// register is used for registration of node with particular dispatcher.
func (d *Dispatcher) register(ctx context.Context, nodeID string, description *api.NodeDescription) (string, error) {
// prevent register until we're ready to accept it
if err := d.isRunningLocked(); err != nil {
return "", err
}
if err := d.nodes.CheckRateLimit(nodeID); err != nil {
return "", err
}
// create or update node in store
// TODO(stevvooe): Validate node specification.
var node *api.Node
err := d.store.Update(func(tx store.Tx) error {
node = store.GetNode(tx, nodeID)
if node == nil {
return ErrNodeNotFound
}
node.Description = description
node.Status = api.NodeStatus{
State: api.NodeStatus_READY,
}
return store.UpdateNode(tx, node)
})
if err != nil {
return "", err
}
expireFunc := func() {
nodeStatus := api.NodeStatus{State: api.NodeStatus_DOWN, Message: "heartbeat failure"}
log.G(ctx).Debugf("heartbeat expiration")
if err := d.nodeRemove(nodeID, nodeStatus); err != nil {
log.G(ctx).WithError(err).Errorf("failed deregistering node after heartbeat expiration")
}
}
rn := d.nodes.Add(node, expireFunc)
// NOTE(stevvooe): We need be a little careful with re-registration. The
// current implementation just matches the node id and then gives away the
// sessionID. If we ever want to use sessionID as a secret, which we may
// want to, this is giving away the keys to the kitchen.
//
// The right behavior is going to be informed by identity. Basically, each
// time a node registers, we invalidate the session and issue a new
// session, once identity is proven. This will cause misbehaved agents to
// be kicked when multiple connections are made.
return rn.SessionID, nil
}
