Read every setting through viper and rename the settings (closes #211)

Every setting of discriminator and rproxy is read through viper, in place
of the os.LookupEnv function Main passed down. NewViper turns AutomaticEnv
and AllowEmptyEnv on, so a setting that is set but empty reads as set. A
setting may also be given as a file, the _FILE form, which rproxy's
settings now have too; rproxy still writes nothing to disk.

The settings are renamed. Discriminator's take the prefix SWW_WAF_,
rproxy's take SWW_RPROXY_, and the shared SWW_COMMAND keeps SWW_. The Core
Rule Set's settings take SWW_WAF_CORE_RULE_SET_ rather than SWW_WAF_WAF_.
Every place a name appeared changed: the code, the viper keys, tests,
documents, examples, the README's settings table and the image files.

Model: deepseek-v4-pro

internal/discriminator/reputation_test.go

@@ -23,12 +23,12 @@ import (
 
 // The reputation settings.
 const (
-	blocklistURLs      = "SWW_BLOCKLIST_URLS"
-	blocklistAction    = "SWW_BLOCKLIST_ACTION"
-	asnLimitPercentURL = "SWW_ASN_LIMIT_PERCENT_URL"
+	blocklistURLs      = "SWW_WAF_BLOCKLIST_URLS"
+	blocklistAction    = "SWW_WAF_BLOCKLIST_ACTION"
+	asnLimitPercentURL = "SWW_WAF_ASN_LIMIT_PERCENT_URL"
 )
 
-// The actions of SWW_BLOCKLIST_ACTION and SWW_REPUTATION_ACTION:
+// The actions of SWW_WAF_BLOCKLIST_ACTION and SWW_WAF_REPUTATION_ACTION:
 // limitHalf gives a listed client half of every limit, and limitQuarter a
 // quarter.
 const (
@@ -127,7 +127,7 @@ func TestBlocklistsComeAfterTheCountryListsAndSkipAllowNets(t *testing.T) {
 	loadLists(t, server, map[string][]string{dropURL: {fromDE, fromKP}})
 
 	// fromKP's country refuses it before the list is looked at, and fromDE,
-	// in SWW_ALLOW_NETS, is not checked at all: neither is noted, nor
+	// in SWW_WAF_ALLOW_NETS, is not checked at all: neither is noted, nor
 	// alerted.
 	wantReputation(t, s.get(fromKP, http.StatusForbidden, requestlog.ActionCountryDenied))
 	wantReputation(t, s.get(fromDE, http.StatusOK, requestlog.ActionForward))
@@ -224,7 +224,7 @@ func TestASNLimitPercentFileCountsAsTheSettingDoesTheLowerWinning(t *testing.T)
 		},
 		{"none, for an AS number the file does not list", nil, asnKP + ":25", none, none},
 		{
-			"SWW_ASN_BYTES_PERCENT's in place of the file's for the byte limits",
+			"SWW_WAF_ASN_BYTES_PERCENT's in place of the file's for the byte limits",
 			map[string]string{asnBytesPercent: asnDE + ":100"}, asnDEQuarter, fromURL, none,
 		},
 	} {
@@ -312,9 +312,9 @@ func TestEachBlocklistThatListsAClientRaisesAnAlertOncePerCooldownAndIsCounted(
 
 // The DNSBL settings.
 const (
-	dnsblZones       = "SWW_DNSBL_ZONES"
-	dnsblResolver    = "SWW_DNSBL_RESOLVER"
-	reputationAction = "SWW_REPUTATION_ACTION"
+	dnsblZones       = "SWW_WAF_DNSBL_ZONES"
+	dnsblResolver    = "SWW_WAF_DNSBL_RESOLVER"
+	reputationAction = "SWW_WAF_REPUTATION_ACTION"
 )
 
 // The DNSBL zones these tests name, which are never asked about the
@@ -370,7 +370,7 @@ func TestEachReputationActionForAClientADNSBLZoneLists(t *testing.T) {
 			for _, from := range []string{fromDE, fromKP} {
 				for i := range 3 {
 					line := s.get(from, tc.statuses[i], tc.actions[i])
-					// In the order SWW_DNSBL_ZONES names them.
+					// In the order SWW_WAF_DNSBL_ZONES names them.
 					wantReputation(t, line, listedBy[from]...)
 					wantPercent(t, "limit_percent", line.LimitPercent,
 						line.LimitPercentSetting, tc.percent)
@@ -416,7 +416,7 @@ func TestDNSBLZonesComeAfterTheBlocklistsAndSkipAllowNets(t *testing.T) {
 	loadVerdicts(server, map[string][]string{fromKP: {dnsblZone}, fromDE: {dnsblZone}})
 
 	// The blocklist refuses fromKP before its verdict is looked at, and
-	// fromDE, in SWW_ALLOW_NETS, is not checked at all: neither is noted
+	// fromDE, in SWW_WAF_ALLOW_NETS, is not checked at all: neither is noted
 	// for the zone, nor alerted, nor asked about.
 	wantReputation(t, s.get(fromKP, http.StatusForbidden, requestlog.ActionDenied),
 		dropURL)
@@ -609,7 +609,7 @@ func TestRequestFromAClientWithoutAVerdictHasTheZoneAskedAboutIt(t *testing.T) {
 
 // The AbuseIPDB settings, and accountKey, the key the tests set.
 const (
-	abuseIPDBKey = "SWW_ABUSEIPDB_KEY"
+	abuseIPDBKey = "SWW_WAF_ABUSEIPDB_KEY"
 	accountKey   = "abuseipdb-key-0123456789abcdef"
 )
 
@@ -800,7 +800,7 @@ func TestEachReputationActionForAClientAbuseIPDBScoresAtOrOverTheMinimum(t *test
 				rateLimitPerMinute: fourAMinute, abuseIPDBKey: accountKey,
 				reputationAction: tc.action,
 			})
-			// At SWW_ABUSEIPDB_MIN_SCORE, 75 by default, and just under it.
+			// At SWW_WAF_ABUSEIPDB_MIN_SCORE, 75 by default, and just under it.
 			loadScores(server, map[string]int64{fromDE: 75, fromKP: 74})
 
 			for i := range 3 {
@@ -851,7 +851,7 @@ func TestAbuseIPDBHitRaisesAnAlertWithTheScoreOncePerCooldownAndIsCounted(
 	// The alert is made as a DNSBL zone's is, with the score besides.
 	waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
 	if len(waiting) != 1 || waiting[0].Event != alerts.EventReputationHit ||
-		waiting[0].Reason != "scored by AbuseIPDB at or over SWW_ABUSEIPDB_MIN_SCORE" ||
+		waiting[0].Reason != "scored by AbuseIPDB at or over SWW_WAF_ABUSEIPDB_MIN_SCORE" ||
 		waiting[0].Detail["source"] != abuseipdb || waiting[0].Detail["score"] != int64(90) ||
 		queue.Suppressed() != 1 {
 		t.Errorf("alerts waiting %+v, %d held back, want AbuseIPDB's reputation_hit "+
@@ -922,7 +922,7 @@ func TestBanNotesNameEachReputationSourceThatListedTheClient(t *testing.T) {
 				abuseIPDBKey: accountKey, reputationAction: actionLog,
 			})
 			// Every source lists client, and none otherClient, whose score is
-			// under SWW_ABUSEIPDB_MIN_SCORE, 75 by default.
+			// under SWW_WAF_ABUSEIPDB_MIN_SCORE, 75 by default.
 			loadLists(t, server, map[string][]string{dropURL: {client}})
 			loadVerdicts(server, map[string][]string{client: {dnsblZone}, otherClient: nil})
 			loadScores(server, map[string]int64{client: score, otherClient: 74})
@@ -971,7 +971,7 @@ func verdictsFetched() time.Time {
 }
 
 // loadVerdicts puts into server's DNSBL, for each client listedBy names,
-// a verdict of each zone SWW_DNSBL_ZONES names, fetched at
+// a verdict of each zone SWW_WAF_DNSBL_ZONES names, fetched at
 // verdictsFetched, as reputation.json would at start: one that lists the
 // client from each zone listedBy gives for it, and one that does not from
 // each other zone.