caddytls: Allow disabling storage cleaning, avoids writing two files (#6593)

caddyconfig/httpcaddyfile/options.go

@@ -39,7 +39,8 @@ func init() {
 	RegisterGlobalOption("fallback_sni", parseOptSingleString)
 	RegisterGlobalOption("order", parseOptOrder)
 	RegisterGlobalOption("storage", parseOptStorage)
-	RegisterGlobalOption("storage_clean_interval", parseOptDuration)
+	RegisterGlobalOption("storage_check", parseStorageCheck)
+	RegisterGlobalOption("storage_clean_interval", parseStorageCleanInterval)
 	RegisterGlobalOption("renew_interval", parseOptDuration)
 	RegisterGlobalOption("ocsp_interval", parseOptDuration)
 	RegisterGlobalOption("acme_ca", parseOptSingleString)
@@ -189,6 +190,40 @@ func parseOptStorage(d *caddyfile.Dispenser, _ any) (any, error) {
 	return storage, nil
 }
 
+func parseStorageCheck(d *caddyfile.Dispenser, _ any) (any, error) {
+	d.Next() // consume option name
+	if !d.Next() {
+		return "", d.ArgErr()
+	}
+	val := d.Val()
+	if d.Next() {
+		return "", d.ArgErr()
+	}
+	if val != "off" {
+		return "", d.Errf("storage_check must be 'off'")
+	}
+	return val, nil
+}
+
+func parseStorageCleanInterval(d *caddyfile.Dispenser, _ any) (any, error) {
+	d.Next() // consume option name
+	if !d.Next() {
+		return "", d.ArgErr()
+	}
+	val := d.Val()
+	if d.Next() {
+		return "", d.ArgErr()
+	}
+	if val == "off" {
+		return false, nil
+	}
+	dur, err := caddy.ParseDuration(d.Val())
+	if err != nil {
+		return nil, d.Errf("failed to parse storage_clean_interval, must be a duration or 'off' %w", err)
+	}
+	return caddy.Duration(dur), nil
+}
+
 func parseOptDuration(d *caddyfile.Dispenser, _ any) (any, error) {
 	if !d.Next() { // consume option name
 		return nil, d.ArgErr()

caddyconfig/httpcaddyfile/tlsapp.go

@@ -349,6 +349,16 @@ func (st ServerType) buildTLSApp(
 		tlsApp.Automation.OnDemand = onDemand
 	}
 
+	// if the storage clean interval is a boolean, then it's "off" to disable cleaning
+	if sc, ok := options["storage_check"].(string); ok && sc == "off" {
+		tlsApp.DisableStorageCheck = true
+	}
+
+	// if the storage clean interval is a boolean, then it's "off" to disable cleaning
+	if sci, ok := options["storage_clean_interval"].(bool); ok && !sci {
+		tlsApp.DisableStorageClean = true
+	}
+
 	// set the storage clean interval if configured
 	if storageCleanInterval, ok := options["storage_clean_interval"].(caddy.Duration); ok {
 		if tlsApp.Automation == nil {

caddytest/integration/caddyfile_adapt/global_options.caddyfiletest

@@ -9,6 +9,8 @@
 	storage file_system {
 		root /data
 	}
+	storage_check off
+	storage_clean_interval off
 	acme_ca https://example.com
 	acme_ca_root /path/to/ca.crt
 	ocsp_stapling off
@@ -73,7 +75,9 @@
 					}
 				}
 			},
-			"disable_ocsp_stapling": true
+			"disable_ocsp_stapling": true,
+			"disable_storage_check": true,
+			"disable_storage_clean": true
 		}
 	}
 }

modules/caddytls/tls.go

@@ -92,6 +92,17 @@ type TLS struct {
 	// EXPERIMENTAL. Subject to change.
 	DisableStorageCheck bool `json:"disable_storage_check,omitempty"`
 
+	// Disables the automatic cleanup of the storage backend.
+	// This is useful when TLS is not being used to store certificates
+	// and the user wants run their server in a read-only mode.
+	//
+	// Storage cleaning creates two files: instance.uuid and last_clean.json.
+	// The instance.uuid file is used to identify the instance of Caddy
+	// in a cluster. The last_clean.json file is used to store the last
+	// time the storage was cleaned.
+	// EXPERIMENTAL. Subject to change.
+	DisableStorageClean bool `json:"disable_storage_clean,omitempty"`
+
 	certificateLoaders []CertificateLoader
 	automateNames      []string
 	ctx                caddy.Context
@@ -328,7 +339,11 @@ func (t *TLS) Start() error {
 		return fmt.Errorf("automate: managing %v: %v", t.automateNames, err)
 	}
 
+	if !t.DisableStorageClean {
+		// start the storage cleaner goroutine and ticker,
+		// which cleans out expired certificates and more
 		t.keepStorageClean()
+	}
 
 	return nil
 }