Rename the program to sww and its deciding daemon to discriminator

The program is now sww, built from cmd/sww, with two modes: sww rproxy and
sww discriminator. servewaf becomes discriminator everywhere it names that
daemon: the package (internal/discriminator), its types, functions, files, the
discriminator_line log field, and its docs and tests.

smallwebwaf is left only where sneak's directive allows it: the documents'
product name, the git.eeqj.de/sneak/smallwebwaf URLs, and the Go module path
sneak.berlin/go/smallwebwaf. Everywhere else a name containing it takes the sww
form: the package (internal/sww), metric names (sww_*), the X-Sww-* headers,
the /_sww/ admin endpoints, the SWW_COMMAND setting, the OS user, and the state
and rules directories.

No logic changes. make check passes.

Model: deepseek-v4-pro

internal/metrics/busiest.go

@@ -41,7 +41,7 @@ type busiest struct {
 // for the topN busiest countries.
 func newCountries(topN int) *busiest {
 	countries := newBusiest(topN, "country", "the client's country")
-	countries.refused = counterVec("smallwebwaf_country_list_refusals_total",
+	countries.refused = counterVec("sww_country_list_refusals_total",
 		"Requests the country lists refused, by the client's country.",
 		[]string{"country"})
 
@@ -61,11 +61,11 @@ func newBusiest(topN int, label, description string) *busiest {
 
 	return &busiest{
 		topN: topN,
-		requests: counterVec("smallwebwaf_"+label+"_requests_total",
+		requests: counterVec("sww_"+label+"_requests_total",
 			"Requests, by "+description+".", by),
-		requestBytes: counterVec("smallwebwaf_"+label+"_request_bytes_total",
+		requestBytes: counterVec("sww_"+label+"_request_bytes_total",
 			"Request body bytes, by "+description+".", by),
-		responseBytes: counterVec("smallwebwaf_"+label+"_response_bytes_total",
+		responseBytes: counterVec("sww_"+label+"_response_bytes_total",
 			"Response body bytes, by "+description+".", by),
 		seen: map[string]int64{},
 		top:  map[string]bool{},

internal/metrics/metrics.go

@@ -1,4 +1,4 @@
-// Package metrics keeps smallwebwaf's Prometheus metrics, as
+// Package metrics keeps sww's Prometheus metrics, as
 // docs/metrics.md lists them, and serves them in the Prometheus text
 // format, as the "Metrics endpoint" section of SPEC.md requires. No
 // metric carries a client's address.
@@ -22,7 +22,7 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/rules"
 )
 
-// Metrics are smallwebwaf's metrics. They are safe for concurrent use.
+// Metrics are sww's metrics. They are safe for concurrent use.
 type Metrics struct {
 	// registry gives every metric registered with it the label instance.
 	registry prometheus.Registerer
@@ -76,60 +76,60 @@ func New(topN int, instanceName string) *Metrics {
 			prometheus.Labels{"instance": instanceName}, registry),
 		handler: promhttp.HandlerFor(registry, promhttp.HandlerOpts{}),
 		inFlight: prometheus.NewGauge(prometheus.GaugeOpts{
-			Name: "smallwebwaf_requests_in_flight",
+			Name: "sww_requests_in_flight",
 			Help: "Requests under way.",
 		}),
-		requests: counterVec("smallwebwaf_requests_total",
+		requests: counterVec("sww_requests_total",
 			"Requests, by the class of their status and their action.", byStatus),
-		requestBytes: counterVec("smallwebwaf_request_bytes_total",
+		requestBytes: counterVec("sww_request_bytes_total",
 			"Request body bytes, by the class of the status and the action.",
 			byStatus),
-		responseBytes: counterVec("smallwebwaf_response_bytes_total",
+		responseBytes: counterVec("sww_response_bytes_total",
 			"Response body bytes, by the class of the status and the action.",
 			byStatus),
 		requestDuration: prometheus.NewHistogram(prometheus.HistogramOpts{
-			Name: "smallwebwaf_request_duration_seconds",
+			Name: "sww_request_duration_seconds",
 			Help: "How long requests took, from their arrival to their end.",
 		}),
 		upstreamDuration: prometheus.NewHistogram(prometheus.HistogramOpts{
-			Name: "smallwebwaf_upstream_duration_seconds",
+			Name: "sww_upstream_duration_seconds",
 			Help: "How long requests passed to the app took, from then to their end.",
 		}),
-		rateLimitHits: counterVec("smallwebwaf_rate_limit_hits_total",
+		rateLimitHits: counterVec("sww_rate_limit_hits_total",
 			"Requests that broke a rate limit, a byte limit or the error burst, by "+
 				"its window and its kind, requests, bytes or refusals.",
 			[]string{"window", "kind"}),
-		offences: counterVec("smallwebwaf_offences_total",
+		offences: counterVec("sww_offences_total",
 			"Offences, by kind.", []string{"kind"}),
-		wafMatches: counterVec("smallwebwaf_waf_matches_total",
+		wafMatches: counterVec("sww_waf_matches_total",
 			"Requests that matched a rule of the Core Rule Set, by SWWAF_WAF_MODE "+
 				"and the rule's id.", []string{"mode", "rule_id"}),
 		countries: newCountries(topN),
 		asns:      newASNs(topN),
 		GeoJSRequests: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "smallwebwaf_geojs_requests_total",
+			Name: "sww_geojs_requests_total",
 			Help: "Requests to GeoJS.",
 		}),
 		GeoJSFailures: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "smallwebwaf_geojs_failures_total",
+			Name: "sww_geojs_failures_total",
 			Help: "Requests to GeoJS that failed.",
 		}),
 		GeoJSUnanswered: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "smallwebwaf_geojs_unanswered_total",
+			Name: "sww_geojs_unanswered_total",
 			Help: "Requests that needed their client's answer from GeoJS and " +
 				"went on without it, because GeoJS had not given it in time.",
 		}),
-		stateFileWrites: counterVec("smallwebwaf_state_file_writes_total",
+		stateFileWrites: counterVec("sww_state_file_writes_total",
 			"Writes of each state file.", byFile),
-		stateFileWriteFailures: counterVec("smallwebwaf_state_file_write_failures_total",
+		stateFileWriteFailures: counterVec("sww_state_file_write_failures_total",
 			"Writes of each state file that failed.", byFile),
-		stateFileLastWrite: gaugeVec("smallwebwaf_state_file_last_write_timestamp_seconds",
+		stateFileLastWrite: gaugeVec("sww_state_file_last_write_timestamp_seconds",
 			"When each state file was last written, in seconds since 1970.", byFile),
-		stateFileSize: gaugeVec("smallwebwaf_state_file_size_bytes",
+		stateFileSize: gaugeVec("sww_state_file_size_bytes",
 			"The size of each state file, as it was last written.", byFile),
-		stateFileEditsTakenIn: counterVec("smallwebwaf_state_file_edits_taken_in_total",
+		stateFileEditsTakenIn: counterVec("sww_state_file_edits_taken_in_total",
 			"Edits of each state file taken in while running.", byFile),
-		stateFileEditsSetAside: counterVec("smallwebwaf_state_file_edits_set_aside_total",
+		stateFileEditsSetAside: counterVec("sww_state_file_edits_set_aside_total",
 			"Edits of each state file renamed to <name>.bad because they did not parse.",
 			byFile),
 	}
@@ -161,7 +161,7 @@ func (m *Metrics) AddBansAndClients(
 		bans.CauseLimit, bans.CauseAttack, bans.CauseAdmin, bans.CauseCrowdSec,
 	} {
 		m.registry.MustRegister(prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name:        "smallwebwaf_bans_made_total",
+			Name:        "sww_bans_made_total",
 			Help:        "Bans made, by cause.",
 			ConstLabels: prometheus.Labels{"cause": cause},
 		}, func() float64 {
@@ -171,7 +171,7 @@ func (m *Metrics) AddBansAndClients(
 
 	m.registry.MustRegister(
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_active_bans",
+			Name: "sww_active_bans",
 			Help: "Bans active now, the permanent ones included.",
 		}, func() float64 {
 			active, _ := ledger.Count(now())
@@ -179,7 +179,7 @@ func (m *Metrics) AddBansAndClients(
 			return float64(active)
 		}),
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_permanent_bans",
+			Name: "sww_permanent_bans",
 			Help: "Permanent bans not lifted.",
 		}, func() float64 {
 			_, permanent := ledger.Count(now())
@@ -187,7 +187,7 @@ func (m *Metrics) AddBansAndClients(
 			return float64(permanent)
 		}),
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_tracked_clients",
+			Name: "sww_tracked_clients",
 			Help: "Clients in the table of clients.",
 		}, func() float64 {
 			return float64(limiter.Len())
@@ -200,13 +200,13 @@ func (m *Metrics) AddBansAndClients(
 // ruleFiles, read as the metrics are asked for. It is called once, before
 // RuleMatched.
 func (m *Metrics) AddRules(ruleFiles *rules.Files) {
-	m.ruleMatches = counterVec("smallwebwaf_rule_matches_total",
+	m.ruleMatches = counterVec("sww_rule_matches_total",
 		"Requests that matched a rule of the rule files, by its id and action.",
 		[]string{"rule_id", "action"})
 
 	m.registry.MustRegister(m.ruleMatches,
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_rules_loaded",
+			Name: "sww_rules_loaded",
 			Help: "Rules loaded from the rule files.",
 		}, func() float64 {
 			return float64(ruleFiles.Len())
@@ -219,20 +219,20 @@ func (m *Metrics) AddRules(ruleFiles *rules.Files) {
 func (m *Metrics) AddRemoteLog(remote *remotelog.Sender) {
 	m.registry.MustRegister(
 		prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name: "smallwebwaf_remote_log_lines_sent_total",
+			Name: "sww_remote_log_lines_sent_total",
 			Help: "Log lines sent to SWWAF_LOG_REMOTE_URL.",
 		}, func() float64 {
 			return float64(remote.Sent())
 		}),
 		prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name: "smallwebwaf_remote_log_lines_dropped_total",
+			Name: "sww_remote_log_lines_dropped_total",
 			Help: "Log lines dropped: the oldest in a full buffer, and those " +
 				"whose sending failed.",
 		}, func() float64 {
 			return float64(remote.Dropped())
 		}),
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_remote_log_buffer_depth",
+			Name: "sww_remote_log_buffer_depth",
 			Help: "Log lines in the buffer, waiting to be sent.",
 		}, func() float64 {
 			return float64(remote.Depth())
@@ -248,13 +248,13 @@ func (m *Metrics) AddRemoteLog(remote *remotelog.Sender) {
 func (m *Metrics) AddLookupFile(lastRead func() time.Time, readFailures func() int) {
 	m.registry.MustRegister(
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_lookup_database_last_read_timestamp_seconds",
+			Name: "sww_lookup_database_last_read_timestamp_seconds",
 			Help: "When the lookup database in use was read, in seconds since 1970.",
 		}, func() float64 {
 			return float64(lastRead().Unix())
 		}),
 		prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name: "smallwebwaf_lookup_database_read_failures_total",
+			Name: "sww_lookup_database_read_failures_total",
 			Help: "Replacements of the lookup database that could not be read.",
 		}, func() float64 {
 			return float64(readFailures())
@@ -275,7 +275,7 @@ const sourceLabel = "source"
 // copy in use was fetched, and for a zone, the queries made and those that
 // failed. It is called once, before ReputationHit.
 func (m *Metrics) AddReputation(lists *reputation.Lists, dnsbl *reputation.DNSBL) {
-	m.reputationHits = counterVec("smallwebwaf_reputation_hits_total",
+	m.reputationHits = counterVec("sww_reputation_hits_total",
 		"Requests whose client a blocklist, the CrowdSec decision list, a DNSBL "+
 			"zone or AbuseIPDB lists, by the list's URL, the zone, or abuseipdb.",
 		[]string{sourceLabel})
@@ -294,7 +294,7 @@ func (m *Metrics) AddReputation(lists *reputation.Lists, dnsbl *reputation.DNSBL
 		m.addReputationFailures(source, func() int { return lists.Failures(listURL) })
 		m.registry.MustRegister(
 			prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-				Name: "smallwebwaf_reputation_last_fetch_timestamp_seconds",
+				Name: "sww_reputation_last_fetch_timestamp_seconds",
 				Help: "When the copy of the list in use was fetched, in seconds since " +
 					"1970, or 0 while there is none.",
 				ConstLabels: source,
@@ -321,7 +321,7 @@ func (m *Metrics) AddAbuseIPDB(abuseIPDB *reputation.AbuseIPDB) {
 	m.addReputationFailures(source, abuseIPDB.Failures)
 	m.registry.MustRegister(
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name:        "smallwebwaf_reputation_daily_budget_remaining",
+			Name:        "sww_reputation_daily_budget_remaining",
 			Help:        "Checks of the day's SWWAF_ABUSEIPDB_DAILY_BUDGET not yet spent.",
 			ConstLabels: source,
 		}, func() float64 {
@@ -348,21 +348,21 @@ func (m *Metrics) AddAlerts(queue *alerts.Queue) {
 
 		m.registry.MustRegister(
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name:        "smallwebwaf_alerts_sent_total",
+				Name:        "sww_alerts_sent_total",
 				Help:        "Alerts the destination took.",
 				ConstLabels: destination,
 			}, func() float64 {
 				return float64(queue.Counts(name).Sent)
 			}),
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name:        "smallwebwaf_alerts_failed_total",
+				Name:        "sww_alerts_failed_total",
 				Help:        "Requests to the destination that failed.",
 				ConstLabels: destination,
 			}, func() float64 {
 				return float64(queue.Counts(name).Failed)
 			}),
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name: "smallwebwaf_alerts_suppressed_total",
+				Name: "sww_alerts_suppressed_total",
 				Help: "Alerts held back: repeats within SWWAF_ALERT_COOLDOWN, and " +
 					"alerts past SWWAF_ALERT_MAX_PER_HOUR, for the hour's summary.",
 				ConstLabels: destination,
@@ -370,7 +370,7 @@ func (m *Metrics) AddAlerts(queue *alerts.Queue) {
 				return float64(queue.Suppressed())
 			}),
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name: "smallwebwaf_alerts_dropped_total",
+				Name: "sww_alerts_dropped_total",
 				Help: "Alerts dropped, the oldest first, from a full queue, and " +
 					"alerts given up as the destination refused them.",
 				ConstLabels: destination,
@@ -467,7 +467,7 @@ func (m *Metrics) StateFileWritten(name string, size int, err error) {
 }
 
 // StateFileEditTakenIn counts an admin's edit of the state file name
-// taken in while smallwebwaf runs.
+// taken in while sww runs.
 func (m *Metrics) StateFileEditTakenIn(name string) {
 	m.stateFileEditsTakenIn.WithLabelValues(name).Inc()
 }
@@ -506,7 +506,7 @@ func (m *Metrics) count(
 // zone, or of the checks of clients with AbuseIPDB, which count tells.
 func (m *Metrics) addReputationQueries(source prometheus.Labels, count func() int) {
 	m.registry.MustRegister(prometheus.NewCounterFunc(prometheus.CounterOpts{
-		Name:        "smallwebwaf_reputation_queries_total",
+		Name:        "sww_reputation_queries_total",
 		Help:        "Queries to the DNSBL zone, or checks of clients with AbuseIPDB.",
 		ConstLabels: source,
 	}, func() float64 {
@@ -519,7 +519,7 @@ func (m *Metrics) addReputationQueries(source prometheus.Labels, count func() in
 // that failed, which count tells.
 func (m *Metrics) addReputationFailures(source prometheus.Labels, count func() int) {
 	m.registry.MustRegister(prometheus.NewCounterFunc(prometheus.CounterOpts{
-		Name: "smallwebwaf_reputation_failures_total",
+		Name: "sww_reputation_failures_total",
 		Help: "Fetches of the list, queries to the DNSBL zone, or checks with " +
 			"AbuseIPDB, that failed.",
 		ConstLabels: source,