diff --git a/conf/config.toml.example b/conf/config.example.toml
similarity index 75%
rename from conf/config.toml.example
rename to conf/config.example.toml
index 1b44279..6c1dc54 100644
--- a/conf/config.toml.example
+++ b/conf/config.example.toml
@@ -1,7 +1,9 @@
-[listen]
-pages = "tcp/:3000"
-caddy = "tcp/:3001"
-health = "tcp/:3002"
+# log-format = "datetime+message"
+
+# [listen]
+# pages = "tcp/:3000"
+# caddy = "tcp/:3001" # or "-" to disable
+# health = "tcp/:3002"
 
 # [[wildcard]]
 # domain = "codeberg.page"
@@ -9,11 +11,11 @@ health = "tcp/:3002"
 # index-repos = ["<user>.codeberg.page", "pages"]
 # fallback-proxy-to = "https://codeberg.page"
 
-[backend]
-type = "fs"
+# [backend]
+# type = "fs"
 
-[backend.fs]
-root = "data"
+# [backend.fs]
+# root = "./data"
 
 # [backend.s3]
 # endpoint = "play.min.io"
diff --git a/src/backend_s3.go b/src/backend_s3.go
index 69d157d..6d4dc45 100644
--- a/src/backend_s3.go
+++ b/src/backend_s3.go
@@ -39,32 +39,19 @@ type S3Backend struct {
 	siteCache *otter.Cache[string, *CachedManifest]
 }
 
-func defaultCacheConfig[K comparable, V any](
+func makeCacheOptions[K comparable, V any](
 	config CacheConfig,
-	maxAge time.Duration,
-	maxSize uint64,
 	weigher func(K, V) uint32,
-) (*otter.Options[K, V], error) {
-	var err error
-	if config.MaxAge != "" {
-		maxAge, err = time.ParseDuration(config.MaxAge)
-		if err != nil {
-			return nil, fmt.Errorf("max-age: %w", err)
-		}
-	}
-	if config.MaxSize != 0 {
-		maxSize = config.MaxSize
-	}
-
+) *otter.Options[K, V] {
 	options := &otter.Options[K, V]{}
-	if maxSize != 0 {
-		options.MaximumWeight = maxSize
+	if config.MaxSize != 0 {
+		options.MaximumWeight = config.MaxSize.Bytes()
 		options.Weigher = weigher
 	}
-	if maxAge != 0 {
-		options.ExpiryCalculator = otter.ExpiryWriting[K, V](maxAge)
+	if config.MaxAge != 0 {
+		options.ExpiryCalculator = otter.ExpiryWriting[K, V](time.Duration(config.MaxAge) * time.Second)
 	}
-	return options, nil
+	return options
 }
 
 func NewS3Backend(
@@ -102,28 +89,14 @@ func NewS3Backend(
 		}
 	}
 
-	blobCacheOptions, err := defaultCacheConfig(
-		config.Backend.S3.BlobCache,
-		0, 256*1048576,
-		func(key string, value *CachedBlob) uint32 { return uint32(len(value.blob)) })
+	blobCache, err := otter.New(makeCacheOptions(config.Backend.S3.BlobCache,
+		func(key string, value *CachedBlob) uint32 { return uint32(len(value.blob)) }))
 	if err != nil {
 		return nil, err
 	}
 
-	blobCache, err := otter.New(blobCacheOptions)
-	if err != nil {
-		return nil, err
-	}
-
-	siteCacheOptions, err := defaultCacheConfig(
-		config.Backend.S3.SiteCache,
-		60*time.Second, 16*1048576,
-		func(key string, value *CachedManifest) uint32 { return value.weight })
-	if err != nil {
-		return nil, err
-	}
-
-	siteCache, err := otter.New(siteCacheOptions)
+	siteCache, err := otter.New(makeCacheOptions(config.Backend.S3.SiteCache,
+		func(key string, value *CachedManifest) uint32 { return value.weight }))
 	if err != nil {
 		return nil, err
 	}
diff --git a/src/config.go b/src/config.go
index 892a250..ddd96a9 100644
--- a/src/config.go
+++ b/src/config.go
@@ -10,16 +10,16 @@ import (
 )
 
 type CacheConfig struct {
-	MaxSize uint64 `toml:"max-size"` // in bytes
-	MaxAge  string `toml:"max-age"`
+	MaxSize datasize.ByteSize `toml:"max-size"`
+	MaxAge  uint              `toml:"max-age"` // in seconds
 }
 
 type Config struct {
-	LogFormat string `toml:"log-format"`
+	LogFormat string `toml:"log-format" default:"datetime+message"`
 	Listen    struct {
-		Pages  string `toml:"pages"`
-		Caddy  string `toml:"caddy"`
-		Health string `toml:"health"`
+		Pages  string `toml:"pages" default:"tcp/:3000"`
+		Caddy  string `toml:"caddy" default:"tcp/:3001"`
+		Health string `toml:"health" default:"tcp/:3002"`
 	} `toml:"listen"`
 	Wildcard []struct {
 		Domain          string   `toml:"domain"`
@@ -28,9 +28,9 @@ type Config struct {
 		FallbackProxyTo string   `toml:"fallback-proxy-to"`
 	} `toml:"wildcard"`
 	Backend struct {
-		Type string `toml:"type"`
+		Type string `toml:"type" default:"fs"`
 		FS   struct {
-			Root string `toml:"root"`
+			Root string `toml:"root" default:"./data"`
 		} `toml:"fs"`
 		S3 struct {
 			Endpoint        string      `toml:"endpoint"`
@@ -39,8 +39,8 @@ type Config struct {
 			SecretAccessKey string      `toml:"secret-access-key"`
 			Region          string      `toml:"region"`
 			Bucket          string      `toml:"bucket"`
-			BlobCache       CacheConfig `toml:"blob-cache"`
-			SiteCache       CacheConfig `toml:"site-cache"`
+			BlobCache       CacheConfig `toml:"blob-cache" default:"{\"MaxSize\":\"256MB\"}"`
+			SiteCache       CacheConfig `toml:"site-cache" default:"{\"MaxAge\":60,\"MaxSize\":\"16MB\"}"`
 		}
 	} `toml:"backend"`
 	Limits struct {
diff --git a/src/main.go b/src/main.go
index 274f71b..91af40c 100644
--- a/src/main.go
+++ b/src/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"flag"
 	"fmt"
 	"log"
@@ -25,7 +26,7 @@ func FeatureActive(feature string) bool {
 }
 
 func listen(name string, listen string) net.Listener {
-	if listen == "" {
+	if listen == "-" {
 		return nil
 	}
 
@@ -79,6 +80,7 @@ func main() {
 	InitObservability()
 
 	configPath := flag.String("config", "config.toml", "path to configuration file")
+	printConfig := flag.Bool("print-config", false, "print final configuration as JSON")
 	getManifest := flag.String("get-manifest", "", "retrieve manifest for web root as ProtoJSON")
 	flag.Parse()
 
@@ -87,10 +89,16 @@ func main() {
 	}
 	UpdateConfigEnv() // environment takes priority
 
+	if *printConfig {
+		configJSON, _ := json.MarshalIndent(&config, "", "  ")
+		fmt.Println(string(configJSON))
+		return
+	}
+
 	switch config.LogFormat {
-	case "short":
+	case "message":
 		log.SetFlags(0)
-	default:
+	case "datetime+message":
 		log.SetFlags(log.Ldate | log.Ltime | log.LUTC)
 	}