The isCoreDNSVersionSupported() check assumes that
there is a running kubelet, that manages the CoreDNS containers.
If the containers are being created it is not possible to fetch
their image digest. To workaround that, a poll can be used in
isCoreDNSVersionSupported() and wait for the CoreDNS Pods
are expected to be running. Depending on timing and CNI
yet to be installed this can cause problems related to
addon idempotency of "kubeadm init", because if the CoreDNS
Pods are waiting for another step they will never get running.
Remove the function isCoreDNSVersionSupported() and assume that
the version is always supported. Rely on the Corefile migration
library to error out if it must.
A bug was discovered in the `enforceRequirements` func for `upgrade plan`.
If a command line argument that specifies the target Kubernetes version is
supplied, the returned `ClusterConfiguration` by `enforceRequirements` will
have its `KubernetesVersion` field set to the new version.
If no version was specified, the returned `KubernetesVersion` points to the
currently installed one.
This remained undetected for a couple of reasons
- It's only `upgrade plan` that allows for the version command line argument to
be optional (in `upgrade plan` it's mandatory)
- Prior to 1.19, the implementation of `upgrade plan` did not make use of the
`KubernetesVersion` returned by `enforceRequirements`.
`upgrade plan` supports this optional command line argument to enable
air-gapped setups (as not specifying a version on the command line will end up
looking for the latest version over the Interned).
Hence, the only option is to make `enforceRequirements` consistent in the
`upgrade plan` case and always return the currently installed version in the
`KubernetesVersion` field.
Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com>
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.
A check that verifies that kubeadm does not "upgrade" to an older release was
overly optimized by skipping upgrade if the new version is the same as the old
one. This somewhat makes sense, but that way changes in any of the etcd fields
in the ClusterConfiguration won't be applied if the etcd version is not
changed.
Hence, this simple change ensures that the upgrade is done even when no version
change takes place.
Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com>
* Creates private keys and CSR files for all the control-plane certificates
* Helps with External CA mode of kubeadm
Signed-off-by: Richard Wall <richard.wall@jetstack.io>
Back in the v1alpha2 days the fuzzer test needed to be disabled. To ensure that
there were no config breaks and everything worked correctly extensive replacement
tests were put in place that functioned as unit tests for the kubeadm config utils
as well.
The fuzzer test has been reenabled for a long time now and there's no need for
these replacements. Hence, over time most of these were disabled, deleted and
refactored. The last remnants are part of the LoadJoinConfigurationFromFile test.
The test data for those old tests remains largely unused today, but it still receives
updates as it contains kubelet's and kube-proxy's component configs. Updates to these
configs are usually done because the maintainers of those need to add a new field.
Hence, to cleanup old code and reduce maintenance burden, the last test that depends
on this test data is finally refactored and cleaned up to represent a simple unit test
of `LoadJoinConfigurationFromFile`.
Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com>
Over the course of recent development of the `componentconfigs` package,
it became evident that most of the tests in this package cannot be implemented without
using a component config. As all of the currently supported component configs are
external to the kubeadm project (kubelet and kube-proxy), practically all of the tests
in this package are now dependent on external code.
This is not desirable, because other component's configs may change frequently and
without much of a notice. In particular many configs add new fields without bumping their
versions. In addition to that, some components may be deprecated in the future and many
tests may use their configs as a place holder of a component config just to test some
common functionality.
To top that, there are many tests that test the same common functionality several times
(for each different component config).
Thus a kubeadm managed replacement and a fake test environment are introduced.
The new test environment uses kubeadm's very own `ClusterConfiguration`.
ClusterConfiguration is normally not managed by the `componentconfigs` package.
It's only used, because of the following:
- It's a versioned API that is under the control of kubeadm maintainers. This enables us to test
the componentconfigs package more thoroughly without having to have full and always up to date
knowledge about the config of another component.
- Other components often introduce new fields in their configs without bumping up the config version.
This, often times, requires that the PR that introduces such new fields to touch kubeadm test code.
Doing so, requires more work on the part of developers and reviewers. When kubeadm moves out of k/k
this would allow for more sporadic breaks in kubeadm tests as PRs that merge in k/k and introduce
new fields won't be able to fix the tests in kubeadm.
- If we implement tests for all common functionality using the config of another component and it gets
deprecated and/or we stop supporting it in production, we'll have to focus on a massive test refactoring
or just continue importing this config just for test use.
Thus, to reduce maintenance costs without sacrificing test coverage, we introduce this mini-framework
and set of tests here which replace the normal component configs with a single one (`ClusterConfiguration`)
and test the component config independent logic of this package.
As a result of this, many of the older test cases are refactored and greatly simplified to reflect
on the new change as well. The old tests that are strictly tied to specific component configs
(like the defaulting tests) are left unchanged.
Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com>
