Rename the settings whose names do not say what they control (closes #234)

Applies the setting renames of the naming audit under the SWW_WAF_ and
SWW_RPROXY_ prefixes, with sneak's names for the IP reputation cache
time and the two time limits, which now take milliseconds. The rproxy
log field default_disposition becomes waf_backend_no_answer, and
config.Config and config.FromEnvironment become config.WAF and
config.WAFFromEnvironment. Go fields, test names and prose follow. No
aliases; nothing reads the old names.

Model: opus-5-5

internal/metrics/busiest.go

@@ -13,14 +13,15 @@ const other = "other"
 
 // busiest are the metrics by one thing the lookup finds of the client,
 // its country or its AS number, for requests whose client's is known.
-// The topN busiest countries or AS numbers, by their requests since the
-// start, have series of their own, and the others are counted under
-// other, so that there are never more than topN + 1 series. One that
-// drops out of the busiest loses its series, and its next requests are
-// counted under other; one that becomes one of them gets a series that
-// counts from then on. Each series therefore only ever goes up.
+// The busiestCount busiest countries or AS numbers, by their requests
+// since the start, have series of their own, and the others are counted
+// under other, so that there are never more than busiestCount + 1 series.
+// One that drops out of the busiest loses its series, and its next
+// requests are counted under other; one that becomes one of them gets a
+// series that counts from then on. Each series therefore only ever goes
+// up.
 type busiest struct {
-	topN int
+	busiestCount int
 
 	requests      *prometheus.CounterVec
 	requestBytes  *prometheus.CounterVec
@@ -38,9 +39,9 @@ type busiest struct {
 }
 
 // newCountries returns the metrics by country, with series of their own
-// for the topN busiest countries.
-func newCountries(topN int) *busiest {
-	countries := newBusiest(topN, "country", "the client's country")
+// for the busiestCount busiest countries.
+func newCountries(busiestCount int) *busiest {
+	countries := newBusiest(busiestCount, "country", "the client's country")
 	countries.refused = counterVec(
 		"sww_country_list_refusals_total",
 		"Requests SWW_WAF_EXCLUSIVELY_ALLOWED_COUNTRIES refused, by the client's country.",
@@ -51,18 +52,19 @@ func newCountries(topN int) *busiest {
 }
 
 // newASNs returns the metrics by AS number, with series of their own for
-// the topN busiest AS numbers.
-func newASNs(topN int) *busiest {
-	return newBusiest(topN, "asn", "the client's AS number")
+// the busiestCount busiest AS numbers.
+func newASNs(busiestCount int) *busiest {
+	return newBusiest(busiestCount, "asn", "the client's AS number")
 }
 
 // newBusiest returns the metrics by label, which is described as
-// description, with series of their own for the topN busiest values.
-func newBusiest(topN int, label, description string) *busiest {
+// description, with series of their own for the busiestCount busiest
+// values.
+func newBusiest(busiestCount int, label, description string) *busiest {
 	by := []string{label}
 
 	return &busiest{
-		topN: topN,
+		busiestCount: busiestCount,
 		requests: counterVec("sww_"+label+"_requests_total",
 			"Requests, by "+description+".", by),
 		requestBytes: counterVec("sww_"+label+"_request_bytes_total",
@@ -131,7 +133,7 @@ func (b *busiest) label(value string) string {
 		return value
 	}
 
-	if len(b.top) < b.topN {
+	if len(b.top) < b.busiestCount {
 		b.top[value] = true
 
 		return value

internal/metrics/metrics.go

@@ -61,12 +61,12 @@ type Metrics struct {
 }
 
 // New returns the metrics, with the Go runtime's and the process's own.
-// topN is how many countries and how many AS numbers get series of their
-// own (SWW_WAF_METRICS_TOP_N). Every metric carries instanceName
-// (SWW_WAF_INSTANCE_NAME) as its label instance.
+// busiestCount is how many countries and how many AS numbers get series of
+// their own (SWW_WAF_METRICS_BUSIEST_COUNTRIES_AND_ASNS). Every metric
+// carries instanceName (SWW_WAF_INSTANCE_NAME) as its label instance.
 //
 //nolint:funlen // a few lines for each metric, a list that grows with them
-func New(topN int, instanceName string) *Metrics {
+func New(busiestCount int, instanceName string) *Metrics {
 	byStatus := []string{"status_class", "action"}
 	byFile := []string{"file"}
 	registry := prometheus.NewRegistry()
@@ -102,7 +102,7 @@ func New(topN int, instanceName string) *Metrics {
 		}),
 		rateLimitHits: counterVec(
 			"sww_rate_limit_hits_total",
-			"Requests that broke a rate limit, a byte limit or the error burst, by "+
+			"Requests that broke a rate limit, a byte limit or the refusal limit, by "+
 				"its window and its kind, requests, bytes or refusals.",
 			[]string{"window", "kind"},
 		),
@@ -114,8 +114,8 @@ func New(topN int, instanceName string) *Metrics {
 				"and the rule's id.",
 			[]string{"mode", "rule_id"},
 		),
-		countries: newCountries(topN),
-		asns:      newASNs(topN),
+		countries: newCountries(busiestCount),
+		asns:      newASNs(busiestCount),
 		GeoJSRequests: prometheus.NewCounter(prometheus.CounterOpts{
 			Name: "sww_geojs_requests_total",
 			Help: "Requests to GeoJS.",
@@ -465,7 +465,7 @@ func (m *Metrics) RequestReported(
 }
 
 // LimitHit counts a request that broke a rate limit, a byte limit or the
-// error burst, by the window and the kind of hit.
+// refusal limit, by the window and the kind of hit.
 func (m *Metrics) LimitHit(hit ratelimit.Hit) {
 	m.rateLimitHits.WithLabelValues(hit.Window, hit.Kind).Inc()
 }