func (r *Router) serve(serfClient *client.RPCClient) error {
var (
eventCh chan client.EventRecord
)
// register for member events, user events and queries
eventCh = make(chan client.EventRecord)
if _, err := serfClient.Stream("member-join,member-leave,member-failed,user,query", eventCh); err != nil {
return fmt.Errorf("failed to initialize event stream. Error: %s", err)
}
for {
select {
case e, ok := <-eventCh:
if !ok {
return fmt.Errorf("event channel was unexpectedly closed")
}
log.Infof("Event received: %+v", e)
if _, ok := e.(client.QueryEventRecord); ok {
r.handleQuery(serfClient, e.(client.QueryEventRecord))
} else {
r.handleEvent(e)
}
}
}
}
func (r *Router) handleQuery(serfClient *client.RPCClient, query client.QueryEventRecord) {
r.Lock()
defer r.Unlock()
var (
response []byte
handlerFunc ResponderFunc
ok bool
err error
)
if f := r.findHandlerFunc(query.Name); f == nil {
log.Infof("no handler for query: %q", query.Name)
return
} else if handlerFunc, ok = f.(ResponderFunc); !ok {
log.Infof("no handler for query: %q", query.Name)
return
}
if response, err = handlerFunc(query.Name, query); err != nil {
log.Infof("query handler failed. Error: %s", err)
// failure returned by handlers are not considered fatal
// TODO: handle panics inside event handlers as well
return
}
if err := serfClient.Respond(query.ID, response); err != nil {
log.Errorf("responding to query failed. Response body: %v, Error: %s", response, err)
}
}