cookie: implement garbage collector

contrib/sample-cfg.yml

@@ -32,6 +32,7 @@ cookie:
   #     ## generate with `openssl pkey -in ./contrib/bar_ed25519_priv.pem -pubout -out ./contrib/bar_ed25519_pub.pem`
   #     public-key-file: ./contrib/bar_ed25519_pub.pem
   backend:
+    # gc-interval: 10s
     in-memory: {}
 
 auth:

cookie/backend_in-memory.go

@@ -121,14 +121,16 @@ func (b *InMemoryBackend) ListRevoked() (list StoredSessionList, err error) {
 	return
 }
 
-func (b *InMemoryBackend) CollectGarbage() error {
+func (b *InMemoryBackend) CollectGarbage() (uint, error) {
 	b.mutex.RLock()
 	defer b.mutex.RUnlock()
 
+	cnt := uint(0)
 	for _, sessions := range b.sessions {
 		for id, session := range sessions {
 			if session.IsExpired() {
 				delete(sessions, id)
+				cnt = cnt + 1
 			}
 		}
 	}
@@ -138,5 +140,5 @@ func (b *InMemoryBackend) CollectGarbage() error {
 		}
 	}
 
-	return nil
+	return cnt, nil
 }

cookie/store.go

@@ -51,7 +51,8 @@ type SignerVerifierConfig struct {
 }
 
 type StoreBackendConfig struct {
-	InMemory *InMemoryBackendConfig `yaml:"in-memory"`
+	GCInterval time.Duration          `yaml:"gc-interval"`
+	InMemory   *InMemoryBackendConfig `yaml:"in-memory"`
 }
 
 type Config struct {
@@ -96,7 +97,7 @@ type StoreBackend interface {
 	Revoke(username string, id ulid.ULID) error
 	IsRevoked(id ulid.ULID) (bool, error)
 	ListRevoked() (StoredSessionList, error)
-	CollectGarbage() error
+	CollectGarbage() (uint, error)
 }
 
 type Options struct {
@@ -180,13 +181,42 @@ func (st *Store) initKeys(conf *Config) (err error) {
 	return
 }
 
+func (st *Store) runGC(interval time.Duration) {
+	t := time.NewTicker(interval)
+	st.dbgLog.Printf("cookie-store: running GC every %v", interval)
+	for {
+		if _, ok := <-t.C; !ok {
+			return
+		}
+		cnt, err := st.backend.CollectGarbage()
+		if err != nil {
+			st.infoLog.Printf("cookie-store: failed to collect garbage: %v", err)
+		}
+		if cnt > 0 {
+			st.dbgLog.Printf("cookie-store: GC removed %d expired sessions", cnt)
+		}
+	}
+}
+
 func (st *Store) initBackend(conf *Config) (err error) {
+	if conf.Backend.GCInterval <= time.Second {
+		st.infoLog.Printf("cookie-store: overriding invalid/unset GC interval to 5 minutes")
+		conf.Backend.GCInterval = 5 * time.Minute
+	}
+
 	if conf.Backend.InMemory != nil {
 		st.backend, err = NewInMemoryBackend(conf.Backend.InMemory)
+		if err != nil {
+			return err
+		}
+	}
+	// TODO: add other backend types
+	if st.backend == nil {
+		err = fmt.Errorf("no valid backend configuration found")
 		return
 	}
-	// TODO: add garbage collector!!
-	err = fmt.Errorf("no valid backend configuration found")
+
+	go st.runGC(conf.Backend.GCInterval)
 	return
 }