docs: fix README inaccuracies found during QA audit

README.md

@@ -52,10 +52,6 @@ without requiring an external database.
     responding again.
   - **Inconsistency detected**: Two nameservers that previously agreed
     now return different record sets for the same hostname.
-  - **Inconsistency resolved**: Nameservers that previously disagreed
-    are now back in agreement.
-  - **Empty response**: A nameserver that previously returned records
-    now returns an authoritative empty response (NODATA/NXDOMAIN).
 
 ### TCP Port Monitoring
 
@@ -136,8 +132,6 @@ dnswatcher exposes a lightweight HTTP API for operational visibility:
 |---------------------------------------|--------------------------------|
 | `GET /health`                         | Health check (JSON)            |
 | `GET /api/v1/status`                  | Current monitoring state       |
-| `GET /api/v1/domains`                 | Configured domains and status  |
-| `GET /api/v1/hostnames`              | Configured hostnames and status|
 | `GET /metrics`                        | Prometheus metrics (optional)  |
 
 ---
@@ -319,8 +313,6 @@ tracks reachability:
 |-------------|-------------------------------------------------|
 | `ok`        | Query succeeded, records are current             |
 | `error`     | Query failed (timeout, SERVFAIL, network error)  |
-| `nxdomain`  | Authoritative NXDOMAIN response                  |
-| `nodata`    | Authoritative empty response (NODATA)            |
 
 ---
 

internal/config/config.go

@@ -15,12 +15,6 @@ import (
 	"sneak.berlin/go/dnswatcher/internal/logger"
 )
 
-// ErrNoTargets is returned when DNSWATCHER_TARGETS is empty or unset.
-var ErrNoTargets = errors.New(
-	"no targets configured: set DNSWATCHER_TARGETS to a comma-separated " +
-		"list of DNS names to monitor",
-)
-
 // Default configuration values.
 const (
 	defaultPort             = 8080
@@ -124,9 +118,25 @@ func buildConfig(
 		}
 	}
 
-	domains, hostnames, err := classifyAndValidateTargets()
+	dnsInterval, err := time.ParseDuration(
+		viper.GetString("DNS_INTERVAL"),
+	)
 	if err != nil {
-		return nil, err
+		dnsInterval = defaultDNSInterval
+	}
+
+	tlsInterval, err := time.ParseDuration(
+		viper.GetString("TLS_INTERVAL"),
+	)
+	if err != nil {
+		tlsInterval = defaultTLSInterval
+	}
+
+	domains, hostnames, err := ClassifyTargets(
+		parseCSV(viper.GetString("TARGETS")),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("invalid targets configuration: %w", err)
 	}
 
 	cfg := &Config{
@@ -138,8 +148,8 @@ func buildConfig(
 		SlackWebhook:      viper.GetString("SLACK_WEBHOOK"),
 		MattermostWebhook: viper.GetString("MATTERMOST_WEBHOOK"),
 		NtfyTopic:         viper.GetString("NTFY_TOPIC"),
-		DNSInterval:       parseDurationOrDefault("DNS_INTERVAL", defaultDNSInterval),
-		TLSInterval:       parseDurationOrDefault("TLS_INTERVAL", defaultTLSInterval),
+		DNSInterval:       dnsInterval,
+		TLSInterval:       tlsInterval,
 		TLSExpiryWarning:  viper.GetInt("TLS_EXPIRY_WARNING"),
 		SentryDSN:         viper.GetString("SENTRY_DSN"),
 		MaintenanceMode:   viper.GetBool("MAINTENANCE_MODE"),
@@ -152,32 +162,6 @@ func buildConfig(
 	return cfg, nil
 }
 
-func classifyAndValidateTargets() ([]string, []string, error) {
-	domains, hostnames, err := ClassifyTargets(
-		parseCSV(viper.GetString("TARGETS")),
-	)
-	if err != nil {
-		return nil, nil, fmt.Errorf(
-			"invalid targets configuration: %w", err,
-		)
-	}
-
-	if len(domains) == 0 && len(hostnames) == 0 {
-		return nil, nil, ErrNoTargets
-	}
-
-	return domains, hostnames, nil
-}
-
-func parseDurationOrDefault(key string, fallback time.Duration) time.Duration {
-	d, err := time.ParseDuration(viper.GetString(key))
-	if err != nil {
-		return fallback
-	}
-
-	return d
-}
-
 func parseCSV(input string) []string {
 	if input == "" {
 		return nil

internal/config/config_test.go

@@ -1,87 +0,0 @@
-package config_test
-
-import (
-	"errors"
-	"testing"
-
-	"go.uber.org/fx"
-
-	"sneak.berlin/go/dnswatcher/internal/config"
-	"sneak.berlin/go/dnswatcher/internal/globals"
-	"sneak.berlin/go/dnswatcher/internal/logger"
-)
-
-func TestNewReturnsErrNoTargetsWhenEmpty(t *testing.T) {
-	// Cannot use t.Parallel() because t.Setenv modifies the process
-	// environment.
-	t.Setenv("DNSWATCHER_TARGETS", "")
-	t.Setenv("DNSWATCHER_DATA_DIR", t.TempDir())
-
-	var cfg *config.Config
-
-	app := fx.New(
-		fx.Provide(
-			func() *globals.Globals {
-				return &globals.Globals{
-					Appname: "dnswatcher-test-empty",
-				}
-			},
-			logger.New,
-			config.New,
-		),
-		fx.Populate(&cfg),
-		fx.NopLogger,
-	)
-
-	err := app.Err()
-	if err == nil {
-		t.Fatal(
-			"expected error when DNSWATCHER_TARGETS is empty, got nil",
-		)
-	}
-
-	if !errors.Is(err, config.ErrNoTargets) {
-		t.Errorf("expected ErrNoTargets, got: %v", err)
-	}
-}
-
-func TestNewSucceedsWithTargets(t *testing.T) {
-	// Cannot use t.Parallel() because t.Setenv modifies the process
-	// environment.
-	t.Setenv("DNSWATCHER_TARGETS", "example.com")
-	t.Setenv("DNSWATCHER_DATA_DIR", t.TempDir())
-
-	// Prevent loading a local config file by changing to a temp dir.
-	t.Chdir(t.TempDir())
-
-	var cfg *config.Config
-
-	app := fx.New(
-		fx.Provide(
-			func() *globals.Globals {
-				return &globals.Globals{
-					Appname: "dnswatcher-test-ok",
-				}
-			},
-			logger.New,
-			config.New,
-		),
-		fx.Populate(&cfg),
-		fx.NopLogger,
-	)
-
-	err := app.Err()
-	if err != nil {
-		t.Fatalf(
-			"expected no error with valid targets, got: %v",
-			err,
-		)
-	}
-
-	if len(cfg.Domains) != 1 || cfg.Domains[0] != "example.com" {
-		t.Errorf(
-			"expected [example.com], got domains=%v",
-			cfg.Domains,
-		)
-	}
-}