WIP

Change-Id: I5ff861f12cc1a0b00e2cd2289d6f51fd936b0e0a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

health/health.go

@@ -20,7 +20,6 @@ import (
 	"time"
 
 	"tailscale.com/envknob"
-	"tailscale.com/metrics"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tstime"
 	"tailscale.com/types/opt"
@@ -133,7 +132,7 @@ type Tracker struct {
 	lastLoginErr                error
 	localLogConfigErr           error
 	tlsConnectionErrors         map[string]error // map[ServerName]error
-	metricHealthMessage         *metrics.MultiLabelMap[metricHealthMessageLabel]
+	metricHealthMessage         *usermetric.MultiLabelMap[metricHealthMessageLabel]
 }
 
 // NewTracker contructs a new [Tracker] and attaches the given eventbus.

net/tstun/wrap.go

@@ -25,7 +25,6 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 	"tailscale.com/disco"
 	"tailscale.com/feature/buildfeatures"
-	tsmetrics "tailscale.com/metrics"
 	"tailscale.com/net/connstats"
 	"tailscale.com/net/packet"
 	"tailscale.com/net/packet/checksum"
@@ -214,8 +213,8 @@ type Wrapper struct {
 }
 
 type metrics struct {
-	inboundDroppedPacketsTotal  *tsmetrics.MultiLabelMap[usermetric.DropLabels]
-	outboundDroppedPacketsTotal *tsmetrics.MultiLabelMap[usermetric.DropLabels]
+	inboundDroppedPacketsTotal  *usermetric.MultiLabelMap[usermetric.DropLabels]
+	outboundDroppedPacketsTotal *usermetric.MultiLabelMap[usermetric.DropLabels]
 }
 
 func registerMetrics(reg *usermetric.Registry) *metrics {

util/usermetric/metrics.go

@@ -9,16 +9,11 @@ package usermetric
 
 import (
 	"sync"
-
-	"tailscale.com/metrics"
 )
 
 // Metrics contains user-facing metrics that are used by multiple packages.
 type Metrics struct {
 	initOnce sync.Once
-
-	droppedPacketsInbound  *metrics.MultiLabelMap[DropLabels]
-	droppedPacketsOutbound *metrics.MultiLabelMap[DropLabels]
 }
 
 // DropReason is the reason why a packet was dropped.
@@ -53,33 +48,13 @@ type DropLabels struct {
 	Reason DropReason
 }
 
-// initOnce initializes the common metrics.
-func (r *Registry) initOnce() {
-	r.m.initOnce.Do(func() {
-		r.m.droppedPacketsInbound = NewMultiLabelMapWithRegistry[DropLabels](
-			r,
-			"tailscaled_inbound_dropped_packets_total",
-			"counter",
-			"Counts the number of dropped packets received by the node from other peers",
-		)
-		r.m.droppedPacketsOutbound = NewMultiLabelMapWithRegistry[DropLabels](
-			r,
-			"tailscaled_outbound_dropped_packets_total",
-			"counter",
-			"Counts the number of packets dropped while being sent to other peers",
-		)
-	})
-}
-
 // DroppedPacketsOutbound returns the outbound dropped packet metric, creating it
 // if necessary.
-func (r *Registry) DroppedPacketsOutbound() *metrics.MultiLabelMap[DropLabels] {
-	r.initOnce()
-	return r.m.droppedPacketsOutbound
+func (r *Registry) DroppedPacketsOutbound() *MultiLabelMap[DropLabels] {
+	return &MultiLabelMap[DropLabels]{}
 }
 
 // DroppedPacketsInbound returns the inbound dropped packet metric.
-func (r *Registry) DroppedPacketsInbound() *metrics.MultiLabelMap[DropLabels] {
-	r.initOnce()
-	return r.m.droppedPacketsInbound
+func (r *Registry) DroppedPacketsInbound() *MultiLabelMap[DropLabels] {
+	return &MultiLabelMap[DropLabels]{}
 }

util/usermetric/usermetric.go

@@ -6,24 +6,19 @@
 package usermetric
 
 import (
-	"expvar"
-	"fmt"
 	"io"
 	"net/http"
-	"strings"
-
-	"tailscale.com/metrics"
-	"tailscale.com/tsweb/varz"
-	"tailscale.com/util/set"
 )
 
 // Registry tracks user-facing metrics of various Tailscale subsystems.
-type Registry struct {
-	vars expvar.Map
+type Registry struct{}
 
-	// m contains common metrics owned by the registry.
-	m Metrics
-}
+type noop struct{}
+
+type MultiLabelMap[T comparable] struct{}
+
+func (*MultiLabelMap[T]) Add(T, int64) {}
+func (*MultiLabelMap[T]) Set(T, any)   {}
 
 // NewMultiLabelMapWithRegistry creates and register a new
 // MultiLabelMap[T] variable with the given name and returns it.
@@ -32,88 +27,37 @@ type Registry struct {
 // Note that usermetric are not protected against duplicate
 // metrics name. It is the caller's responsibility to ensure that
 // the name is unique.
-func NewMultiLabelMapWithRegistry[T comparable](m *Registry, name string, promType, helpText string) *metrics.MultiLabelMap[T] {
-	ml := &metrics.MultiLabelMap[T]{
-		Type: promType,
-		Help: helpText,
-	}
-	var zero T
-	_ = metrics.LabelString(zero) // panic early if T is invalid
-	m.vars.Set(name, ml)
-	return ml
+func NewMultiLabelMapWithRegistry[T comparable](m *Registry, name string, promType, helpText string) *MultiLabelMap[T] {
+	return &MultiLabelMap[T]{}
 }
 
 // Gauge is a gauge metric with no labels.
-type Gauge struct {
-	m    *expvar.Float
-	help string
-}
+type Gauge struct{}
+
+var noopGauge = &Gauge{}
 
 // NewGauge creates and register a new gauge metric with the given name and help text.
-func (r *Registry) NewGauge(name, help string) *Gauge {
-	g := &Gauge{&expvar.Float{}, help}
-	r.vars.Set(name, g)
-	return g
-}
+func (r *Registry) NewGauge(name, help string) *Gauge { return noopGauge }
 
-// Set sets the gauge to the given value.
-func (g *Gauge) Set(v float64) {
-	if g == nil {
-		return
-	}
-	g.m.Set(v)
-}
+func (g *Gauge) Add(v float64) {}
+func (g *Gauge) Set(v float64) {}
 
-// String returns the string of the underlying expvar.Float.
-// This satisfies the expvar.Var interface.
-func (g *Gauge) String() string {
-	if g == nil {
-		return ""
-	}
-	return g.m.String()
-}
+// Set sets the gauge to the given value.
+func (noop) Set(v float64) {}
 
 // WritePrometheus writes the gauge metric in Prometheus format to the given writer.
 // This satisfies the varz.PrometheusWriter interface.
 func (g *Gauge) WritePrometheus(w io.Writer, name string) {
-	io.WriteString(w, "# TYPE ")
-	io.WriteString(w, name)
-	io.WriteString(w, " gauge\n")
-	if g.help != "" {
-		io.WriteString(w, "# HELP ")
-		io.WriteString(w, name)
-		io.WriteString(w, " ")
-		io.WriteString(w, g.help)
-		io.WriteString(w, "\n")
-	}
-
-	io.WriteString(w, name)
-	fmt.Fprintf(w, " %v\n", g.m.Value())
+	panic("")
 }
 
 // Handler returns a varz.Handler that serves the userfacing expvar contained
 // in this package.
 func (r *Registry) Handler(w http.ResponseWriter, req *http.Request) {
-	varz.ExpvarDoHandler(r.vars.Do)(w, req)
-}
-
-// String returns the string representation of all the metrics and their
-// values in the registry. It is useful for debugging.
-func (r *Registry) String() string {
-	var sb strings.Builder
-	r.vars.Do(func(kv expvar.KeyValue) {
-		fmt.Fprintf(&sb, "%s: %v\n", kv.Key, kv.Value)
-	})
-
-	return sb.String()
+	http.NotFound(w, req)
 }
 
 // Metrics returns the name of all the metrics in the registry.
 func (r *Registry) MetricNames() []string {
-	ret := make(set.Set[string])
-	r.vars.Do(func(kv expvar.KeyValue) {
-		ret.Add(kv.Key)
-	})
-
-	return ret.Slice()
+	return nil
 }