It is not uncommon for users to Create a Service and not specify things
like ClusterIP and NodePort, which we then allocate for them. They same
that YAML somewhere and later use it again in an Update, but then it
fails.
That's because we detected them trying to set a ClusterIP from a value
to "", which is not allowed. If it was just NodePort, they would
actually succeed and reallocate a new port.
After this change, we try to "patch" updates where the user did not
specify those values from the old object.
During operations such as "upgrade", kubeadm fetches the
ClusterConfiguration object from the kubeadm ConfigMap.
However, due to requiring node specifics it wraps it in an
InitConfiguration object. The function responsible for that is:
app/util/config#FetchInitConfigurationFromCluster().
A problem with this function (and sub-calls) is that it ignores
the static defaults applied from versioned types
(e.g. v1beta3/defaults.go) and only applies dynamic defaults for:
- API endpoints
- node registration
- etc...
The introduction of Init|JoinConfiguration.ImagePullPolicy now
has static defaulting of the NodeRegistration object with a default
policy of "PullIfNotPresent". Respect this defaulting by constructing
a defaulted internal InitConfiguration from
FetchInitConfigurationFromCluster() and only then apply the dynamic
defaults over it.
This fixes a bug where "kubeadm upgrade ..." fails when pulling images
due to an empty ("") ImagePullPolicy. We could assume that empty
string means default policy on runtime in:
cmd/kubeadm/app/preflight/checks.go#ImagePullCheck()
but that might actually not be the user intent during "init" and "join",
due to e.g. a typo. Similarly, we don't allow empty tokens
on runtime and error out.
* set `endpoints.kubernetes.io/over-capacity` to "truncated" when
number of addresses has been truncated to a 1000
* ready addresses are prioritized over non-ready addresses
* addresses are proportionally truncated across subsets
As of now, we allow PDBs to be applied to pods via
selectors, so there can be unmanaged pods(pods that
don't have backing controllers) but still have PDBs associated.
Such pods are to be logged instead of immediately throwing
a sync error. This ensures disruption controller is
not frequently updating the status subresource and thus
preventing excessive and expensive writes to etcd.
oomwatcher.NewWatcher returns "open /dev/kmsg: operation not permitted" error,
when running with sysctl value `kernel.dmesg_restrict=1`.
The error is negligible for KubeletInUserNamespace.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
