Pinning the kube-controller-manager and kube-scheduler kubeconfig files
to point to the control-plane-endpoint can be problematic during
immutable upgrades if one of these components ends up contacting an N-1
kube-apiserver:
https://kubernetes.io/docs/setup/release/version-skew-policy/#kube-controller-manager-kube-scheduler-and-cloud-controller-manager
For example, the components can send a request for a non-existing API
version.
Instead of using the CPE for these components, use the LocalAPIEndpoint.
This guarantees that the components would talk to the local
kube-apiserver, which should be the same version, unless the user
explicitly patched manifests.
For historical reasons InitConfiguration is used almost everywhere in kubeadm
as a carrier of various configuration components such as ClusterConfiguration,
local API server endpoint, node registration settings, etc.
Since v1alpha2, InitConfiguration is meant to be used solely as a way to supply
the kubeadm init configuration from a config file. Its usage outside of this
context is caused by technical dept, it's clunky and requires hacks to fetch a
working InitConfiguration from the cluster (as it's not stored in the config
map in its entirety).
This change is a small step towards removing all unnecessary usages of
InitConfiguration. It reduces its usage by replacing it in some places with
some of the following:
- ClusterConfiguration only.
- APIEndpoint (as local API server endpoint).
- NodeRegistrationOptions only.
- Some combinations of the above types, or if single fields from them are used,
only those field.
Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com>
Added hostport and host/port parts to the error messages
produced by ParseHostPort API.
This should help users to better identify parsing issues.
Fixes: kubernetes/kubeadm#1159
When `API.ControlPlaneEndpoint` is used, the `BindPort` of the
apiserver is currently assumed, which means a load balancer cannot
listen on a different port than the apiserver. This extends the
`ControlPlaneEndpoint` to take an optional port which may differ
from the apiserver's `BindPort`.
Previously, kubeadm would use <ip>:<port> to construct a master
endpoint. This works fine for IPv4 addresses, but not for IPv6.
IPv6 requires the ip to be encased in brackets when being joined
to a port with a colon.
This patch updates kubeadm to support wrapping a v6 address with
[] to form the master endpoint url. Since this functionality is
needed in multiple areas, a dedicated util function was created.
Fixes: https://github.com/kubernetes/kubernetes/issues/48227
