Refactor clustering setup code

caddytls/config.go

@@ -19,8 +19,6 @@ import (
 	"crypto/x509"
 	"fmt"
 	"io/ioutil"
-	"os"
-	"sync/atomic"
 	"time"
 
 	"github.com/go-acme/lego/challenge/tlsalpn01"
@@ -103,31 +101,14 @@ func NewConfig(inst *caddy.Instance) (*Config, error) {
 	certCache, ok := inst.Storage[CertCacheInstStorageKey].(*certmagic.Cache)
 	inst.StorageMu.RUnlock()
 	if !ok || certCache == nil {
-		// set up the clustering plugin, if there is one (and there should always
+		if err := makeClusteringPlugin(); err != nil {
-		// be one since this tls plugin requires it) -- this should be done exactly
+			return nil, err
-		// once, but we can't do it during init while plugins are still registering,
-		// so do it as soon as we run a setup)
-		if atomic.CompareAndSwapInt32(&clusterPluginSetup, 0, 1) {
-			clusterPluginName := os.Getenv("CADDY_CLUSTERING")
-			if clusterPluginName == "" {
-				clusterPluginName = "file" // name of default storage plugin
-			}
-			clusterFn, ok := clusterProviders[clusterPluginName]
-			if ok {
-				storage, err := clusterFn()
-				if err != nil {
-					return nil, fmt.Errorf("constructing cluster plugin %s: %v", clusterPluginName, err)
-				}
-				certmagic.Default.Storage = storage
-			} else {
-				return nil, fmt.Errorf("unrecognized cluster plugin (was it included in the Caddy build?): %s", clusterPluginName)
-			}
 		}
 		certCache = certmagic.NewCache(certmagic.CacheOptions{
 			GetConfigForCert: func(cert certmagic.Certificate) (certmagic.Config, error) {
-				inst.StorageMu.Lock()
+				inst.StorageMu.RLock()
 				cfgMap, ok := inst.Storage[configMapKey].(map[string]*Config)
-				inst.StorageMu.Unlock()
+				inst.StorageMu.RUnlock()
 				if ok {
 					for hostname, cfg := range cfgMap {
 						if cfg.Manager != nil && hostname == cert.Names[0] {
@@ -135,8 +116,6 @@ func NewConfig(inst *caddy.Instance) (*Config, error) {
 						}
 					}
 				}
-				// returning Default not strictly necessary, since Default is used as template
-				// anyway; but this makes it clear that that's what we fall back to
 				return certmagic.Default, nil
 			},
 		})

caddytls/setup.go

@@ -50,25 +50,8 @@ func init() {
 // are specified by the user in the config file. All the automatic HTTPS
 // stuff comes later outside of this function.
 func setupTLS(c *caddy.Controller) error {
-	// set up the clustering plugin, if there is one (and there should always
+	if err := makeClusteringPlugin(); err != nil {
-	// be one since this tls plugin requires it) -- this should be done exactly
+		return err
-	// once, but we can't do it during init while plugins are still registering,
-	// so do it as soon as we run a setup)
-	if atomic.CompareAndSwapInt32(&clusterPluginSetup, 0, 1) {
-		clusterPluginName := os.Getenv("CADDY_CLUSTERING")
-		if clusterPluginName == "" {
-			clusterPluginName = "file" // name of default storage plugin
-		}
-		clusterFn, ok := clusterProviders[clusterPluginName]
-		if ok {
-			storage, err := clusterFn()
-			if err != nil {
-				return fmt.Errorf("constructing cluster plugin %s: %v", clusterPluginName, err)
-			}
-			certmagic.Default.Storage = storage
-		} else {
-			return fmt.Errorf("unrecognized cluster plugin (was it included in the Caddy build?): %s", clusterPluginName)
-		}
 	}
 
 	configGetter, ok := configGetters[c.ServerType()]
@@ -464,6 +447,30 @@ func loadCertsInDir(cfg *Config, c *caddy.Controller, dir string) error {
 	})
 }
 
+func makeClusteringPlugin() error {
+	// set up the clustering plugin, if there is one (and there should always
+	// be one since this tls plugin requires it) -- this should be done exactly
+	// once, but we can't do it during init while plugins are still registering,
+	// so do it as soon as we run a setup)
+	if atomic.CompareAndSwapInt32(&clusterPluginSetup, 0, 1) {
+		clusterPluginName := os.Getenv("CADDY_CLUSTERING")
+		if clusterPluginName == "" {
+			clusterPluginName = "file" // name of default storage plugin
+		}
+		clusterFn, ok := clusterProviders[clusterPluginName]
+		if ok {
+			storage, err := clusterFn()
+			if err != nil {
+				return fmt.Errorf("constructing cluster plugin %s: %v", clusterPluginName, err)
+			}
+			certmagic.Default.Storage = storage
+		} else {
+			return fmt.Errorf("unrecognized cluster plugin (was it included in the Caddy build?): %s", clusterPluginName)
+		}
+	}
+	return nil
+}
+
 func constructDefaultClusterPlugin() (certmagic.Storage, error) {
 	return &certmagic.FileStorage{Path: caddy.AssetsPath()}, nil
 }