We had another bug where we confused the hostname with the NodeName.
To avoid this happening again, and to make the code more
self-documenting, we use types.NodeName (a typedef alias for string)
whenever we are referring to the Node.Name.
A tedious but mechanical commit therefore, to change all uses of the
node name to use types.NodeName
Also clean up some of the (many) places where the NodeName is referred
to as a hostname (not true on AWS), or an instanceID (not true on GCE),
etc.
This PR tries to fix issue #29324. This cause of this issue is a race
condition happens when marking volumes as attached for node status. This
PR tries to clean up the logic of when and where to mark volumes as
attached/detached. Basically the workflow as follows,
1. When volume is attached sucessfully, the volume and node info is
added into nodesToUpdateStatusFor to mark the volume as attached to the
node.
2. When detach request comes in, it will check whether it is safe to
detach now. If the check passes, remove the volume from volumesToReportAsAttached
to indicate the volume is no longer considered as attached now.
Afterwards, reconciler tries to update node status and trigger detach
operation. If any of these operation fails, the volume is added back to
the volumesToReportAsAttached list showing that it is still attached.
These steps should make sure that kubelet get the right (might be
outdated) information about which volume is attached or not. It also
garantees that if detach operation is pending, kubelet should not
trigger any mount operations.
Allow mount volume operations to run in parallel for non-attachable
volume plugins.
Allow unmount volume operations to run in parallel for all volume
plugins.
