Merge pull request #841 from abronan/consul_ttl_check

Additional check for ttl < 10s and Consul

discovery/kv/kv.go

@@ -62,6 +62,7 @@ func (s *Discovery) Initialize(uris string, heartbeat time.Duration, ttl time.Du
 			EphemeralTTL: s.ttl,
 		},
 	)
+
 	return err
 }
 

pkg/store/consul.go

@@ -16,6 +16,10 @@ const (
 	// watched key has changed.  This affects the minimum time it takes to
 	// cancel a watch.
 	DefaultWatchWaitTime = 15 * time.Second
+
+	// MinimumTimeToLive is the minimum TTL value allowed by Consul for
+	// Ephemeral entries
+	MinimumTimeToLive = 10 * time.Second
 )
 
 // Consul embeds the client and watches
@@ -52,7 +56,9 @@ func InitializeConsul(endpoints []string, options *Config) (Store, error) {
 			s.setTimeout(options.ConnectionTimeout)
 		}
 		if options.EphemeralTTL != 0 {
-			s.setEphemeralTTL(options.EphemeralTTL)
+			if err := s.setEphemeralTTL(options.EphemeralTTL); err != nil {
+				return nil, err
+			}
 		}
 	}
 
@@ -81,8 +87,12 @@ func (s *Consul) setTimeout(time time.Duration) {
 }
 
 // SetEphemeralTTL sets the ttl for ephemeral nodes
-func (s *Consul) setEphemeralTTL(time time.Duration) {
-	s.ephemeralTTL = time
+func (s *Consul) setEphemeralTTL(ttl time.Duration) error {
+	if ttl < MinimumTimeToLive {
+		return ErrInvalidTTL
+	}
+	s.ephemeralTTL = ttl
+	return nil
 }
 
 // CreateEphemeralSession creates the a global session

pkg/store/store.go

@@ -23,6 +23,8 @@ const (
 )
 
 var (
+	// ErrInvalidTTL is a specific error to consul
+	ErrInvalidTTL = errors.New("Invalid TTL, please change the value to the miminum allowed ttl for the chosen store")
 	// ErrNotSupported is exported
 	ErrNotSupported = errors.New("Backend storage not supported yet, please choose another one")
 	// ErrNotImplemented is exported