec.Record("dry_run")
+	sum, diff, err := s.next.DryRun(ctx, orgID, userID, pkg)
+	return sum, diff, rec(err)
+}
+
+func (s *mwMetrics) Apply(ctx context.Context, orgID, userID influxdb.ID, pkg *Pkg, opts ...ApplyOptFn) (Summary, error) {
+	rec := s.rec.Record("apply")
+	sum, err := s.next.Apply(ctx, orgID, userID, pkg, opts...)
+	return sum, rec(err)
+}