Read every setting through viper (closes #211)

servewaf's and rproxy's settings are read through viper, bound to the same environment variable names as before, 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, as it did. The _FILE forms, their errors, and rproxy reading no file form are unchanged, and the settings tests pass set into a viper instead of a lookup function.

Model: deepseek-v4-pro

Makefile

@@ -1,5 +1,5 @@
-.PHONY: bootstrap setup test lint fmt fmt-check tidy check docker publish \
+.PHONY: bootstrap setup test lint fmt fmt-check tidy check docker hooks build \
-	hooks build run example-app gitea-requests gitea-setup
+	run example-app gitea-requests gitea-setup
 
 # Makefile targets are thin shims; the implementations live in script/
 # per the scripts-to-rule-them-all pattern (see the Entrypoints section
@@ -7,8 +7,7 @@
 # which test checks. build and run are for working on the code by hand;
 # example-app checks the image with an app built on it; gitea-requests
 # reports the gitea requests the Core Rule Set refuses at the defaults;
-# gitea-setup checks the setup in deploy/gitea; publish builds the image
+# gitea-setup checks the setup in deploy/gitea.
-# on the Docker host and pushes it to the registry.
 
 bootstrap:
 	@script/bootstrap
@@ -37,9 +36,6 @@ check:
 docker:
 	@script/docker
 
-publish:
-	@script/publish
-
 hooks:
 	@script/install-precommit
 

README.md

@@ -743,11 +743,6 @@ on the host.
   `make check`.
 - `script/docker`: builds the image, whose build runs the tests and the linter
   first. `make docker`.
-- `script/publish`: runs `script/docker` on the Docker host `DOCKER_HOST`
-  (`ssh://root@fsn1app1` unless set) and pushes the image to `PUBLISH_IMAGE`
-  (`git.eeqj.de/sneak/smallwebwaf` unless set) under four tags: the UTC date as
-  `YYYY-MM-DD`, the short commit hash, the branch name and `latest`. Refuses a
-  working tree with uncommitted changes. `make publish`.
 - `script/cibuild`: what CI runs: `script/bootstrap`, `script/check`, then the
   image build.
 - `script/precommit`: run by the git pre-commit hook; runs `script/check`.

go.mod

@@ -10,12 +10,14 @@ require (
 	github.com/maxmind/mmdbwriter v1.2.0
 	github.com/oschwald/maxminddb-golang/v2 v2.7.0
 	github.com/prometheus/client_golang v1.24.1
+	github.com/spf13/viper v1.21.0
 )
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/corazawaf/libinjection-go v0.3.3 // indirect
+	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
 	github.com/goccy/go-json v0.10.5 // indirect
 	github.com/goccy/go-yaml v1.19.2 // indirect
 	github.com/gotnospirit/makeplural v0.0.0-20180622080156-a5f48d94d976 // indirect
@@ -25,14 +27,22 @@ require (
 	github.com/kylelemons/godebug v1.1.0 // indirect
 	github.com/magefile/mage v1.17.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
 	github.com/petar-dambovaliev/aho-corasick v0.0.0-20250424160509-463d218d4745 // indirect
 	github.com/prometheus/client_model v0.6.2 // indirect
 	github.com/prometheus/common v0.70.1 // indirect
 	github.com/prometheus/procfs v0.21.1 // indirect
+	github.com/sagikazarmark/locafero v0.11.0 // indirect
+	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
+	github.com/spf13/afero v1.15.0 // indirect
+	github.com/spf13/cast v1.10.0 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/tidwall/gjson v1.18.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/valllabh/ocsf-schema-golang v1.0.3 // indirect
+	go.yaml.in/yaml/v3 v3.0.5 // indirect
 	go4.org/netipx v0.0.0-20231129151722-fdeea329fbba // indirect
 	golang.org/x/net v0.58.0 // indirect
 	golang.org/x/sync v0.23.0 // indirect

go.sum

@@ -12,8 +12,12 @@ github.com/corazawaf/libinjection-go v0.3.3 h1:NhbXKRfRpqKzBMzv8zpCcnjyEw7BCVhBO
 github.com/corazawaf/libinjection-go v0.3.3/go.mod h1:Ik/+w3UmTWH9yn366RgS9D95K3y7Atb5m/H/gXzzPCk=
 github.com/foxcpp/go-mockdns v1.2.0 h1:omK3OrHRD1IWJz1FuFBCFquhXslXoF17OvBS6JPzZF0=
 github.com/foxcpp/go-mockdns v1.2.0/go.mod h1:IhLeSFGed3mJIAXPH2aiRQB+kqz7oqu8ld2qVbOu7Wk=
+github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
+github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.10.1 h1:b0/UzAf9yR5rhf3RPm9gf3ehBPpf0oZKIjtpKrx59Ho=
 github.com/fsnotify/fsnotify v1.10.1/go.mod h1:TLheqan6HD6GBK6PrDWyDPBaEV8LspOxvPSjC+bVfgo=
+github.com/go-viper/mapstructure/v2 v2.4.0 h1:EBsztssimR/CONLSZZ04E8qAkxNYq4Qp9LvH92wZUgs=
+github.com/go-viper/mapstructure/v2 v2.4.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
 github.com/goccy/go-json v0.10.5 h1:Fq85nIqj+gXn/S5ahsiTlK3TmC85qgirsdTP/+DeaC4=
 github.com/goccy/go-json v0.10.5/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
 github.com/goccy/go-yaml v1.19.2 h1:PmFC1S6h8ljIz6gMRBopkjP1TVT7xuwrButHID66PoM=
@@ -34,6 +38,10 @@ github.com/kaptinlin/jsonschema v0.4.6 h1:vOSFg5tjmfkOdKg+D6Oo4fVOM/pActWu/ntkPs
 github.com/kaptinlin/jsonschema v0.4.6/go.mod h1:1DUd7r5SdyB2ZnMtyB7uLv64dE3zTFTiYytDCd+AEL0=
 github.com/klauspost/compress v1.19.1 h1:VsB4HPswih7mmZ8WleSFQ75c/Ui1M4trX5oAsJnhSlk=
 github.com/klauspost/compress v1.19.1/go.mod h1:cwPg85FWrGar70rWktvGQj8/hthj3wpl0PGDogxkrSQ=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/magefile/mage v1.17.0 h1:dS4tkq997Ism03akafC8509iqDjeE7TNTexI25Y7sXM=
@@ -58,8 +66,24 @@ github.com/prometheus/common v0.70.1 h1:1HvjP4D5oL3t8RsPlwxA9onvvStjtIHYE5XuuwOi
 github.com/prometheus/common v0.70.1/go.mod h1:VdFUQDMZK3VLkurFUVhia6uys/0suUp86TJz5qbJRhc=
 github.com/prometheus/procfs v0.21.1 h1:GljZCt+zSTS+NZq88cyQ1LjZ+RCHp3uVuabBWA5+OJI=
 github.com/prometheus/procfs v0.21.1/go.mod h1:aB55Cww9pdSJVHk0hUf0inxWyyjPogFIjmHKYgMKmtY=
+github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+github.com/sagikazarmark/locafero v0.11.0 h1:1iurJgmM9G3PA/I+wWYIOw/5SyBtxapeHDcg+AAIFXc=
+github.com/sagikazarmark/locafero v0.11.0/go.mod h1:nVIGvgyzw595SUSUE6tvCp3YYTeHs15MvlmU87WwIik=
+github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 h1:+jumHNA0Wrelhe64i8F6HNlS8pkoyMv5sreGx2Ry5Rw=
+github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8/go.mod h1:3n1Cwaq1E1/1lhQhtRK2ts/ZwZEhjcQeJQ1RuC6Q/8U=
+github.com/spf13/afero v1.15.0 h1:b/YBCLWAJdFWJTN9cLhiXXcD7mzKn9Dm86dNnfyQw1I=
+github.com/spf13/afero v1.15.0/go.mod h1:NC2ByUVxtQs4b3sIUphxK0NioZnmxgyCrfzeuq8lxMg=
+github.com/spf13/cast v1.10.0 h1:h2x0u2shc1QuLHfxi+cTJvs30+ZAHOGRic8uyGTDWxY=
+github.com/spf13/cast v1.10.0/go.mod h1:jNfB8QC9IA6ZuY2ZjDp0KtFO2LZZlg4S/7bzP6qqeHo=
+github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
+github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/spf13/viper v1.21.0 h1:x5S+0EU27Lbphp4UKm1C+1oQO+rKx36vfCoaVebLFSU=
+github.com/spf13/viper v1.21.0/go.mod h1:P0lhsswPGWD/1lZJ9ny3fYnVqxiegrlNrEmgLjbTCAY=
 github.com/stretchr/testify v1.12.1 h1:EuwCh5fleGS7H32xRwO3wRGT7DxrDhLAT6FF8MpWDWE=
 github.com/stretchr/testify v1.12.1/go.mod h1:MDEgiDPPsNp5cuIrHPPCyornHKgEVbtFUmoNlxoYthg=
+github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
+github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 github.com/tidwall/gjson v1.18.0 h1:FIDeeyB800efLX89e5a8Y0BNH+LOngJyGrIWxG2FKQY=
 github.com/tidwall/gjson v1.18.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=

internal/config/config.go

@@ -7,9 +7,6 @@
 // the image runs.
 package config
 
-// FIXME: the rproxy config is in rproxy.go, the servewaf is in config.go -
-// wrong and inconsistent.
-
 import (
 	"crypto/x509"
 	"errors"
@@ -29,6 +26,8 @@ import (
 	"unicode"
 	"unicode/utf8"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/anomaly"
 	"sneak.berlin/go/smallwebwaf/internal/remotelog"
@@ -366,14 +365,11 @@ var (
 		"is not a header name such as accept-language")
 	errHeaderTakenOut = errors.New(
 		"is taken out of every request by Go's HTTP server, so it can never " +
-			"be logged",
+			"be logged")
-	)
 	errOnBothLists     = errors.New("is in SWWAF_DENIED_COUNTRIES too")
 	errNotLookupSource = errors.New("is not geojs, file or off")
 	errNeedsLookups    = errors.New("it needs each client looked up")
-	errNeedsDBPath     = errors.New(
+	errNeedsDBPath     = errors.New("it names the file to look clients up in")
-		"it names the file to look clients up in",
-	)
 	errDBPathUnused    = errors.New("only file reads it")
 	errOver64K         = errors.New(
 		"is more than 64K, the most servewaf gets of a body")
@@ -400,29 +396,22 @@ var (
 	errNotPathPrefix = errors.New(
 		"is not a path prefix starting with /, such as /assets/")
 	errNotTrapPath = errors.New(
-		"is not a path starting with / and without a ?, such as /wp-login.php",
+		"is not a path starting with / and without a ?, such as /wp-login.php")
-	)
 	errNotWAFMode       = errors.New("is not off, detect or block")
 	errNotParanoiaLevel = errors.New("is not a paranoia level, from 1 to 4")
 	errNotRuleID        = errors.New(
-		"is not the id of a Core Rule Set rule, a whole number such as 942100",
+		"is not the id of a Core Rule Set rule, a whole number such as 942100")
-	)
 	errSetupRuleID = errors.New(
 		"is from 900000 to 900999, the ids of the rules that set the Core Rule Set " +
-			"up and of smallwebwaf's own, which cannot be switched off",
+			"up and of smallwebwaf's own, which cannot be switched off")
-	)
 	errNotBoolean      = errors.New("is not true or false")
 	errNotLogRemoteURL = errors.New(
 		"is not syslog+udp, syslog+tcp or syslog+tls with a host and a port, " +
-			"and nothing more, such as syslog+tls://logs.example:6514",
+			"and nothing more, such as syslog+tls://logs.example:6514")
-	)
 	errNoCertificate = errors.New("holds no PEM certificate")
-	errNotFacility   = errors.New(
+	errNotFacility   = errors.New("is not a syslog facility such as local0 or daemon")
-		"is not a syslog facility such as local0 or daemon",
-	)
 	errNotAppName    = errors.New(
-		"is not 1 to 48 printable ASCII characters without a space, such as gitea",
+		"is not 1 to 48 printable ASCII characters without a space, such as gitea")
-	)
 	errSetTwice      = errors.New("set only one of them")
 	errNotWebhookURL = errors.New(
 		"is not an http or https URL without a user or a fragment, " +
@@ -431,135 +420,77 @@ var (
 		"is not a header name followed by : and the header's value, " +
 			"such as Authorization:Bearer <token>")
 	errControlCharacter = errors.New(
-		"holds a control character, such as the carriage return of a Windows line end",
+		"holds a control character, such as the carriage return of a Windows line end")
-	)
 	errNotAlertEvent = errors.New(
 		"is not ban, permanent_ban, waf_block, anomaly, reputation_hit, " +
 			"source_failure or file_error")
-	errNotNumberOrOff = errors.New(
+	errNotNumberOrOff = errors.New("is not a whole number above zero, such as 60, or off")
-		"is not a whole number above zero, such as 60, or off",
-	)
 	errNotUTF8        = errors.New("is not valid UTF-8")
 	errNotASN         = errors.New("is not an AS number such as AS64496")
 	errNotPercentItem = errors.New(
 		"is not a code, : and a percentage, such as AS64496:50 or cn:25")
-	errNotPercent = errors.New(
+	errNotPercent  = errors.New("is not a percentage, a whole number from 0 to 100")
-		"is not a percentage, a whole number from 0 to 100",
-	)
 	errListedTwice = errors.New("is listed twice")
 	errNotListURL  = errors.New(
 		"is not an http or https URL without a user or a fragment, " +
 			"such as https://www.spamhaus.org/drop/drop.txt")
 	errInBlocklistURLs = errors.New("is in SWWAF_BLOCKLIST_URLS too")
-	errNotAnHourOrMore = errors.New(
+	errNotAnHourOrMore = errors.New("is not a duration of 1h or more, such as 24h")
-		"is not a duration of 1h or more, such as 24h",
-	)
 	errNotAction       = errors.New(
 		"is not deny, limit:<percent> such as limit:25, or log")
-	errNotZone = errors.New(
+	errNotZone     = errors.New("is not a DNS zone such as dnsbl.dronebl.org")
-		"is not a DNS zone such as dnsbl.dronebl.org",
+	errZoneTooLong = errors.New("is longer than 189 characters, too long for the " +
-	)
+		"names IPv6 clients are asked about by")
-	errZoneTooLong = errors.New(
+	errNotResolver = errors.New("is not an IP address with an optional port, " +
-		"is longer than 189 characters, too long for the " +
+		"such as 192.0.2.53 or [2001:db8::53]:5353")
-			"names IPv6 clients are asked about by",
-	)
-	errNotResolver = errors.New(
-		"is not an IP address with an optional port, " +
-			"such as 192.0.2.53 or [2001:db8::53]:5353",
-	)
 	errNotLAPIURL = errors.New(
 		"is not an http or https URL without a user or a fragment, " +
 			"such as http://172.17.0.1:8080")
 	errNeedsLAPIKey  = errors.New("the engine answers no request without it")
-	errLAPIKeyUnused = errors.New(
+	errLAPIKeyUnused = errors.New("it is sent only to the engine at that URL")
-		"it is sent only to the engine at that URL",
-	)
 	errAnotherList   = errors.New(
 		"is in SWWAF_BLOCKLIST_URLS or is SWWAF_ASN_LIMIT_PERCENT_URL too")
 )
 
-// FromEnvironment reads the settings with lookupEnv, normally
+// FromEnvironment reads the settings through v, normally the viper
-// os.LookupEnv. A setting may instead be given as a file: the variable
+// NewViper returns, bound to the process's environment. A setting may
-// named by the setting's name with _FILE added names the file, which is
+// instead be given as a file: the variable named by the setting's name
-// read now (see lookup). A setting that is not set takes its default. A
+// with _FILE added names the file, which is read now (see lookup). A
-// setting that is set but invalid is an error that names it.
+// setting that is not set takes its default. A setting that is set but
+// invalid is an error that names it.
 //
 //nolint:funlen // one line for each setting, a list that grows with them
-func FromEnvironment(
+func FromEnvironment(v *viper.Viper) (*Config, error) {
-	lookupEnv func(string) (string, bool),
+	env := &environment{v: v, readFiles: true}
-) (*Config, error) {
-	env := &environment{lookupEnv: lookupEnv}
 	cfg := &Config{
 		ListenAddr:           env.address("SWWAF_LISTEN_ADDR"),
 		InstanceName:         env.instanceName(),
 		Observe:              env.observe("SWWAF_MODE", "enforce"),
-		IPv6GroupPrefix: env.ipv6GroupPrefix(
+		IPv6GroupPrefix:      env.ipv6GroupPrefix("SWWAF_IPV6_GROUP_PREFIX", "64"),
-			"SWWAF_IPV6_GROUP_PREFIX",
+		MaxTrackedClients:    env.numberNotOff("SWWAF_MAX_TRACKED_CLIENTS", "20000"),
-			"64",
-		),
-		MaxTrackedClients: env.numberNotOff(
-			"SWWAF_MAX_TRACKED_CLIENTS",
-			"20000",
-		),
 		AllowNets:            env.netblocks("SWWAF_ALLOW_NETS", ""),
-		RateLimitExemptNets: env.netblocks(
+		RateLimitExemptNets:  env.netblocks("SWWAF_RATE_LIMIT_EXEMPT_NETS", ""),
-			"SWWAF_RATE_LIMIT_EXEMPT_NETS",
-			"",
-		),
 		DenyNets:             env.netblocks("SWWAF_DENY_NETS", ""),
-		RateLimitPerMinute: env.count(
+		RateLimitPerMinute:   env.count("SWWAF_RATE_LIMIT_PER_MINUTE", "120"),
-			"SWWAF_RATE_LIMIT_PER_MINUTE",
-			"120",
-		),
 		RateLimitPerHour:     env.count("SWWAF_RATE_LIMIT_PER_HOUR", "1500"),
 		RateLimitPerDay:      env.count("SWWAF_RATE_LIMIT_PER_DAY", "6000"),
-		RateLimitExemptPaths: env.pathPrefixes(
+		RateLimitExemptPaths: env.pathPrefixes("SWWAF_RATE_LIMIT_EXEMPT_PATHS", ""),
-			"SWWAF_RATE_LIMIT_EXEMPT_PATHS",
+		BytesLimitPerMinute:  env.size("SWWAF_BYTES_LIMIT_PER_MINUTE", "off"),
-			"",
-		),
-		BytesLimitPerMinute: env.size(
-			"SWWAF_BYTES_LIMIT_PER_MINUTE",
-			"off",
-		),
 		BytesLimitPerHour:    env.size("SWWAF_BYTES_LIMIT_PER_HOUR", "50G"),
 		BytesLimitPerDay:     env.size("SWWAF_BYTES_LIMIT_PER_DAY", "100G"),
 		BytesCount:           env.bytesCount("SWWAF_BYTES_COUNT", "both"),
-		LookupSource: env.lookupSource(
+		LookupSource:         env.lookupSource("SWWAF_LOOKUP_SOURCE", "geojs"),
-			"SWWAF_LOOKUP_SOURCE",
-			"geojs",
-		),
 		LookupDBPath:         env.value("SWWAF_LOOKUP_DB_PATH", ""),
-		LookupTimeout: env.durationNotOff(
+		LookupTimeout:        env.durationNotOff("SWWAF_LOOKUP_TIMEOUT", "800ms"),
-			"SWWAF_LOOKUP_TIMEOUT",
+		AddLookupHeaders:     env.boolean("SWWAF_ADD_LOOKUP_HEADERS", "false"),
-			"800ms",
-		),
-		AddLookupHeaders: env.boolean(
-			"SWWAF_ADD_LOOKUP_HEADERS",
-			"false",
-		),
 		DeniedCountries:      env.countries("SWWAF_DENIED_COUNTRIES", ""),
 		ExclusivelyAllowedCountries: env.countries(
 			"SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES", ""),
-		ASNLimitPercent: env.percents(
+		ASNLimitPercent:      env.percents("SWWAF_ASN_LIMIT_PERCENT", ParseASN),
-			"SWWAF_ASN_LIMIT_PERCENT",
+		CountryLimitPercent:  env.percents("SWWAF_COUNTRY_LIMIT_PERCENT", parseCountry),
-			ParseASN,
+		ASNBytesPercent:      env.percents("SWWAF_ASN_BYTES_PERCENT", ParseASN),
-		),
+		CountryBytesPercent:  env.percents("SWWAF_COUNTRY_BYTES_PERCENT", parseCountry),
-		CountryLimitPercent: env.percents(
+		UnknownLimitPercent:  env.percent("SWWAF_UNKNOWN_LIMIT_PERCENT", "100"),
-			"SWWAF_COUNTRY_LIMIT_PERCENT",
-			parseCountry,
-		),
-		ASNBytesPercent: env.percents(
-			"SWWAF_ASN_BYTES_PERCENT",
-			ParseASN,
-		),
-		CountryBytesPercent: env.percents(
-			"SWWAF_COUNTRY_BYTES_PERCENT",
-			parseCountry,
-		),
-		UnknownLimitPercent: env.percent(
-			"SWWAF_UNKNOWN_LIMIT_PERCENT",
-			"100",
-		),
 		ASNLimitPercentURL:   env.listURL("SWWAF_ASN_LIMIT_PERCENT_URL"),
 		BlocklistURLs:        env.listURLs("SWWAF_BLOCKLIST_URLS"),
 		BlocklistRefresh:     env.refresh("SWWAF_BLOCKLIST_REFRESH", "24h"),
@@ -567,78 +498,32 @@ func FromEnvironment(
 		DNSBLResolver:        env.resolver("SWWAF_DNSBL_RESOLVER"),
 		AbuseIPDBKey:         env.secret("SWWAF_ABUSEIPDB_KEY"),
 		AbuseIPDBMinScore:    env.percent("SWWAF_ABUSEIPDB_MIN_SCORE", "75"),
-		AbuseIPDBDailyBudget: env.numberNotOff(
+		AbuseIPDBDailyBudget: env.numberNotOff("SWWAF_ABUSEIPDB_DAILY_BUDGET", "900"),
-			"SWWAF_ABUSEIPDB_DAILY_BUDGET",
+		ReputationCacheTTL:   env.durationNotOff("SWWAF_REPUTATION_CACHE_TTL", "24h"),
-			"900",
+		ReputationTimeout:    env.durationNotOff("SWWAF_REPUTATION_TIMEOUT", "2s"),
-		),
+		CrowdSecDecisionsURL: env.crowdSecDecisionsURL("SWWAF_CROWDSEC_LAPI_URL"),
-		ReputationCacheTTL: env.durationNotOff(
-			"SWWAF_REPUTATION_CACHE_TTL",
-			"24h",
-		),
-		ReputationTimeout: env.durationNotOff(
-			"SWWAF_REPUTATION_TIMEOUT",
-			"2s",
-		),
-		CrowdSecDecisionsURL: env.crowdSecDecisionsURL(
-			"SWWAF_CROWDSEC_LAPI_URL",
-		),
 		CrowdSecKey:          env.secret("SWWAF_CROWDSEC_LAPI_KEY"),
 		BanResponse:          env.banResponse("SWWAF_BAN_RESPONSE", "403"),
-		LimitBanDuration: env.durationNotOff(
+		LimitBanDuration:     env.durationNotOff("SWWAF_LIMIT_BAN_DURATION", "1h"),
-			"SWWAF_LIMIT_BAN_DURATION",
+		LimitBanRepeatWindow: env.durationNotOff("SWWAF_LIMIT_BAN_REPEAT_WINDOW", "24h"),
-			"1h",
+		MaxBanDuration:       env.durationNotOff("SWWAF_MAX_BAN_DURATION", "7d"),
-		),
+		AttackBanDuration:    env.durationNotOff("SWWAF_ATTACK_BAN_DURATION", "7d"),
-		LimitBanRepeatWindow: env.durationNotOff(
-			"SWWAF_LIMIT_BAN_REPEAT_WINDOW",
-			"24h",
-		),
-		MaxBanDuration: env.durationNotOff(
-			"SWWAF_MAX_BAN_DURATION",
-			"7d",
-		),
-		AttackBanDuration: env.durationNotOff(
-			"SWWAF_ATTACK_BAN_DURATION",
-			"7d",
-		),
 		MaxBans:              env.numberNotOff("SWWAF_MAX_BANS", "5000"),
-		BanScopeV4Prefix: env.v4Prefix(
+		BanScopeV4Prefix:     env.v4Prefix("SWWAF_BAN_SCOPE_V4_PREFIX", "32"),
-			"SWWAF_BAN_SCOPE_V4_PREFIX",
+		StateDir:             env.absolutePath("SWWAF_STATE_DIR", "/var/lib/smallwebwaf"),
-			"32",
+		StateWriteDelay:      env.durationNotOff("SWWAF_STATE_WRITE_DELAY", "10s"),
-		),
+		StateCounterInterval: env.durationNotOff("SWWAF_STATE_COUNTER_INTERVAL", "15m"),
-		StateDir: env.absolutePath(
+		LogRequestHeaders: env.headerNames("SWWAF_LOG_REQUEST_HEADERS",
-			"SWWAF_STATE_DIR",
+			"accept,accept-language,accept-encoding,content-type,origin,range"),
-			"/var/lib/smallwebwaf",
-		),
-		StateWriteDelay: env.durationNotOff(
-			"SWWAF_STATE_WRITE_DELAY",
-			"10s",
-		),
-		StateCounterInterval: env.durationNotOff(
-			"SWWAF_STATE_COUNTER_INTERVAL",
-			"15m",
-		),
-		LogRequestHeaders: env.headerNames(
-			"SWWAF_LOG_REQUEST_HEADERS",
-			"accept,accept-language,accept-encoding,content-type,origin,range",
-		),
 		LogLevel:            env.logLevel("SWWAF_LOG_LEVEL", "info"),
 		AdminToken:          env.token("SWWAF_ADMIN_TOKEN"),
 		MetricsToken:        env.token("SWWAF_METRICS_TOKEN"),
 		MetricsTopN:         env.numberNotOff("SWWAF_METRICS_TOP_N", "50"),
-		RulesDir: env.value(
+		RulesDir:            env.value("SWWAF_RULES_DIR", "/etc/smallwebwaf/rules.d"),
-			"SWWAF_RULES_DIR",
-			"/etc/smallwebwaf/rules.d",
-		),
 		RulesEnabled:        env.boolean("SWWAF_RULES_ENABLED", "true"),
 		WAFMode:             env.wafMode("SWWAF_WAF_MODE", WAFModeBlock),
-		WAFParanoiaLevel: env.paranoiaLevel(
+		WAFParanoiaLevel:    env.paranoiaLevel("SWWAF_WAF_PARANOIA_LEVEL", "1"),
-			"SWWAF_WAF_PARANOIA_LEVEL",
+		WAFAnomalyThreshold: env.numberOrOff("SWWAF_WAF_ANOMALY_THRESHOLD", "5"),
-			"1",
-		),
-		WAFAnomalyThreshold: env.numberOrOff(
-			"SWWAF_WAF_ANOMALY_THRESHOLD",
-			"5",
-		),
 		WAFDisabledRules: env.ruleIDs("SWWAF_WAF_DISABLED_RULES",
 			"920340,920420,920440,920640,930130,930140"),
 		WAFExemptPaths:       env.pathPrefixes("SWWAF_WAF_EXEMPT_PATHS", ""),
@@ -646,46 +531,25 @@ func FromEnvironment(
 		TrapPaths:            env.trapPaths("SWWAF_TRAP_PATHS"),
 		ErrorBurstThreshold:  env.count("SWWAF_ERROR_BURST_THRESHOLD", "30"),
 		LogRemoteURL:         env.logRemoteURL("SWWAF_LOG_REMOTE_URL"),
-		LogRemoteTLSCAs: env.certificates(
+		LogRemoteTLSCAs:      env.certificates("SWWAF_LOG_REMOTE_TLS_CA_FILE"),
-			"SWWAF_LOG_REMOTE_TLS_CA_FILE",
+		LogRemoteBuffer:      env.numberNotOff("SWWAF_LOG_REMOTE_BUFFER", "10000"),
-		),
+		LogRemoteFacility:    env.facility("SWWAF_LOG_REMOTE_FACILITY", "local0"),
-		LogRemoteBuffer: env.numberNotOff(
-			"SWWAF_LOG_REMOTE_BUFFER",
-			"10000",
-		),
-		LogRemoteFacility: env.facility(
-			"SWWAF_LOG_REMOTE_FACILITY",
-			"local0",
-		),
 		AlertWebhookURL:      env.webhookURL("SWWAF_ALERT_WEBHOOK_URL"),
-		AlertWebhookHeaders: env.webhookHeaders(
+		AlertWebhookHeaders:  env.webhookHeaders("SWWAF_ALERT_WEBHOOK_HEADERS"),
-			"SWWAF_ALERT_WEBHOOK_HEADERS",
+		AlertSlackWebhookURL: env.webhookURL("SWWAF_ALERT_SLACK_WEBHOOK_URL"),
-		),
-		AlertSlackWebhookURL: env.webhookURL(
-			"SWWAF_ALERT_SLACK_WEBHOOK_URL",
-		),
 		AlertNtfyURL:         env.webhookURL("SWWAF_ALERT_NTFY_URL"),
 		AlertNtfyToken:       env.secret("SWWAF_ALERT_NTFY_TOKEN"),
 		AlertEvents: env.alertEvents("SWWAF_ALERT_EVENTS",
 			strings.Join(alerts.Events(), ",")),
 		AlertCooldown:      env.duration("SWWAF_ALERT_COOLDOWN", "15m"),
-		AlertMaxPerHour: env.numberOrOff(
+		AlertMaxPerHour:    env.numberOrOff("SWWAF_ALERT_MAX_PER_HOUR", "60"),
-			"SWWAF_ALERT_MAX_PER_HOUR",
-			"60",
-		),
 		AnomalyClient:      env.thresholds("SWWAF_ANOMALY_CLIENT_"),
 		AnomalyNet:         env.thresholds("SWWAF_ANOMALY_NET_"),
 		AnomalyASN:         env.thresholds("SWWAF_ANOMALY_ASN_"),
 		AnomalyTotal:       env.thresholds("SWWAF_ANOMALY_TOTAL_"),
 		AnomalyWatch:       env.thresholds("SWWAF_WATCH_"),
-		AnomalyNetV4Prefix: env.v4Prefix(
+		AnomalyNetV4Prefix: env.v4Prefix("SWWAF_ANOMALY_NET_V4_PREFIX", "24"),
-			"SWWAF_ANOMALY_NET_V4_PREFIX",
+		AnomalyNetV6Prefix: env.v6Prefix("SWWAF_ANOMALY_NET_V6_PREFIX", "48"),
-			"24",
-		),
-		AnomalyNetV6Prefix: env.v6Prefix(
-			"SWWAF_ANOMALY_NET_V6_PREFIX",
-			"48",
-		),
 		WatchNets:          env.namedNetblocks("SWWAF_WATCH_NETS"),
 	}
 
@@ -714,8 +578,8 @@ func FromEnvironment(
 // Command reads only SMALLWEBWAF_COMMAND, the command the image runs and its
 // health check checks: rproxy when it is unset or empty, or servewaf. It cannot
 // be given as a file. Any other value is an error that names the setting.
-func Command(lookupEnv func(string) (string, bool)) (string, error) {
+func Command(v *viper.Viper) (string, error) {
-	command, _ := lookupEnv("SMALLWEBWAF_COMMAND")
+	command, _ := readSetting(v, "SMALLWEBWAF_COMMAND")
 
 	switch command {
 	case "", "rproxy":
@@ -723,21 +587,15 @@ func Command(lookupEnv func(string) (string, bool)) (string, error) {
 	case "servewaf":
 		return command, nil
 	default:
-		return "", fmt.Errorf(
+		return "", fmt.Errorf("SMALLWEBWAF_COMMAND: %q %w", command, errNotCommand)
-			"SMALLWEBWAF_COMMAND: %q %w",
-			command,
-			errNotCommand,
-		)
 	}
 }
 
 // ServeWAFListenAddr reads only SWWAF_LISTEN_ADDR, which may be given as a
 // file, as FromEnvironment does. The health check in servewaf's container needs
 // no other setting, so it reads no other, nor a file that another names.
-func ServeWAFListenAddr(
+func ServeWAFListenAddr(v *viper.Viper) (string, error) {
-	lookupEnv func(string) (string, bool),
+	env := &environment{v: v, readFiles: true}
-) (string, error) {
-	env := &environment{lookupEnv: lookupEnv}
 	listenAddr := env.address("SWWAF_LISTEN_ADDR")
 
 	return listenAddr, env.err
@@ -747,8 +605,8 @@ func ServeWAFListenAddr(
 // file, as FromEnvironment does, so that the line saying a setting is
 // invalid carries it too. A file that cannot be read gives the default
 // here, and FromEnvironment then stops the start over it.
-func InstanceName(lookupEnv func(string) (string, bool)) string {
+func InstanceName(v *viper.Viper) string {
-	env := &environment{lookupEnv: lookupEnv}
+	env := &environment{v: v, readFiles: true}
 
 	return env.instanceName()
 }
@@ -764,13 +622,26 @@ func (c *Config) LogValue() slog.Value {
 }
 
 // environment is where FromEnvironment reads the settings: it notes each
-// value for the log, and keeps the first error.
+// value for the log, and keeps the first error. It reads every setting
+// through v, the viper NewViper returns, and, unless readFiles is false,
+// honours each setting's _FILE form too.
 type environment struct {
-	lookupEnv func(string) (string, bool)
+	v         *viper.Viper
+	readFiles bool
 	settings  []slog.Attr
 	err       error
 }
 
+// readSetting returns a setting's value and whether it is set, reading it
+// through v.
+func readSetting(v *viper.Viper, name string) (string, bool) {
+	if !v.IsSet(name) {
+		return "", false
+	}
+
+	return v.GetString(name), true
+}
+
 // value returns a setting's value, or its default when it is not set,
 // and notes it for the log.
 func (e *environment) value(name, defaultValue string) string {
@@ -789,28 +660,27 @@ func (e *environment) value(name, defaultValue string) string {
 // names, less one newline at their end. It notes that file's path for the
 // log. Both variables set, or a file that cannot be read, is an error.
 func (e *environment) lookup(name string) (string, bool) {
-	value, set := e.lookupEnv(name)
+	value, set := readSetting(e.v, name)
+	if !e.readFiles {
+		return value, set
+	}
+
 	fileName := name + "_FILE"
 
-	path, inFile := e.lookupEnv(fileName)
+	path, inFile := readSetting(e.v, fileName)
 	if !inFile {
 		return value, set
 	}
 
 	if set {
-		e.check(
+		e.check(name, fmt.Errorf("is set, and so is %s; %w", fileName, errSetTwice))
-			name,
-			fmt.Errorf("is set, and so is %s; %w", fileName, errSetTwice),
-		)
 
 		return value, set
 	}
 
 	e.settings = append(e.settings, slog.String(fileName, path))
 
-	contents, err := os.ReadFile(
+	contents, err := os.ReadFile(path) //nolint:gosec // a file the admin names
-		path,
-	) //nolint:gosec // a file the admin names
 	if err != nil {
 		e.check(fileName, fmt.Errorf("cannot be read: %w", err))
 
@@ -1061,10 +931,7 @@ func (e *environment) zones(name string) []string {
 		logged[i] = MaskZoneKey(zone)
 	}
 
-	e.settings = append(
+	e.settings = append(e.settings, slog.String(name, strings.Join(logged, ",")))
-		e.settings,
-		slog.String(name, strings.Join(logged, ",")),
-	)
 
 	return zones
 }
@@ -1116,15 +983,10 @@ func (e *environment) checkLookupDBPath(cfg *Config) {
 	switch {
 	case cfg.LookupSource == fileSource && cfg.LookupDBPath == "":
 		e.check("SWWAF_LOOKUP_SOURCE", fmt.Errorf(
-			"is file while SWWAF_LOOKUP_DB_PATH is unset; %w",
+			"is file while SWWAF_LOOKUP_DB_PATH is unset; %w", errNeedsDBPath))
-			errNeedsDBPath,
-		))
 	case cfg.LookupSource != fileSource && cfg.LookupDBPath != "":
 		e.check("SWWAF_LOOKUP_DB_PATH", fmt.Errorf(
-			"is set while SWWAF_LOOKUP_SOURCE is %s; %w",
+			"is set while SWWAF_LOOKUP_SOURCE is %s; %w", cfg.LookupSource, errDBPathUnused))
-			cfg.LookupSource,
-			errDBPathUnused,
-		))
 	}
 }
 
@@ -1165,11 +1027,8 @@ func (e *environment) checkCountriesAndLookups(cfg *Config) {
 		{"SWWAF_ANOMALY_ASN_BYTES_PER_HOUR", cfg.AnomalyASN.BytesPerHour > 0},
 	} {
 		if setting.set {
-			e.check(
+			e.check(setting.name, fmt.Errorf("is set while SWWAF_LOOKUP_SOURCE is off; %w",
-				setting.name,
+				errNeedsLookups))
-				fmt.Errorf("is set while SWWAF_LOOKUP_SOURCE is off; %w",
-					errNeedsLookups),
-			)
 		}
 	}
 }
@@ -1192,21 +1051,14 @@ func (e *environment) checkCrowdSec(cfg *Config) {
 	switch {
 	case decisionsURL != "" && cfg.CrowdSecKey == "":
 		e.check("SWWAF_CROWDSEC_LAPI_URL", fmt.Errorf(
-			"is set while SWWAF_CROWDSEC_LAPI_KEY is unset; %w",
+			"is set while SWWAF_CROWDSEC_LAPI_KEY is unset; %w", errNeedsLAPIKey))
-			errNeedsLAPIKey,
-		))
 	case decisionsURL == "" && cfg.CrowdSecKey != "":
 		e.check("SWWAF_CROWDSEC_LAPI_KEY", fmt.Errorf(
-			"is set while SWWAF_CROWDSEC_LAPI_URL is unset; %w",
+			"is set while SWWAF_CROWDSEC_LAPI_URL is unset; %w", errLAPIKeyUnused))
-			errLAPIKeyUnused,
-		))
 	case decisionsURL != "" && (slices.Contains(cfg.BlocklistURLs, decisionsURL) ||
 		decisionsURL == cfg.ASNLimitPercentURL):
-		e.check(
+		e.check("SWWAF_CROWDSEC_LAPI_URL", fmt.Errorf("gives the decision list %q, which %w",
-			"SWWAF_CROWDSEC_LAPI_URL",
+			decisionsURL, errAnotherList))
-			fmt.Errorf("gives the decision list %q, which %w",
-				decisionsURL, errAnotherList),
-		)
 	}
 }
 
@@ -1221,9 +1073,7 @@ func (e *environment) headerNames(name, defaultValue string) []string {
 
 // durationNotOff reads a setting that is a duration and, unlike a
 // timeout, cannot be off.
-func (e *environment) durationNotOff(
+func (e *environment) durationNotOff(name, defaultValue string) time.Duration {
-	name, defaultValue string,
-) time.Duration {
 	duration, err := ParseDurationNotOff(e.value(name, defaultValue))
 	e.check(name, err)
 
@@ -1363,7 +1213,7 @@ func (e *environment) logRemoteURL(name string) *url.URL {
 // certificates. Unset or empty, it is nil. Its value names a file
 // already, so, unlike the other settings, it has no _FILE form.
 func (e *environment) certificates(name string) *x509.CertPool {
-	path, _ := e.lookupEnv(name)
+	path, _ := readSetting(e.v, name)
 	e.settings = append(e.settings, slog.String(name, path))
 
 	if path == "" {
@@ -1403,10 +1253,7 @@ func (e *environment) instanceName() string {
 
 	value := e.value("SWWAF_INSTANCE_NAME", hostname)
 	if !utf8.ValidString(value) {
-		e.check(
+		e.check("SWWAF_INSTANCE_NAME", fmt.Errorf("%q %w", value, errNotUTF8))
-			"SWWAF_INSTANCE_NAME",
-			fmt.Errorf("%q %w", value, errNotUTF8),
-		)
 	}
 
 	return value
@@ -1415,10 +1262,7 @@ func (e *environment) instanceName() string {
 // appName reads the setting that is the APP-NAME of the records the log
 // lines are sent in, by default the instance name. Its value is checked
 // when it is set, and, while lines are sent, when it is the instance name.
-func (e *environment) appName(
+func (e *environment) appName(name, instanceName string, sending bool) string {
-	name, instanceName string,
-	sending bool,
-) string {
 	value, set := e.lookup(name)
 	if !set {
 		value = instanceName
@@ -1431,14 +1275,8 @@ func (e *environment) appName(
 	case set:
 		e.check(name, fmt.Errorf("%q %w", value, errNotAppName))
 	case sending:
-		e.check(
+		e.check(name, fmt.Errorf("is unset, and SWWAF_INSTANCE_NAME %q, its default, %w",
-			name,
+			value, errNotAppName))
-			fmt.Errorf(
-				"is unset, and SWWAF_INSTANCE_NAME %q, its default, %w",
-				value,
-				errNotAppName,
-			),
-		)
 	}
 
 	return value
@@ -1447,16 +1285,11 @@ func (e *environment) appName(
 // checkInstanceNameForNtfy refuses an instance name that holds a control
 // character while ntfySet, SWWAF_ALERT_NTFY_URL being set: ntfy is sent
 // the instance name in a header, which cannot hold one.
-func (e *environment) checkInstanceNameForNtfy(
+func (e *environment) checkInstanceNameForNtfy(instanceName string, ntfySet bool) {
-	instanceName string,
-	ntfySet bool,
-) {
 	if ntfySet && strings.ContainsFunc(instanceName, unicode.IsControl) {
 		e.check("SWWAF_INSTANCE_NAME", fmt.Errorf(
 			"%q %w, and is sent to ntfy in a header while SWWAF_ALERT_NTFY_URL is set",
-			instanceName,
+			instanceName, errControlCharacter))
-			errControlCharacter,
-		))
 	}
 }
 
@@ -1776,10 +1609,7 @@ func parseNamedNetblocks(value string) ([]anomaly.NamedNetblock, error) {
 			return nil, fmt.Errorf("%q %w", name, errListedTwice)
 		}
 
-		named = append(
+		named = append(named, anomaly.NamedNetblock{Name: name, Netblock: netblock})
-			named,
-			anomaly.NamedNetblock{Name: name, Netblock: netblock},
-		)
 	}
 
 	return named, nil
@@ -2018,11 +1848,8 @@ func parseHeaderNames(value string) ([]string, error) {
 		header := strings.ToLower(item)
 		switch header {
 		case "host":
-			return nil, fmt.Errorf(
+			return nil, fmt.Errorf("%q %w; the request's host is the field host",
-				"%q %w; the request's host is the field host",
+				item, errHeaderTakenOut)
-				item,
-				errHeaderTakenOut,
-			)
 		case "transfer-encoding":
 			return nil, fmt.Errorf("%q %w", item, errHeaderTakenOut)
 		}
@@ -2059,11 +1886,9 @@ func parseUpstreamURL(value string) (*url.URL, error) {
 	}
 
 	onlySchemeAndHost := (upstream.Scheme == "http" || upstream.Scheme == "https") &&
-		upstream.Hostname() != "" && upstream.User == nil &&
+		upstream.Hostname() != "" && upstream.User == nil && upstream.Opaque == "" &&
-		upstream.Opaque == "" &&
 		(upstream.Path == "" || upstream.Path == "/") &&
-		upstream.RawQuery == "" &&
+		upstream.RawQuery == "" && upstream.Fragment == ""
-		upstream.Fragment == ""
 	if !onlySchemeAndHost {
 		return nil, fmt.Errorf("%q %w", value, errNotUpstreamURL)
 	}
@@ -2087,11 +1912,7 @@ func parseLogRemoteURL(value string) (*url.URL, error) {
 		return nil, fmt.Errorf("%q %w", value, errNotLogRemoteURL)
 	}
 
-	schemes := []string{
+	schemes := []string{remotelog.SchemeUDP, remotelog.SchemeTCP, remotelog.SchemeTLS}
-		remotelog.SchemeUDP,
-		remotelog.SchemeTCP,
-		remotelog.SchemeTLS,
-	}
 	port, err := strconv.ParseUint(remote.Port(), 10, 16)
 
 	onlySchemeHostAndPort := slices.Contains(schemes, remote.Scheme) &&
@@ -2154,9 +1975,7 @@ func isHTTPURL(u *url.URL) bool {
 
 	return (u.Scheme == "http" || u.Scheme == "https") && u.Hostname() != "" &&
 		(u.Port() == "" || (err == nil && port != 0)) &&
-		u.User == nil &&
+		u.User == nil && u.Opaque == "" && u.Fragment == ""
-		u.Opaque == "" &&
-		u.Fragment == ""
 }
 
 // isListURL reports whether value is a URL a list can be fetched from, as
@@ -2223,12 +2042,9 @@ func parseZones(value string) ([]string, error) {
 
 	for i, zone := range zones {
 		shown := MaskZoneKey(zone)
-		listedBefore := slices.ContainsFunc(
+		listedBefore := slices.ContainsFunc(zones[:i], func(earlier string) bool {
-			zones[:i],
-			func(earlier string) bool {
 			return strings.EqualFold(MaskZoneKey(earlier), shown)
-			},
+		})
-		)
 
 		switch {
 		case len(zone) > maxZoneLength:
@@ -2315,13 +2131,8 @@ func parseWebhookHeaders(value string) (http.Header, string, error) {
 		name, headerValue, found := strings.Cut(item, ":")
 		name = strings.TrimSpace(name)
 
-		if !found || !IsHeaderName(name) ||
+		if !found || !IsHeaderName(name) || strings.ContainsAny(headerValue, "\r\n\x00") {
-			strings.ContainsAny(headerValue, "\r\n\x00") {
+			return nil, "", fmt.Errorf("item %d %w", i+1, errNotWebhookHeader)
-			return nil, "", fmt.Errorf(
-				"item %d %w",
-				i+1,
-				errNotWebhookHeader,
-			)
 		}
 
 		headers.Add(name, strings.TrimSpace(headerValue))

internal/config/config_test.go

@@ -17,6 +17,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/anomaly"
 	"sneak.berlin/go/smallwebwaf/internal/config"
 )
@@ -217,18 +219,22 @@ const (
 // environment is a set of environment variables, for FromEnvironment.
 type environment map[string]string
 
-// lookupEnv reads one of the variables, as os.LookupEnv does.
+// viper returns a viper Set with each of the variables, as the viper
-func (e environment) lookupEnv(name string) (string, bool) {
+// NewViper returns one bound to a process's environment.
-	value, ok := e[name]
+func (e environment) viper() *viper.Viper {
+	v := viper.New()
+	for name, value := range e {
+		v.Set(name, value)
+	}
 
-	return value, ok
+	return v
 }
 
 // fromEnvironment reads the settings from env, which must be valid.
 func fromEnvironment(t *testing.T, env environment) *config.Config {
 	t.Helper()
 
-	cfg, err := config.FromEnvironment(env.lookupEnv)
+	cfg, err := config.FromEnvironment(env.viper())
 	if err != nil {
 		t.Fatalf("settings %v: %v", env, err)
 	}
@@ -455,7 +461,7 @@ func TestPathPrefixNotStartingWithSlashStopsTheStart(t *testing.T) {
 	t.Parallel()
 
 	_, err := config.FromEnvironment(
-		environment{rateLimitExemptPaths: "/favicon.ico,assets/"}.lookupEnv)
+		environment{rateLimitExemptPaths: "/favicon.ico,assets/"}.viper())
 
 	want := rateLimitExemptPaths + `: "assets/" is not a path prefix ` +
 		`starting with /, such as /assets/`
@@ -510,7 +516,7 @@ func TestInvalidTrapPathOrErrorBurstThresholdStopsTheStart(t *testing.T) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 
 			want := tc.name + ": " + tc.want
 			if err == nil || err.Error() != want {
@@ -636,7 +642,7 @@ func TestInvalidCoreRuleSetSettingStopsTheStart(t *testing.T) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 
 			want := tc.name + ": " + tc.want
 			if err == nil || err.Error() != want {
@@ -761,7 +767,7 @@ func TestInvalidRemoteLogSettingStopsTheStart(t *testing.T) {
 		{logRemoteAppName, ""}, {logRemoteAppName, "my app"},
 		{logRemoteAppName, "gitéa"}, {logRemoteAppName, strings.Repeat("a", 49)},
 	} {
-		_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+		_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 		if err == nil || !strings.HasPrefix(err.Error(), tc.name+": ") {
 			t.Errorf("%s=%q: error %v, want one naming it", tc.name, tc.value, err)
 		}
@@ -778,7 +784,7 @@ func TestRemoteLogCAFileWithoutCertificateStopsTheStart(t *testing.T) {
 		t.Fatalf("write %s: %v", caFile, err)
 	}
 
-	_, err = config.FromEnvironment(environment{logRemoteTLSCAFile: caFile}.lookupEnv)
+	_, err = config.FromEnvironment(environment{logRemoteTLSCAFile: caFile}.viper())
 
 	want := logRemoteTLSCAFile + `: "` + caFile + `" holds no PEM certificate`
 	if err == nil || err.Error() != want {
@@ -793,7 +799,7 @@ func TestInstanceNameNotAnAppNameStopsTheStartOnlyWhileSending(t *testing.T) {
 
 	sending := environment{logRemoteURL: remoteURL, instanceName: spaced}
 
-	_, err := config.FromEnvironment(sending.lookupEnv)
+	_, err := config.FromEnvironment(sending.viper())
 
 	want := logRemoteAppName + `: is unset, and ` + instanceName +
 		` "fsn1 app1", its default, is not 1 to 48 printable ASCII characters ` +
@@ -823,7 +829,7 @@ func TestAppNameSetStopsTheStartWhileSending(t *testing.T) {
 		logRemoteURL:     remoteURL,
 		instanceName:     instance,
 		logRemoteAppName: "my app",
-	}.lookupEnv)
+	}.viper())
 
 	want := logRemoteAppName + `: "my app" is not 1 to 48 printable ASCII ` +
 		`characters without a space, such as gitea`
@@ -954,7 +960,7 @@ func TestWebhookHeadersAreLoggedMaskedAndNeverShown(t *testing.T) {
 	// An item that is not a header is named by its place, not shown.
 	_, err := config.FromEnvironment(environment{
 		alertWebhookHeaders: "X-Team:ops," + secret,
-	}.lookupEnv)
+	}.viper())
 
 	want := alertWebhookHeaders + ": item 2 is not a header name followed by : " +
 		"and the header's value, such as Authorization:Bearer <token>"
@@ -991,7 +997,7 @@ func TestWebhookURLIsLoggedWithoutItsPathOrQueryAndNeverShown(t *testing.T) {
 		"ftp://hooks.example/services/" + secret,
 		"https://hooks.example/services/%zz" + secret,
 	} {
-		_, err := config.FromEnvironment(environment{alertWebhookURL: value}.lookupEnv)
+		_, err := config.FromEnvironment(environment{alertWebhookURL: value}.viper())
 
 		want := alertWebhookURL + ": is not an http or https URL without a user or " +
 			"a fragment, such as https://alerts.example/smallwebwaf"
@@ -1042,7 +1048,7 @@ func TestNtfyTokenWithAControlCharacterStopsTheStartWithoutShowingIt(t *testing.
 		"set":       {alertNtfyToken: token + "\r"},
 		"in a file": {alertNtfyToken + "_FILE": writeFile(t, token+"\r\n")},
 	} {
-		_, err := config.FromEnvironment(env.lookupEnv)
+		_, err := config.FromEnvironment(env.viper())
 
 		want := alertNtfyToken + ": holds a control character, such as the " +
 			"carriage return of a Windows line end"
@@ -1059,7 +1065,7 @@ func TestInstanceNameWithAControlCharacterStopsTheStartOnlyWithNtfySet(t *testin
 
 	_, err := config.FromEnvironment(environment{
 		instanceName: name, alertNtfyURL: "https://ntfy.example/smallwebwaf-alerts",
-	}.lookupEnv)
+	}.viper())
 
 	want := instanceName + `: "fsn1app1\r" holds a control character, such as the ` +
 		`carriage return of a Windows line end, and is sent to ntfy in a header ` +
@@ -1084,7 +1090,7 @@ func TestInstanceNameNotUTF8StopsTheStart(t *testing.T) {
 		"set":       {instanceName: latin1},
 		"in a file": {instanceName + "_FILE": writeFile(t, latin1+"\n")},
 	} {
-		_, err := config.FromEnvironment(env.lookupEnv)
+		_, err := config.FromEnvironment(env.viper())
 
 		want := instanceName + `: "caf\xe9" is not valid UTF-8`
 		if err == nil || err.Error() != want {
@@ -1099,7 +1105,7 @@ func TestCodeOnBothCountryListsStopsTheStart(t *testing.T) {
 	_, err := config.FromEnvironment(environment{
 		deniedCountries:  "cn,ru",
 		allowedCountries: "de,RU",
-	}.lookupEnv)
+	}.viper())
 	if err == nil {
 		t.Fatal("ru on both country lists was accepted")
 	}
@@ -1161,7 +1167,7 @@ func TestLookupDBPathGoesWithTheFileSourceAlone(t *testing.T) {
 			lookupDBPath + ": is set while " + lookupSource + " is off; only file reads it",
 		},
 	} {
-		_, err := config.FromEnvironment(tc.env.lookupEnv)
+		_, err := config.FromEnvironment(tc.env.viper())
 		if err == nil || err.Error() != tc.want {
 			t.Errorf("settings %v: error %v, want %s", tc.env, err, tc.want)
 		}
@@ -1191,7 +1197,7 @@ func TestSettingNeedingLookupsStopsTheStartWhileTheyAreOff(t *testing.T) {
 
 			_, err := config.FromEnvironment(environment{
 				lookupSource: off, name: value,
-			}.lookupEnv)
+			}.viper())
 			if err == nil || !strings.HasPrefix(err.Error(), name+": ") ||
 				!strings.Contains(err.Error(), lookupSource+" is off") {
 				t.Errorf("error %v, want one naming %s and %s", err, name, lookupSource)
@@ -1341,7 +1347,7 @@ func TestInvalidAnomalySettingStopsTheStartSayingWhatIsWrong(t *testing.T) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 
 			want := tc.name + ": " + tc.want
 			if err == nil || err.Error() != want {
@@ -1420,7 +1426,7 @@ func TestInvalidBiasedThresholdStopsTheStartSayingWhatIsWrong(t *testing.T) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 
 			want := tc.name + ": " + tc.want
 			if err == nil || err.Error() != want {
@@ -1517,7 +1523,7 @@ func TestInvalidReputationSettingStopsTheStartSayingWhatIsWrong(t *testing.T) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 
 			want := tc.name + ": " + tc.want
 			if err == nil || err.Error() != want {
@@ -1532,7 +1538,7 @@ func TestASNLimitPercentURLThatIsABlocklistStopsTheStart(t *testing.T) {
 
 	_, err := config.FromEnvironment(environment{
 		blocklistURLs: dropURL + "," + asnURL, asnLimitPercentURL: asnURL,
-	}.lookupEnv)
+	}.viper())
 
 	want := asnLimitPercentURL + `: "` + asnURL + `" is in SWWAF_BLOCKLIST_URLS too`
 	if err == nil || err.Error() != want {
@@ -1659,7 +1665,7 @@ func TestInvalidDNSBLSettingStopsTheStartSayingWhatIsWrong(t *testing.T) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 
 			want := tc.name + ": " + tc.want
 			if err == nil || err.Error() != want {
@@ -1727,7 +1733,7 @@ func TestDNSBLZoneKeyIsLoggedMaskedAndNeverShown(t *testing.T) {
 		{spamhaus + "," + otherZone, `"` + spamhausMasked + `" is listed twice`},
 		{spamhaus + ",,", "has an empty item in its list"},
 	} {
-		_, err := config.FromEnvironment(environment{dnsblZones: tc.value}.lookupEnv)
+		_, err := config.FromEnvironment(environment{dnsblZones: tc.value}.viper())
 
 		want := dnsblZones + ": " + tc.want
 		if err == nil || err.Error() != want {
@@ -1780,7 +1786,7 @@ func TestInvalidAbuseIPDBSettingStopsTheStartSayingWhatIsWrong(t *testing.T) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 
 			want := tc.name + ": " + tc.want
 			if err == nil || err.Error() != want {
@@ -1894,7 +1900,7 @@ func TestInvalidCrowdSecSettingStopsTheStartSayingWhatIsWrong(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(tc.env.lookupEnv)
+			_, err := config.FromEnvironment(tc.env.viper())
 			if err == nil || err.Error() != tc.want {
 				t.Errorf("error %v, want %s", err, tc.want)
 			}
@@ -2054,7 +2060,7 @@ func wantStartStopped(t *testing.T, invalid []struct{ name, value string }) {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{tc.name: tc.value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{tc.name: tc.value}.viper())
 			if err == nil {
 				t.Fatalf("%s=%q was accepted", tc.name, tc.value)
 			}
@@ -2079,7 +2085,7 @@ func TestHostOrTransferEncodingStopsTheStart(t *testing.T) {
 		t.Run(value, func(t *testing.T) {
 			t.Parallel()
 
-			_, err := config.FromEnvironment(environment{logRequestHeaders: value}.lookupEnv)
+			_, err := config.FromEnvironment(environment{logRequestHeaders: value}.viper())
 			if err == nil || err.Error() != logRequestHeaders+": "+want {
 				t.Errorf("error %v, want %s: %s", err, logRequestHeaders, want)
 			}
@@ -2096,7 +2102,7 @@ func TestShortTokenStopsTheStartWithoutShowingIt(t *testing.T) {
 			t.Run(name+"="+value, func(t *testing.T) {
 				t.Parallel()
 
-				_, err := config.FromEnvironment(environment{name: value}.lookupEnv)
+				_, err := config.FromEnvironment(environment{name: value}.viper())
 
 				want := name + ": is shorter than 32 characters"
 				if err == nil || err.Error() != want {
@@ -2152,7 +2158,7 @@ func TestSettingFromFileIsCheckedAsTheSettingItself(t *testing.T) {
 
 	_, err := config.FromEnvironment(environment{
 		bytesLimitPerMinute + "_FILE": writeFile(t, "lots\n"),
-	}.lookupEnv)
+	}.viper())
 
 	want := bytesLimitPerMinute + `: "lots" is not a size such as 512K, 100M or 5G, or off`
 	if err == nil || err.Error() != want {
@@ -2163,7 +2169,7 @@ func TestSettingFromFileIsCheckedAsTheSettingItself(t *testing.T) {
 		logRemoteURL:               remoteURL,
 		instanceName:               instance,
 		logRemoteAppName + "_FILE": writeFile(t, "my app\n"),
-	}.lookupEnv)
+	}.viper())
 
 	want = logRemoteAppName + `: "my app" is not 1 to 48 printable ASCII ` +
 		`characters without a space, such as gitea`
@@ -2178,7 +2184,7 @@ func TestSettingAndItsFileBothSetStopsTheStart(t *testing.T) {
 	_, err := config.FromEnvironment(environment{
 		metricsToken:           token,
 		metricsToken + "_FILE": writeFile(t, token),
-	}.lookupEnv)
+	}.viper())
 
 	want := metricsToken + ": is set, and so is " + metricsToken +
 		"_FILE; set only one of them"
@@ -2193,7 +2199,7 @@ func TestUnreadableSettingFileStopsTheStart(t *testing.T) {
 	dir := t.TempDir()
 
 	for _, path := range []string{filepath.Join(dir, "missing"), dir} {
-		_, err := config.FromEnvironment(environment{metricsToken + "_FILE": path}.lookupEnv)
+		_, err := config.FromEnvironment(environment{metricsToken + "_FILE": path}.viper())
 
 		want := metricsToken + "_FILE: cannot be read: "
 		if err == nil || !strings.HasPrefix(err.Error(), want) {

internal/config/rproxy.go

@@ -8,8 +8,9 @@ import (
 	"net/netip"
 	"net/url"
 	"strconv"
-	"strings"
 	"time"
+
+	"github.com/spf13/viper"
 )
 
 // RProxy is the settings of `smallwebwaf rproxy`. A size or time limit of zero
@@ -58,13 +59,13 @@ var (
 		"is not a whole number of milliseconds above zero, such as 60000, or off")
 )
 
-// RProxyFromEnvironment reads rproxy's settings with lookupEnv, normally
+// RProxyFromEnvironment reads rproxy's settings through v, normally the viper
-// os.LookupEnv. A setting that is not set takes its default, and
+// NewViper returns, bound to the process's environment. A setting that is not
-// SWRP_WAF_BACKEND, which has none, must be set. A setting that is set but
+// set takes its default, and SWRP_WAF_BACKEND, which has none, must be set. A
-// invalid is an error that names it. Since rproxy never touches disk, its
+// setting that is set but invalid is an error that names it. Since rproxy
-// settings have no _FILE form.
+// never touches disk, its settings have no _FILE form.
-func RProxyFromEnvironment(lookupEnv func(string) (string, bool)) (*RProxy, error) {
+func RProxyFromEnvironment(v *viper.Viper) (*RProxy, error) {
-	env := &environment{lookupEnv: withoutFileForms(lookupEnv)}
+	env := &environment{v: v, readFiles: false}
 	cfg := &RProxy{
 		ListenAddr:         env.address("SWRP_LISTEN_ADDR"),
 		UpstreamURL:        env.appURL("SWRP_UPSTREAM_URL", defaultUpstreamURL),
@@ -91,9 +92,9 @@ func RProxyFromEnvironment(lookupEnv func(string) (string, bool)) (*RProxy, erro
 // SWRP_UPSTREAM_URL. The health check in rproxy's container needs no other
 // setting, so it reads no other.
 func RProxyListenAddrAndUpstreamURL(
-	lookupEnv func(string) (string, bool),
+	v *viper.Viper,
 ) (string, *url.URL, error) {
-	env := &environment{lookupEnv: withoutFileForms(lookupEnv)}
+	env := &environment{v: v, readFiles: false}
 	listenAddr := env.address("SWRP_LISTEN_ADDR")
 	upstreamURL := env.appURL("SWRP_UPSTREAM_URL", defaultUpstreamURL)
 
@@ -104,20 +105,6 @@ func RProxyListenAddrAndUpstreamURL(
 	return listenAddr, upstreamURL, nil
 }
 
-// withoutFileForms returns lookupEnv finding no setting named with _FILE, since
-// rproxy never touches disk.
-func withoutFileForms(
-	lookupEnv func(string) (string, bool),
-) func(string) (string, bool) {
-	return func(name string) (string, bool) {
-		if strings.HasSuffix(name, "_FILE") {
-			return "", false
-		}
-
-		return lookupEnv(name)
-	}
-}
-
 // LogValue makes an RProxy log as each setting's name with the value it was
 // given, or its default.
 func (c *RProxy) LogValue() slog.Value {

internal/config/rproxy_test.go

@@ -9,6 +9,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/config"
 )
 
@@ -32,11 +34,12 @@ const (
 
 // rproxyConfig reads rproxy's settings from env.
 func rproxyConfig(env map[string]string) (*config.RProxy, error) {
-	return config.RProxyFromEnvironment(func(name string) (string, bool) {
+	v := viper.New()
-		value, ok := env[name]
+	for name, value := range env {
+		v.Set(name, value)
+	}
 
-		return value, ok
+	return config.RProxyFromEnvironment(v)
-	})
 }
 
 func TestRProxyDefaults(t *testing.T) {

internal/config/viper.go

@@ -0,0 +1,16 @@
+package config
+
+import "github.com/spf13/viper"
+
+// NewViper returns the viper that reads the settings: each setting's
+// environment variable, bound to its own name. Every setting of servewaf and
+// rproxy is read through it, and none is read with os.Getenv or os.LookupEnv
+// outside it. An environment variable that is set but empty is set, as one
+// that holds a value is, which viper does not take for granted.
+func NewViper() *viper.Viper {
+	v := viper.New()
+	v.AutomaticEnv()
+	v.AllowEmptyEnv(true)
+
+	return v
+}

internal/lookup/file.go

@@ -16,11 +16,6 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 )
 
-// FIXME: you can't call things just "File" - that's super vague.
-
-// FIXME: "lookup database" - in memory on disk?  you must not be so
-// ambiguous when describing things.
-
 // quietTime is how long the lookup database must go without a change
 // before it is read again, so that a file still being copied in is read
 // only once whole.
@@ -138,11 +133,8 @@ func (f *File) Watch(ctx context.Context) {
 	}
 
 	if err != nil {
-		f.params.ProcessLog.Error(
+		f.params.ProcessLog.Error("cannot watch the lookup database for replacements",
-			"cannot watch the lookup database for replacements",
+			"error", err.Error())
-			"error",
-			err.Error(),
-		)
 
 		return
 	}
@@ -202,10 +194,7 @@ func (f *File) readAgain() {
 		f.params.Alerts.Raise(alerts.Alert{
 			Event:  alerts.EventFileError,
 			Reason: kept,
-			Detail: map[string]any{
+			Detail: map[string]any{"file": f.params.Path, "error": err.Error()},
-				"file":  f.params.Path,
-				"error": err.Error(),
-			},
 		})
 		f.params.ProcessLog.Error(kept, "error", err.Error())
 
@@ -223,11 +212,7 @@ func (f *File) use(reader *maxminddb.Reader) {
 	f.lastRead = f.params.Now()
 	f.mu.Unlock()
 
-	f.params.ProcessLog.Info(
+	f.params.ProcessLog.Info("read the lookup database", "file", f.params.Path)
-		"read the lookup database",
-		"file",
-		f.params.Path,
-	)
 }
 
 // read reads the lookup database at path. The whole file is read into
@@ -236,19 +221,12 @@ func (f *File) use(reader *maxminddb.Reader) {
 func read(path string) (*maxminddb.Reader, error) {
 	data, err := os.ReadFile(path) //nolint:gosec // the file the admin names
 	if err != nil {
-		return nil, fmt.Errorf(
+		return nil, fmt.Errorf("SWWAF_LOOKUP_DB_PATH cannot be read: %w", err)
-			"SWWAF_LOOKUP_DB_PATH cannot be read: %w",
-			err,
-		)
 	}
 
 	reader, err := maxminddb.OpenBytes(data)
 	if err != nil {
-		return nil, fmt.Errorf(
+		return nil, fmt.Errorf("SWWAF_LOOKUP_DB_PATH %s is not a .mmdb file: %w", path, err)
-			"SWWAF_LOOKUP_DB_PATH %s is not a .mmdb file: %w",
-			path,
-			err,
-		)
 	}
 
 	return reader, nil

internal/requestlog/requestlog.go

@@ -19,51 +19,29 @@ const (
 	// ActionForward is a request servewaf allowed, which rproxy passes to the
 	// app.
 	ActionForward = "forward"
-
-	//FIXME: "too_large" doesn't tell a reader what that means.
-	//request_header_too_large does.  you must not use ambiguous terms.
-
 	// ActionTooLarge is a request over the header limits.
 	ActionTooLarge = "too_large"
-
 	// ActionRateLimited is a request refused because it took its client
 	// over a rate limit, which bans the client.
-
-	//FIXME: better would be "client_is_rate_limited"
 	ActionRateLimited = "rate_limited"
-
 	// ActionBanned is a request refused because a ban covers its client,
 	// or because it matched a ban rule, asked for a trap path or the
 	// CrowdSec decision list lists its client, each of which bans the
 	// client.
-
-	// FIXME: if I saw this, i would assume they are permanently banned.  is that
-	// true?  if not, there should be TemporarilyBanned and
-	// PermanentlyBanned
 	ActionBanned = "banned"
-
 	// ActionRuleBlocked is a request refused because it matched a block
 	// rule.
-
-	// FIXME: "blocked_by_block_rule"
 	ActionRuleBlocked = "rule_blocked"
-
 	// ActionWAFBlocked is a request refused because the Core Rule Set
 	// scored it at or over SWWAF_WAF_ANOMALY_THRESHOLD.
 	ActionWAFBlocked = "waf_blocked"
-
 	// ActionDenied is a request refused because its client is in
 	// SWWAF_DENY_NETS, in a blocklist while SWWAF_BLOCKLIST_ACTION is deny,
 	// or listed by a DNSBL zone, or scored a hit by AbuseIPDB, while
 	// SWWAF_REPUTATION_ACTION is deny.
 	ActionDenied = "denied"
-
 	// ActionCountryDenied is a request refused for its client's country.
 	ActionCountryDenied = "country_denied"
-
-	// FIXME: you have country_denied and denied.  why isn't it
-	// client_denied?  ALWAYS BE CONSISTENT AND UNAMBIGUOUS
-
 	// ActionAdmin is a request servewaf answered at one of its own endpoints,
 	// or a question about a path under /_smallwebwaf/.
 	ActionAdmin = "admin"
@@ -267,11 +245,7 @@ func FormatTime(t time.Time) string {
 
 // Milliseconds is d in milliseconds, to the microsecond.
 func Milliseconds(d time.Duration) float64 {
-	return float64(
+	return float64(d.Microseconds()) / float64(time.Millisecond/time.Microsecond)
-		d.Microseconds(),
-	) / float64(
-		time.Millisecond/time.Microsecond,
-	)
 }
 
 // NewProcessLogger returns the logger for the process's own messages:
@@ -279,25 +253,17 @@ func Milliseconds(d time.Duration) float64 {
 // as a request line's, and instanceName, SWWAF_INSTANCE_NAME, as instance.
 // It writes only the messages at level, SWWAF_LOG_LEVEL, or more severe;
 // the request lines Write writes are never held back.
-func NewProcessLogger(
+func NewProcessLogger(w io.Writer, instanceName string, level slog.Level) *slog.Logger {
-	w io.Writer,
-	instanceName string,
-	level slog.Level,
-) *slog.Logger {
 	handler := slog.NewJSONHandler(w, &slog.HandlerOptions{
 		Level: level,
 		ReplaceAttr: func(groups []string, attr slog.Attr) slog.Attr {
 			if attr.Key == slog.TimeKey && len(groups) == 0 {
-				return slog.String(
+				return slog.String(slog.TimeKey, FormatTime(attr.Value.Time()))
-					slog.TimeKey,
-					FormatTime(attr.Value.Time()),
-				)
 			}
 
 			return attr
 		},
 	})
 
-	return slog.New(handler).
+	return slog.New(handler).With("type", "process", "instance", instanceName)
-		With("type", "process", "instance", instanceName)
 }

internal/rproxy/limits_test.go

@@ -33,13 +33,9 @@ func announcedLength(size int) string {
 func TestServerHasTheFixedLimits(t *testing.T) {
 	t.Parallel()
 
-	cfg, err := config.RProxyFromEnvironment(func(name string) (string, bool) {
+	cfg, err := config.RProxyFromEnvironment(viperFrom(map[string]string{
-		if name == "SWRP_WAF_BACKEND" {
+		"SWRP_WAF_BACKEND": nowhere,
-			return nowhere, true
+	}))
-		}
-
-		return "", false
-	})
 	if err != nil {
 		t.Fatalf("settings: %v", err)
 	}

internal/rproxy/rproxy_test.go

@@ -18,6 +18,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/config"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 	"sneak.berlin/go/smallwebwaf/internal/rproxy"
@@ -341,6 +343,17 @@ func startServer(
 	return addr, out, server
 }
 
+// viperFrom returns a viper Set with each of settings, as the viper
+// config.NewViper returns one bound to a process's environment.
+func viperFrom(settings map[string]string) *viper.Viper {
+	v := viper.New()
+	for name, value := range settings {
+		v.Set(name, value)
+	}
+
+	return v
+}
+
 // startServerLogging is startServer with rproxy's request lines going to
 // requestLog and its process lines to processLog.
 func startServerLogging(
@@ -354,11 +367,7 @@ func startServerLogging(
 	}
 	maps.Copy(settings, env)
 
-	cfg, err := config.RProxyFromEnvironment(func(name string) (string, bool) {
+	cfg, err := config.RProxyFromEnvironment(viperFrom(settings))
-		value, ok := settings[name]
-
-		return value, ok
-	})
 	if err != nil {
 		t.Fatalf("settings %v: %v", settings, err)
 	}

internal/servewaf/proxy_test.go

@@ -15,6 +15,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/config"
 	"sneak.berlin/go/smallwebwaf/internal/lookup"
@@ -347,6 +349,17 @@ func serve(t *testing.T, server *servewaf.Server) {
 // at serveWAFAddr, with the settings in env on top of the defaults, and returns
 // where it listens. What it writes is dropped. SWRP_TIMEOUT_MS is a minute unless
 // env sets it, so that on a busy host SWRP_DEFAULT_DISPOSITION does not decide.
+// viperFrom returns a viper Set with each of settings, as the viper
+// config.NewViper returns one bound to a process's environment.
+func viperFrom(settings map[string]string) *viper.Viper {
+	v := viper.New()
+	for name, value := range settings {
+		v.Set(name, value)
+	}
+
+	return v
+}
+
 func startRProxy(
 	t *testing.T, serveWAFAddr, appURL string, env map[string]string,
 ) string {
@@ -359,11 +372,7 @@ func startRProxy(
 	}
 	maps.Copy(settings, env)
 
-	cfg, err := config.RProxyFromEnvironment(func(name string) (string, bool) {
+	cfg, err := config.RProxyFromEnvironment(viperFrom(settings))
-		value, ok := settings[name]
-
-		return value, ok
-	})
 	if err != nil {
 		t.Fatalf("settings %v: %v", settings, err)
 	}
@@ -423,11 +432,7 @@ func newServeWAFWith(
 
 	maps.Copy(settings, env)
 
-	cfg, err := config.FromEnvironment(func(name string) (string, bool) {
+	cfg, err := config.FromEnvironment(viperFrom(settings))
-		value, ok := settings[name]
-
-		return value, ok
-	})
 	if err != nil {
 		t.Fatalf("settings %v: %v", settings, err)
 	}

internal/smallwebwaf/healthcheck.go

@@ -10,6 +10,8 @@ import (
 	"net/url"
 	"time"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/config"
 	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 )
@@ -31,7 +33,7 @@ var errHealthEndpoint = errors.New("the health endpoint answered")
 // args are the arguments after `healthcheck`; it takes none, and given
 // one it names it on stderr and returns 1 without checking anything.
 func HealthCheck(
-	ctx context.Context, args []string, lookupEnv func(string) (string, bool),
+	ctx context.Context, args []string, v *viper.Viper,
 	stderr io.Writer,
 ) int {
 	if len(args) > 0 {
@@ -44,15 +46,15 @@ func HealthCheck(
 	ctx, cancel := context.WithTimeout(ctx, healthCheckTimeout)
 	defer cancel()
 
-	command, err := config.Command(lookupEnv)
+	command, err := config.Command(v)
 
 	switch {
 	case err != nil:
 		err = fmt.Errorf("invalid setting: %w", err)
 	case command == "servewaf":
-		err = checkServeWAF(ctx, lookupEnv)
+		err = checkServeWAF(ctx, v)
 	default:
-		err = checkRProxyAndApp(ctx, lookupEnv)
+		err = checkRProxyAndApp(ctx, v)
 	}
 
 	if err != nil {
@@ -65,8 +67,8 @@ func HealthCheck(
 }
 
 // checkServeWAF asks servewaf's health endpoint.
-func checkServeWAF(ctx context.Context, lookupEnv func(string) (string, bool)) error {
+func checkServeWAF(ctx context.Context, v *viper.Viper) error {
-	listenAddr, err := config.ServeWAFListenAddr(lookupEnv)
+	listenAddr, err := config.ServeWAFListenAddr(v)
 	if err != nil {
 		return fmt.Errorf("invalid setting: %w", err)
 	}
@@ -81,9 +83,9 @@ func checkServeWAF(ctx context.Context, lookupEnv func(string) (string, bool)) e
 
 // checkRProxyAndApp asks rproxy's health endpoint, and connects to the app.
 func checkRProxyAndApp(
-	ctx context.Context, lookupEnv func(string) (string, bool),
+	ctx context.Context, v *viper.Viper,
 ) error {
-	listenAddr, upstreamURL, err := config.RProxyListenAddrAndUpstreamURL(lookupEnv)
+	listenAddr, upstreamURL, err := config.RProxyListenAddrAndUpstreamURL(v)
 	if err != nil {
 		return fmt.Errorf("invalid setting: %w", err)
 	}

internal/smallwebwaf/healthcheck_test.go

@@ -145,11 +145,7 @@ func TestHealthCheckRefusesAnArgument(t *testing.T) {
 
 	var stderr bytes.Buffer
 
-	noSettings := func(string) (string, bool) {
+	got := smallwebwaf.HealthCheck(t.Context(), []string{"now"}, viperFrom(nil), &stderr)
-		return "", false
-	}
-
-	got := smallwebwaf.HealthCheck(t.Context(), []string{"now"}, noSettings, &stderr)
 
 	want := "smallwebwaf healthcheck: unexpected argument \"now\"\n"
 	if got != 1 || stderr.String() != want {
@@ -166,11 +162,7 @@ func wantHealthCheck(t *testing.T, env map[string]string, status int, message st
 
 	var stderr bytes.Buffer
 
-	got := smallwebwaf.HealthCheck(t.Context(), nil, func(name string) (string, bool) {
+	got := smallwebwaf.HealthCheck(t.Context(), nil, viperFrom(env), &stderr)
-		value, ok := env[name]
-
-		return value, ok
-	}, &stderr)
 
 	wrote := stderr.String()
 	if got != status || !strings.HasPrefix(wrote, message) ||

internal/smallwebwaf/rproxy.go

@@ -23,7 +23,7 @@ func RunRProxy(ctx context.Context, params Params) int {
 	hostname, _ := os.Hostname() // "" when the host has no name to give
 	processLog := requestlog.NewProcessLogger(params.Stdout, hostname, slog.LevelInfo)
 
-	cfg, err := config.RProxyFromEnvironment(params.LookupEnv)
+	cfg, err := config.RProxyFromEnvironment(params.Viper)
 	if err != nil {
 		processLog.Error("invalid setting", "error", err.Error())
 

internal/smallwebwaf/rproxy_test.go

@@ -43,11 +43,7 @@ const (
 func runRProxy(ctx context.Context, env map[string]string, out *output) int {
 	return smallwebwaf.RunRProxy(ctx, smallwebwaf.Params{
 		Version: testVersion,
-		LookupEnv: func(name string) (string, bool) {
+		Viper:   viperFrom(env),
-			value, ok := env[name]
-
-			return value, ok
-		},
 		Stdout:  out,
 	})
 }

internal/smallwebwaf/smallwebwaf.go

@@ -20,6 +20,8 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/config"
 	"sneak.berlin/go/smallwebwaf/internal/lookup"
@@ -58,8 +60,9 @@ commands:
 type Params struct {
 	// Version is the version of the binary, set when it is built.
 	Version string
-	// LookupEnv reads an environment variable, normally os.LookupEnv.
+	// Viper reads the settings, normally the viper config.NewViper returns
-	LookupEnv func(string) (string, bool)
+	// for the process's environment.
+	Viper *viper.Viper
 	// Stdout receives the request log and the process's own messages.
 	Stdout io.Writer
 }
@@ -78,7 +81,7 @@ func Main(version string) int {
 		syscall.SIGTERM, os.Interrupt)
 	defer stop()
 
-	params := Params{Version: version, LookupEnv: os.LookupEnv, Stdout: os.Stdout}
+	params := Params{Version: version, Viper: config.NewViper(), Stdout: os.Stdout}
 
 	switch args[0] {
 	case "rproxy":
@@ -86,7 +89,7 @@ func Main(version string) int {
 	case "servewaf":
 		return RunServeWAF(ctx, params)
 	case "healthcheck":
-		return HealthCheck(ctx, args[1:], os.LookupEnv, os.Stderr)
+		return HealthCheck(ctx, args[1:], params.Viper, os.Stderr)
 	default:
 		return printUsage(os.Stderr)
 	}
@@ -106,9 +109,9 @@ func RunServeWAF(ctx context.Context, params Params) int {
 	// Until the settings are read, the one message is an invalid setting's
 	// error, which every SWWAF_LOG_LEVEL lets through.
 	processLog := requestlog.NewProcessLogger(params.Stdout,
-		config.InstanceName(params.LookupEnv), slog.LevelError)
+		config.InstanceName(params.Viper), slog.LevelError)
 
-	cfg, err := config.FromEnvironment(params.LookupEnv)
+	cfg, err := config.FromEnvironment(params.Viper)
 	if err != nil {
 		processLog.Error("invalid setting", "error", err.Error())
 

internal/smallwebwaf/smallwebwaf_test.go

@@ -19,6 +19,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/spf13/viper"
+
 	"sneak.berlin/go/smallwebwaf/internal/lookup/lookuptest"
 	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 	"sneak.berlin/go/smallwebwaf/internal/smallwebwaf"
@@ -122,20 +124,29 @@ func (o *output) text() string {
 	return o.buf.String()
 }
 
+// viperFrom returns a viper Set with each of settings, as the viper
+// config.NewViper returns one bound to a process's environment.
+func viperFrom(settings map[string]string) *viper.Viper {
+	v := viper.New()
+	for name, value := range settings {
+		v.Set(name, value)
+	}
+
+	return v
+}
+
 // run runs `smallwebwaf servewaf` with the settings in env until ctx is done,
 // and returns its exit status. SWWAF_LOOKUP_SOURCE is off unless env sets it,
 // so that no test sends GeoJS its clients' addresses.
 func run(ctx context.Context, env map[string]string, out *output) int {
-	return smallwebwaf.RunServeWAF(ctx, smallwebwaf.Params{
+	v := viperFrom(env)
-		Version: testVersion,
+	if _, set := env["SWWAF_LOOKUP_SOURCE"]; !set {
-		LookupEnv: func(name string) (string, bool) {
+		v.Set("SWWAF_LOOKUP_SOURCE", "off")
-			value, ok := env[name]
-			if !ok && name == "SWWAF_LOOKUP_SOURCE" {
-				return "off", true
 	}
 
-			return value, ok
+	return smallwebwaf.RunServeWAF(ctx, smallwebwaf.Params{
-		},
+		Version: testVersion,
+		Viper:   v,
 		Stdout:  out,
 	})
 }

script/publish

@@ -1,51 +0,0 @@
-#!/bin/sh
-# script/publish: build the image on the Docker host and push it to the
-# registry under four tags: the UTC date (YYYY-MM-DD), the short commit
-# hash, the branch name and latest. The build is script/docker's, so the
-# tests and the linter run first. The host and the registry name are
-# environment variables with defaults, for running it against another.
-#
-# The working tree must be clean: the hash tag names a commit, and an
-# image built from uncommitted changes would carry a hash that does not
-# describe it.
-set -eu
-
-SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
-ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
-
-: "${DOCKER_HOST:=ssh://root@fsn1app1}"
-: "${PUBLISH_IMAGE:=git.eeqj.de/sneak/smallwebwaf}"
-export DOCKER_HOST
-
-main() {
-    cd "$ROOT"
-
-    if [ -n "$(git status --porcelain)" ]; then
-        echo "script/publish: the working tree is not clean; commit or stash first" >&2
-        exit 1
-    fi
-
-    date="$(date -u +%Y-%m-%d)"
-    hash="$(git rev-parse --short HEAD)"
-    branch="$(git rev-parse --abbrev-ref HEAD)"
-    if [ "$branch" = "HEAD" ]; then
-        echo "script/publish: detached HEAD; check out a branch first" >&2
-        exit 1
-    fi
-    # A tag is [A-Za-z0-9_.-]; a branch name such as feature/x is not.
-    branch="$(printf '%s' "$branch" | tr -c 'A-Za-z0-9_.-' '-')"
-
-    local_tag="$("$SCRIPT_DIR/projectname")"
-    "$SCRIPT_DIR/docker"
-
-    for tag in "$date" "$hash" "$branch" latest; do
-        docker tag "$local_tag" "$PUBLISH_IMAGE:$tag"
-    done
-    for tag in "$date" "$hash" "$branch" latest; do
-        docker push "$PUBLISH_IMAGE:$tag"
-    done
-
-    echo "pushed $PUBLISH_IMAGE with tags: $date $hash $branch latest"
-}
-
-main "$@"