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