View source for EKS Node Group Nodes Not Able to Join the Cluster

=Internal=
* [[Amazon_EKS_Operations#Node_Group_Nodes_Not_Able_to_Join_the_Cluster|Amazon EKS Operations]]

=Overview=

Creation of a new node group takes a long time, and eventually the state transitions to "Create failed". The corresponding autoscaling group is correctly created and the nodes are healthy.  Yet, they cannot join the cluster. 

=Root Cause=

The problem is caused by the fact that [[Amazon_EKS_Concepts#Cluster_Security_Group|cluster security group]] loses all its inbound rules.

=Fix=

Locate the EKS cluster's [[Amazon_EKS_Concepts#Cluster_Security_Group|cluster security group]].

Add itself as an inbound rule: Type "All traffic", Source "Custom", data: its own ID.