Apply a small fix to ensure the kubeconfig files
that kubeadm manages have a CA when printed in the table
of the "check expiration" command. "CAName" is the field used for that.
In practice kubeconfig files can contain multiple credentials
from different CAs, but this is not supported by kubeadm and there
is a single cluster CA that signs the single client cert/key
in kubeadm managed kubeconfigs.
In case stacked etcd is used, the code that does expiration checks
does not validate if the etcd CA is "external" (missing key)
and if the etcd CA signed certificates are valid.
Add a new function UsingExternalEtcdCA() similar to existing functions
for the cluster CA and front-proxy CA, that performs the checks for
missing etcd CA key and certificate validity.
This function only runs for stacked etcd, since if etcd is external
kubeadm does not track any certs signed by that etcd CA.
This fixes a bug where the etcd CA will be reported as local even
if the etcd/ca.key is missing during "certs check-expiration".
The flag "--use-api" for "alpha certs renew" was deprecated in 1.18.
Remove the flag and related logic that executes certificate renewal
using "api/certificates/v1beta1". kubeadm continues to be able
to create CSR files and renew using the local CA on disk.
The selected key type is defined by kubeadm's --feature-gates option:
if it contains PublicKeysECDSA=true then ECDSA keys will be generated
and used.
By default RSA keys are used still.
Signed-off-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
While kubeadm does not support CA rotation,
the users might still attempt to perform this manually.
For kubeconfig files, updating to a new CA is not reflected
and users need to embed new CA PEM manually.
On kubeconfig cert renewal, always keep the embedded CA
in sync with the one on disk.
Includes a couple of typo fixes.
