The cloudprovider is being refactored out of kubernetes core. This is being
done by moving all the cloud-specific calls from kube-apiserver, kubelet and
kube-controller-manager into a separately maintained binary(by vendors) called
cloud-controller-manager. The Kubelet relies on the cloudprovider to detect information
about the node that it is running on. Some of the cloudproviders worked by
querying local information to obtain this information. In the new world of things,
local information cannot be relied on, since cloud-controller-manager will not
run on every node. Only one active instance of it will be run in the cluster.
Today, all calls to the cloudprovider are based on the nodename. Nodenames are
unqiue within the kubernetes cluster, but generally not unique within the cloud.
This model of addressing nodes by nodename will not work in the future because
local services cannot be queried to uniquely identify a node in the cloud. Therefore,
I propose that we perform all cloudprovider calls based on ProviderID. This ID is
a unique identifier for identifying a node on an external database (such as
the instanceID in aws cloud).
Many providers need to do some sort of node name -> IP or instanceID
lookup before they can use the list of hostnames passed to
EnsureLoadBalancer/UpdateLoadBalancer.
This change just passes the full Node object instead of simply the node
name, allowing providers to use the node's provider ID and cached
addresses without additional lookups. Using `node.Name` reproduces the
old behaviour.
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 is a better abstraction than passing in specific pieces of the
Service that each of the cloudproviders may or may not need. For
instance, many of the providers don't need a region, yet this is passed
in. Similarly many of the providers want a string IP for the load
balancer, but it passes in a converted net ip. Affinity is unused by
AWS. A provider change may also require adding a new parameter which has
an effect on all other cloud provider implementations.
Further, this will simplify adding provider specific load balancer
options, such as with labels or some other metadata. For example, we
could add labels for configuring the details of an AWS elastic load
balancer, such as idle timeout on connections, whether it is
internal or external, cross-zone load balancing, and so on.
Authors: @chbatey, @jsravn
This refactors #21431 to pull a lot of the code into cloudprovider so it
can be reused by AWS.
It also changes the name of the annotation to be non-GCE specific:
service.beta.kubernetes.io/load-balancer-source-ranges
Fix#21651
Previously the servicecontroller would do the delete, but by having the cloudprovider
take that task on, we can later remove it from the servicecontroller, and the
cloudprovider can do something more efficient.
wlan0