func createDashboardNode(conn zkhelper.Conn) error {
// make sure root dir is exists
rootDir := fmt.Sprintf("/zk/reborn/db_%s", globalEnv.ProductName())
zkhelper.CreateRecursive(conn, rootDir, "", 0, zkhelper.DefaultDirACLs())
coordPath := fmt.Sprintf("%s/dashboard", rootDir)
// make sure we're the only one dashboard
timeoutCh := time.After(60 * time.Second)
for {
if exists, _, ch, _ := conn.ExistsW(coordPath); exists {
data, _, _ := conn.Get(coordPath)
if checkDashboardAlive(data) {
return errors.Errorf("dashboard already exists: %s", string(data))
} else {
log.Warningf("dashboard %s exists in zk, wait it removed", data)
select {
case <-ch:
case <-timeoutCh:
return errors.Errorf("wait existed dashboard %s removed timeout", string(data))
}
}
} else {
break
}
}
content := fmt.Sprintf(`{"addr": "%v", "pid": %v}`, globalEnv.DashboardAddr(), os.Getpid())
pathCreated, err := conn.Create(coordPath, []byte(content),
zk.FlagEphemeral, zkhelper.DefaultFileACLs())
log.Infof("dashboard node %s created, data %s, err %v", pathCreated, string(content), err)
return errors.Trace(err)
}