Add example environment configuration and Docker Compose setup

- Introduced a new `.env.example` file to provide a template for environment variables used by the Scratchbox server.
- Added a `docker-compose.example.yml` file to facilitate easy deployment of the Scratchbox service with Docker.
- Updated `docker-entrypoint.sh` to enforce environment variable settings for server configuration.
- Removed the generation of a config key file from the workflow, simplifying the configuration process.
- Adjusted the README.md to reflect changes in configuration management and usage instructions.

internal/config/config.go

@@ -5,6 +5,7 @@ import (
 	"encoding/base64"
 	"errors"
 	"fmt"
+	"io/fs"
 	"net/netip"
 	"os"
 	"path/filepath"
@@ -31,8 +32,7 @@ const (
 	defaultRawCacheMaxEntries        = 32
 	defaultDataDir                   = "./data"
 	defaultCleanupInterval           = "1m"
-	defaultStorageEncryptionKey      = "vVPlqMfKa8OtD3x0RKp4rVCJ4QoScf5mWdgfg4f+5GU="
-	defaultEncryptionKeyFile         = "config.key"
+	dataDirEncryptionKeyFilename     = "metadata.key"
 	defaultUIRateLimitEnabled        = false
 	defaultAPIReadRateLimitEnabled   = false
 	defaultAPIWriteRateLimitEnabled  = true
@@ -44,6 +44,7 @@ const (
 	defaultAPIWriteRateLimitBurst    = 10
 	maxDefaultTTLLimit               = 24 * time.Hour
 	minCleanupInterval               = 10 * time.Second
+	envPrefix                        = "SCRATCHBOX_"
 )
 
 type Config struct {
@@ -88,7 +89,6 @@ type LimitsConfig struct {
 type StorageConfig struct {
 	DataDir               string        `yaml:"data_dir" comment:"Directory where scratch files and metadata are stored."`
 	CleanupInterval       string        `yaml:"cleanup_interval" comment:"How often expired scratches are deleted (minimum 10s)."`
-	EncryptionKeyFile     string        `yaml:"encryption_key_file" comment:"Path to a file containing a base64-encoded 32-byte AES key for at-rest encryption. Relative paths are resolved from the config file directory."`
 	CleanupIntervalParsed time.Duration `yaml:"-"`
 	EncryptionKeyBytes    []byte        `yaml:"-"`
 }
@@ -121,10 +121,17 @@ func Load(path string) (Config, error) {
 			return Config{}, fmt.Errorf("parse config yaml: %w", err)
 		}
 	}
-	if err := cfg.loadEncryptionKey(path); err != nil {
+	if err := cfg.Validate(); err != nil {
 		return Config{}, err
 	}
+	return cfg, nil
+}
 
+func LoadFromEnv() (Config, error) {
+	cfg := defaults()
+	if err := cfg.applyEnvOverrides(envPrefix); err != nil {
+		return Config{}, err
+	}
 	if err := cfg.Validate(); err != nil {
 		return Config{}, err
 	}
@@ -157,10 +164,8 @@ func defaults() Config {
 			RawCacheMaxEntries: defaultRawCacheMaxEntries,
 		},
 		Storage: StorageConfig{
-			DataDir:            defaultDataDir,
-			CleanupInterval:    defaultCleanupInterval,
-			EncryptionKeyFile:  defaultEncryptionKeyFile,
-			EncryptionKeyBytes: mustDecodeDefaultEncryptionKey(),
+			DataDir:         defaultDataDir,
+			CleanupInterval: defaultCleanupInterval,
 		},
 		Security: SecurityConfig{
 			AllowedIPs: []string{
@@ -276,12 +281,14 @@ func (c *Config) Validate() error {
 	if err := ensureWritableDir(c.Storage.DataDir); err != nil {
 		return fmt.Errorf("storage.data_dir not writable: %w", err)
 	}
-	if strings.TrimSpace(c.Storage.EncryptionKeyFile) == "" {
-		return errors.New("storage.encryption_key_file is required")
+	encKey, err := ensureEncryptionKeyInDataDir(c.Storage.DataDir)
+	if err != nil {
+		return fmt.Errorf("storage encryption key setup failed: %w", err)
 	}
-	if len(c.Storage.EncryptionKeyBytes) != 32 {
-		return fmt.Errorf("storage.encryption_key_file must decode to 32 bytes, got %d", len(c.Storage.EncryptionKeyBytes))
+	if len(encKey) != 32 {
+		return fmt.Errorf("storage encryption key must decode to 32 bytes, got %d", len(encKey))
 	}
+	c.Storage.EncryptionKeyBytes = encKey
 
 	prefixes, err := parseAllowedPrefixes(c.Security.AllowedIPs)
 	if err != nil {
@@ -419,27 +426,56 @@ func GenerateEncryptionKey() (string, error) {
 	return base64.StdEncoding.EncodeToString(raw), nil
 }
 
-func (c *Config) loadEncryptionKey(configPath string) error {
-	if configPath == "" {
-		return nil
-	}
-	keyPath := strings.TrimSpace(c.Storage.EncryptionKeyFile)
-	if keyPath == "" {
-		return errors.New("storage.encryption_key_file is required")
-	}
-	if !filepath.IsAbs(keyPath) {
-		keyPath = filepath.Join(filepath.Dir(configPath), keyPath)
-	}
+func ensureEncryptionKeyInDataDir(dataDir string) ([]byte, error) {
+	keyPath := filepath.Join(dataDir, dataDirEncryptionKeyFilename)
 	keyRaw, err := os.ReadFile(keyPath)
 	if err != nil {
-		return fmt.Errorf("read storage.encryption_key_file %q: %w", keyPath, err)
+		if !errors.Is(err, os.ErrNotExist) {
+			return nil, fmt.Errorf("read %q: %w", keyPath, err)
+		}
+		hasFiles, checkErr := dataDirContainsFiles(dataDir, keyPath)
+		if checkErr != nil {
+			return nil, fmt.Errorf("scan %q for existing files: %w", dataDir, checkErr)
+		}
+		if hasFiles {
+			return nil, fmt.Errorf("refusing to generate missing %q because %q contains files; restore the original key file to avoid data corruption", dataDirEncryptionKeyFilename, dataDir)
+		}
+		generated, genErr := GenerateEncryptionKey()
+		if genErr != nil {
+			return nil, fmt.Errorf("generate key: %w", genErr)
+		}
+		if writeErr := os.WriteFile(keyPath, []byte(generated+"\n"), 0o600); writeErr != nil {
+			return nil, fmt.Errorf("write %q: %w", keyPath, writeErr)
+		}
+		return decodeEncryptionKey(generated)
 	}
 	encKey, err := decodeEncryptionKey(strings.TrimSpace(string(keyRaw)))
 	if err != nil {
-		return fmt.Errorf("storage.encryption_key_file invalid: %w", err)
+		return nil, fmt.Errorf("%q invalid: %w", keyPath, err)
 	}
-	c.Storage.EncryptionKeyBytes = encKey
-	return nil
+	return encKey, nil
+}
+
+func dataDirContainsFiles(dataDir string, keyPath string) (bool, error) {
+	keyPath = filepath.Clean(keyPath)
+	foundFile := false
+	err := filepath.WalkDir(dataDir, func(path string, d fs.DirEntry, walkErr error) error {
+		if walkErr != nil {
+			return walkErr
+		}
+		if d.IsDir() {
+			return nil
+		}
+		if filepath.Clean(path) == keyPath {
+			return nil
+		}
+		foundFile = true
+		return fs.SkipAll
+	})
+	if err != nil && !errors.Is(err, fs.SkipAll) {
+		return false, err
+	}
+	return foundFile, nil
 }
 
 func decodeEncryptionKey(raw string) ([]byte, error) {
@@ -456,10 +492,150 @@ func decodeEncryptionKey(raw string) ([]byte, error) {
 	return encKey, nil
 }
 
-func mustDecodeDefaultEncryptionKey() []byte {
-	encKey, err := decodeEncryptionKey(defaultStorageEncryptionKey)
-	if err != nil {
-		panic(fmt.Sprintf("invalid built-in encryption key: %v", err))
+func (c *Config) applyEnvOverrides(prefix string) error {
+	if err := applyStringEnv(prefix+"SERVER_LISTEN_ADDR", &c.Server.ListenAddr); err != nil {
+		return err
 	}
-	return encKey
+	if err := applyStringEnv(prefix+"SERVER_READ_HEADER_TIMEOUT", &c.Server.ReadHeaderTimeout); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"SERVER_READ_TIMEOUT", &c.Server.ReadTimeout); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"SERVER_WRITE_TIMEOUT", &c.Server.WriteTimeout); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"SERVER_IDLE_TIMEOUT", &c.Server.IdleTimeout); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SERVER_MAX_HEADER_BYTES", &c.Server.MaxHeaderBytes); err != nil {
+		return err
+	}
+	if err := applyBoolEnv(prefix+"SERVER_ACCESS_LOG_ENABLED", &c.Server.AccessLog.Enabled); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"SERVER_ACCESS_LOG_FILE_PATH", &c.Server.AccessLog.FilePath); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"SERVER_ACCESS_LOG_MAX_SIZE", &c.Server.AccessLog.MaxSize); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SERVER_ACCESS_LOG_MAX_BACKUPS", &c.Server.AccessLog.MaxBackups); err != nil {
+		return err
+	}
+
+	if err := applyStringEnv(prefix+"LIMITS_MAX_UPLOAD_SIZE", &c.Limits.MaxUploadSize); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"LIMITS_DEFAULT_TTL", &c.Limits.DefaultTTL); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"LIMITS_RAW_CACHE_MAX_SIZE", &c.Limits.RawCacheMaxSize); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"LIMITS_RAW_CACHE_MAX_ENTRIES", &c.Limits.RawCacheMaxEntries); err != nil {
+		return err
+	}
+
+	if err := applyStringEnv(prefix+"STORAGE_DATA_DIR", &c.Storage.DataDir); err != nil {
+		return err
+	}
+	if err := applyStringEnv(prefix+"STORAGE_CLEANUP_INTERVAL", &c.Storage.CleanupInterval); err != nil {
+		return err
+	}
+
+	applyListEnv(prefix+"SECURITY_ALLOWED_IPS", &c.Security.AllowedIPs)
+	if err := applyBoolEnv(prefix+"SECURITY_TRUST_PROXY_HEADERS", &c.Security.TrustProxyHeaders); err != nil {
+		return err
+	}
+	applyListEnv(prefix+"SECURITY_TRUSTED_PROXY_IPS", &c.Security.TrustedProxyIPs)
+
+	if err := applyBoolEnv(prefix+"SECURITY_RATE_LIMIT_UI_ENABLED", &c.Security.RateLimitUI.Enabled); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SECURITY_RATE_LIMIT_UI_REQUESTS_PER_MINUTE", &c.Security.RateLimitUI.RequestsPerMinute); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SECURITY_RATE_LIMIT_UI_BURST", &c.Security.RateLimitUI.Burst); err != nil {
+		return err
+	}
+
+	if err := applyBoolEnv(prefix+"SECURITY_RATE_LIMIT_API_READ_ENABLED", &c.Security.RateLimitAPIRead.Enabled); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SECURITY_RATE_LIMIT_API_READ_REQUESTS_PER_MINUTE", &c.Security.RateLimitAPIRead.RequestsPerMinute); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SECURITY_RATE_LIMIT_API_READ_BURST", &c.Security.RateLimitAPIRead.Burst); err != nil {
+		return err
+	}
+
+	if err := applyBoolEnv(prefix+"SECURITY_RATE_LIMIT_API_WRITE_ENABLED", &c.Security.RateLimitAPIWrite.Enabled); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SECURITY_RATE_LIMIT_API_WRITE_REQUESTS_PER_MINUTE", &c.Security.RateLimitAPIWrite.RequestsPerMinute); err != nil {
+		return err
+	}
+	if err := applyIntEnv(prefix+"SECURITY_RATE_LIMIT_API_WRITE_BURST", &c.Security.RateLimitAPIWrite.Burst); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func applyStringEnv(name string, target *string) error {
+	value, ok := os.LookupEnv(name)
+	if !ok {
+		return nil
+	}
+	*target = strings.TrimSpace(value)
+	return nil
+}
+
+func applyBoolEnv(name string, target *bool) error {
+	value, ok := os.LookupEnv(name)
+	if !ok {
+		return nil
+	}
+	parsed, err := strconv.ParseBool(strings.TrimSpace(value))
+	if err != nil {
+		return fmt.Errorf("%s invalid bool: %w", name, err)
+	}
+	*target = parsed
+	return nil
+}
+
+func applyIntEnv(name string, target *int) error {
+	value, ok := os.LookupEnv(name)
+	if !ok {
+		return nil
+	}
+	parsed, err := strconv.Atoi(strings.TrimSpace(value))
+	if err != nil {
+		return fmt.Errorf("%s invalid int: %w", name, err)
+	}
+	*target = parsed
+	return nil
+}
+
+func applyListEnv(name string, target *[]string) {
+	value, ok := os.LookupEnv(name)
+	if !ok {
+		return
+	}
+	if strings.TrimSpace(value) == "" {
+		*target = nil
+		return
+	}
+
+	parts := strings.Split(value, ",")
+	out := make([]string, 0, len(parts))
+	for _, part := range parts {
+		item := strings.TrimSpace(part)
+		if item == "" {
+			continue
+		}
+		out = append(out, item)
+	}
+	*target = out
 }

internal/config/config_test.go

@@ -76,7 +76,6 @@ func TestLoadParsesConfiguredFields(t *testing.T) {
 	tmp := t.TempDir()
 	dataDir := filepath.Join(tmp, "store")
 	configPath := filepath.Join(tmp, "config.yaml")
-	keyPath := filepath.Join(tmp, "scratchbox.key")
 	content := `
 server:
   listen_addr: "127.0.0.1:9090"
@@ -98,7 +97,6 @@ limits:
 storage:
   data_dir: "` + dataDir + `"
   cleanup_interval: "45s"
-  encryption_key_file: "` + filepath.Base(keyPath) + `"
 security:
   allowed_ips:
     - "127.0.0.1"
@@ -122,9 +120,6 @@ security:
 	if err := os.WriteFile(configPath, []byte(content), 0o644); err != nil {
 		t.Fatalf("WriteFile() error = %v", err)
 	}
-	if err := os.WriteFile(keyPath, []byte("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=\n"), 0o600); err != nil {
-		t.Fatalf("WriteFile(key) error = %v", err)
-	}
 
 	cfg, err := Load(configPath)
 	if err != nil {
@@ -176,8 +171,8 @@ security:
 	if len(cfg.Storage.EncryptionKeyBytes) != 32 {
 		t.Fatalf("EncryptionKeyBytes length = %d, want 32", len(cfg.Storage.EncryptionKeyBytes))
 	}
-	if cfg.Storage.EncryptionKeyBytes[0] != 0 {
-		t.Fatalf("EncryptionKeyBytes[0] = %d, want 0", cfg.Storage.EncryptionKeyBytes[0])
+	if _, err := os.Stat(filepath.Join(dataDir, dataDirEncryptionKeyFilename)); err != nil {
+		t.Fatalf("expected data-dir key file to exist: %v", err)
 	}
 	if !cfg.Security.TrustProxyHeaders {
 		t.Fatalf("TrustProxyHeaders = false, want true")
@@ -362,20 +357,6 @@ func TestValidateRejectsInvalidValues(t *testing.T) {
 			},
 			wantErr: "storage.cleanup_interval",
 		},
-		{
-			name: "encryption key file required",
-			mutate: func(cfg *Config) {
-				cfg.Storage.EncryptionKeyFile = " "
-			},
-			wantErr: "storage.encryption_key_file is required",
-		},
-		{
-			name: "encryption key bytes invalid length",
-			mutate: func(cfg *Config) {
-				cfg.Storage.EncryptionKeyBytes = []byte("short")
-			},
-			wantErr: "storage.encryption_key_file must decode to 32 bytes",
-		},
 		{
 			name: "invalid ui rate limit rpm",
 			mutate: func(cfg *Config) {
@@ -447,20 +428,161 @@ storage:
 		t.Fatalf("WriteFile(valid config) error = %v", err)
 	}
 	_, err = Load(validConfigPath)
-	if err == nil || !strings.Contains(err.Error(), "read storage.encryption_key_file") {
-		t.Fatalf("Load() error = %v, want missing key file error", err)
+	if err != nil {
+		t.Fatalf("Load() error = %v, want nil", err)
 	}
 
-	keyPath := filepath.Join(tmp, "config.key")
+	keyPath := filepath.Join(tmp, "store", dataDirEncryptionKeyFilename)
 	if err := os.WriteFile(keyPath, []byte("not-base64"), 0o600); err != nil {
 		t.Fatalf("WriteFile(invalid key) error = %v", err)
 	}
 	_, err = Load(validConfigPath)
-	if err == nil || !strings.Contains(err.Error(), "storage.encryption_key_file invalid: invalid base64") {
+	if err == nil || !strings.Contains(err.Error(), "storage encryption key setup failed") {
 		t.Fatalf("Load() error = %v, want invalid key base64 error", err)
 	}
 }
 
+func TestLoadFailsWhenKeyMissingAndDataFilesExist(t *testing.T) {
+	t.Parallel()
+
+	tmp := t.TempDir()
+	dataDir := filepath.Join(tmp, "store")
+	scratchesDir := filepath.Join(dataDir, "scratches")
+	if err := os.MkdirAll(scratchesDir, 0o755); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(scratchesDir, "existing-scratch"), []byte("payload"), 0o600); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+
+	configPath := filepath.Join(tmp, "config.yaml")
+	configRaw := `
+storage:
+  data_dir: "` + dataDir + `"
+  cleanup_interval: "10s"
+`
+	if err := os.WriteFile(configPath, []byte(configRaw), 0o644); err != nil {
+		t.Fatalf("WriteFile(config) error = %v", err)
+	}
+
+	_, err := Load(configPath)
+	if err == nil || !strings.Contains(err.Error(), "refusing to generate missing") {
+		t.Fatalf("Load() error = %v, want missing-key safety error", err)
+	}
+}
+
+func TestLoadFromEnvParsesConfiguredFields(t *testing.T) {
+	dataDir := filepath.Join(t.TempDir(), "store")
+
+	t.Setenv("SCRATCHBOX_SERVER_LISTEN_ADDR", "127.0.0.1:19090")
+	t.Setenv("SCRATCHBOX_SERVER_READ_HEADER_TIMEOUT", "6s")
+	t.Setenv("SCRATCHBOX_SERVER_READ_TIMEOUT", "20s")
+	t.Setenv("SCRATCHBOX_SERVER_WRITE_TIMEOUT", "40s")
+	t.Setenv("SCRATCHBOX_SERVER_IDLE_TIMEOUT", "80s")
+	t.Setenv("SCRATCHBOX_SERVER_MAX_HEADER_BYTES", "2097152")
+	t.Setenv("SCRATCHBOX_SERVER_ACCESS_LOG_ENABLED", "false")
+	t.Setenv("SCRATCHBOX_SERVER_ACCESS_LOG_FILE_PATH", "/tmp/access.log")
+	t.Setenv("SCRATCHBOX_SERVER_ACCESS_LOG_MAX_SIZE", "4MiB")
+	t.Setenv("SCRATCHBOX_SERVER_ACCESS_LOG_MAX_BACKUPS", "8")
+
+	t.Setenv("SCRATCHBOX_LIMITS_MAX_UPLOAD_SIZE", "8MiB")
+	t.Setenv("SCRATCHBOX_LIMITS_DEFAULT_TTL", "30m")
+	t.Setenv("SCRATCHBOX_LIMITS_RAW_CACHE_MAX_SIZE", "64MiB")
+	t.Setenv("SCRATCHBOX_LIMITS_RAW_CACHE_MAX_ENTRIES", "16")
+
+	t.Setenv("SCRATCHBOX_STORAGE_DATA_DIR", dataDir)
+	t.Setenv("SCRATCHBOX_STORAGE_CLEANUP_INTERVAL", "15s")
+
+	t.Setenv("SCRATCHBOX_SECURITY_ALLOWED_IPS", "127.0.0.1,10.0.0.0/8")
+	t.Setenv("SCRATCHBOX_SECURITY_TRUST_PROXY_HEADERS", "true")
+	t.Setenv("SCRATCHBOX_SECURITY_TRUSTED_PROXY_IPS", "10.0.0.0/8")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_UI_ENABLED", "true")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_UI_REQUESTS_PER_MINUTE", "50")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_UI_BURST", "20")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_API_READ_ENABLED", "true")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_API_READ_REQUESTS_PER_MINUTE", "60")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_API_READ_BURST", "30")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_API_WRITE_ENABLED", "true")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_API_WRITE_REQUESTS_PER_MINUTE", "40")
+	t.Setenv("SCRATCHBOX_SECURITY_RATE_LIMIT_API_WRITE_BURST", "12")
+
+	cfg, err := LoadFromEnv()
+	if err != nil {
+		t.Fatalf("LoadFromEnv() error = %v", err)
+	}
+
+	if cfg.Server.ListenAddr != "127.0.0.1:19090" {
+		t.Fatalf("ListenAddr = %q, want %q", cfg.Server.ListenAddr, "127.0.0.1:19090")
+	}
+	if cfg.Server.ReadHeaderTimeoutDur != 6*time.Second {
+		t.Fatalf("ReadHeaderTimeoutDur = %s, want 6s", cfg.Server.ReadHeaderTimeoutDur)
+	}
+	if cfg.Server.ReadTimeoutDur != 20*time.Second {
+		t.Fatalf("ReadTimeoutDur = %s, want 20s", cfg.Server.ReadTimeoutDur)
+	}
+	if cfg.Server.WriteTimeoutDur != 40*time.Second {
+		t.Fatalf("WriteTimeoutDur = %s, want 40s", cfg.Server.WriteTimeoutDur)
+	}
+	if cfg.Server.IdleTimeoutDur != 80*time.Second {
+		t.Fatalf("IdleTimeoutDur = %s, want 80s", cfg.Server.IdleTimeoutDur)
+	}
+	if cfg.Server.MaxHeaderBytes != 2*1024*1024 {
+		t.Fatalf("MaxHeaderBytes = %d, want %d", cfg.Server.MaxHeaderBytes, 2*1024*1024)
+	}
+	if cfg.Server.AccessLog.Enabled {
+		t.Fatalf("AccessLog.Enabled = %v, want false", cfg.Server.AccessLog.Enabled)
+	}
+	if cfg.Limits.MaxUploadSizeBytes != 8*1024*1024 {
+		t.Fatalf("MaxUploadSizeBytes = %d, want %d", cfg.Limits.MaxUploadSizeBytes, int64(8*1024*1024))
+	}
+	if cfg.Limits.DefaultTTLDuration != 30*time.Minute {
+		t.Fatalf("DefaultTTLDuration = %s, want 30m", cfg.Limits.DefaultTTLDuration)
+	}
+	if cfg.Limits.RawCacheMaxBytes != 64*1024*1024 {
+		t.Fatalf("RawCacheMaxBytes = %d, want %d", cfg.Limits.RawCacheMaxBytes, int64(64*1024*1024))
+	}
+	if cfg.Limits.RawCacheMaxEntries != 16 {
+		t.Fatalf("RawCacheMaxEntries = %d, want 16", cfg.Limits.RawCacheMaxEntries)
+	}
+	if cfg.Storage.DataDir != dataDir {
+		t.Fatalf("DataDir = %q, want %q", cfg.Storage.DataDir, dataDir)
+	}
+	if cfg.Storage.CleanupIntervalParsed != 15*time.Second {
+		t.Fatalf("CleanupIntervalParsed = %s, want 15s", cfg.Storage.CleanupIntervalParsed)
+	}
+	if len(cfg.Storage.EncryptionKeyBytes) != 32 {
+		t.Fatalf("EncryptionKeyBytes length = %d, want 32", len(cfg.Storage.EncryptionKeyBytes))
+	}
+	if len(cfg.Security.AllowedPrefixes) != 2 {
+		t.Fatalf("AllowedPrefixes len = %d, want 2", len(cfg.Security.AllowedPrefixes))
+	}
+	if len(cfg.Security.TrustedProxyPrefixes) != 1 {
+		t.Fatalf("TrustedProxyPrefixes len = %d, want 1", len(cfg.Security.TrustedProxyPrefixes))
+	}
+	if !cfg.Security.TrustProxyHeaders {
+		t.Fatalf("TrustProxyHeaders = false, want true")
+	}
+	if cfg.Security.RateLimitUI.RequestsPerMinute != 50 || cfg.Security.RateLimitUI.Burst != 20 {
+		t.Fatalf("unexpected rate_limit_ui values: %+v", cfg.Security.RateLimitUI)
+	}
+	if cfg.Security.RateLimitAPIRead.RequestsPerMinute != 60 || cfg.Security.RateLimitAPIRead.Burst != 30 {
+		t.Fatalf("unexpected rate_limit_api_read values: %+v", cfg.Security.RateLimitAPIRead)
+	}
+	if cfg.Security.RateLimitAPIWrite.RequestsPerMinute != 40 || cfg.Security.RateLimitAPIWrite.Burst != 12 {
+		t.Fatalf("unexpected rate_limit_api_write values: %+v", cfg.Security.RateLimitAPIWrite)
+	}
+}
+
+func TestLoadFromEnvRejectsInvalidBool(t *testing.T) {
+	t.Setenv("SCRATCHBOX_STORAGE_DATA_DIR", filepath.Join(t.TempDir(), "store"))
+	t.Setenv("SCRATCHBOX_SERVER_ACCESS_LOG_ENABLED", "not-bool")
+
+	_, err := LoadFromEnv()
+	if err == nil || !strings.Contains(err.Error(), "SCRATCHBOX_SERVER_ACCESS_LOG_ENABLED invalid bool") {
+		t.Fatalf("LoadFromEnv() error = %v, want invalid bool env error", err)
+	}
+}
+
 func TestParseAllowedPrefixesTrimsAndParses(t *testing.T) {
 	t.Parallel()