We recognize an additional cluster tag:
kubernetes.io/cluster/<clusterid>
This now allows us to share resources, in particular subnets.
In addition, the value is used to track ownership/lifecycle. When we
create objects, we record the value as "owned".
We also refactor out tags into its own file & class, as we are touching
most of these functions anyway.
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.
If a route already exists but is invalid (e.g. from a crash), we
automatically delete it before trying to create a route that would
otherwise conflict.
Henrik Schmidt