InitLogs overrides the klog default and turns contextual logging off. This
ensures that it is only enabled in Kubernetes commands that explicitly enable
it via a feature gate. A feature gate for it gets defined in
k8s.io/component-base/logs and is then used by Options.ValidateAndApply.
The effect of disabling contextual logging is very limited according to
benchmarks with kube-scheduler. The feature gets added anyway to satisfy the
PRR recommendation that features should be controllable.
The following commands have support for contextual logging:
- kube-apiserver
- kube-controller-manager
- kubelet
- kube-scheduler
- component-base/logs example
Supporting a feature gate check in ValidateAndApply and not in InitLogs is a
simplification: changing InitLogs to accept a FeatureGate would have implied
changing also component-base/cli.Run. This didn't seem worthwhile because
ValidateAndApply already covers the relevant commands.
All the controllers should use context for signalling termination of communication with API server. Once kcm cancels context all the cert controllers which are started via kcm should cancel the APIServer request in flight instead of hanging around.
This PR removes Serve function and uses all required places
ServeWithListenerStopped which takes place new Serve function.
This function returns ListenerStopped channel can be used to drain
requests before shutting down the server.
In various places log messages where emitted as part of validation or even
before it (for example, cli.PrintFlags). Those log messages did not use the
final logging configuration, for example text output instead of JSON or not the
final verbosity. The last point became more obvious after moving the setup of
verbosity into logs.Options.Apply because PrintFlags never printed anything
anymore.
In order to force applications to deal with logging as soon as possible, the
Options.Validate and Options.Apply methods are now private. Applications should
use the new Options.ValidateAndApply directly after parsing.
These three options are the ones from logs.AddFlags which are not deprecated.
Therefore it makes sense to make them available also via the configuration file
support in the one command which currently supports that (kubelet).
Long-term, all commands should use LoggingConfiguration, either with a
configuration file (as in kubelet) or via flags (kube-scheduler,
kube-apiserver, kube-controller-manager).
Short-term, both approaches have to be supported. As the majority of the
commands only use logs.AddFlags, that function by default continues to register
the flags and only leaves that to Options.AddFlags when explicitly requested.
A drive-by bug fix is done for log flushing: the periodic flushing called
klog.Flush and therefore missed explicit flushing of the newer logr
backend. This bug was never present in any release Kubernetes and therefore the
fix is not submitted in a separate PR.
This feature has graduated to GA in v1.11 and will always be
enabled. So no longe need to check if enabled.
Signed-off-by: Konstantin Misyutin <konstantin.misyutin@huawei.com>
The feature gate gets locked to "true", with the goal to remove it in two
releases.
All code now can assume that the feature is enabled. Tests for "feature
disabled" are no longer needed and get removed.
Some code wasn't using the new helper functions yet. That gets changed while
touching those lines.
All Kubernetes commands should show flags with hyphens in their help text even
when the flag originally was defined with underscore. Converting a command to
this style is not breaking its command line API because the old-style parameter
with underscore is accepted as alias.
The easiest solution to achieve this is to set normalization shortly before
running the command in the new central cli.Run or the few places where that
function isn't used yet.
There may be some texts which depends on normalization at flag definition time,
like the --logging-format usage warning. Those get generated assuming that
hyphens will be used.
It wasn't documented that InitLogs already uses the log flush frequency, so
some commands have called it before parsing (for example, kubectl in the
original code for logs.go). The flag never had an effect in such commands.
Fixing this turned into a major refactoring of how commands set up flags and
run their Cobra command:
- component-base/logs: implicitely registering flags during package init is an
anti-pattern that makes it impossible to use the package in commands which
want full control over their command line. Logging flags must be added
explicitly now, something that the new cli.Run does automatically.
- component-base/logs: AddFlags would have crashed in kubectl-convert if it
had been called because it relied on the global pflag.CommandLine. This
has been fixed and kubectl-convert now has the same --log-flush-frequency
flag as other commands.
- component-base/logs/testinit: an exception are tests where flag.CommandLine has
to be used. This new package can be imported to add flags to that
once per test program.
- Normalization of the klog command line flags was inconsistent. Some commands
unintentionally didn't normalize to the recommended format with hyphens. This
gets fixed for sample programs, but not for production programs because
it would be a breaking change.
This refactoring has the following user-visible effects:
- The validation error for `go run ./cmd/kube-apiserver --logging-format=json
--add-dir-header` now references `add-dir-header` instead of `add_dir_header`.
- `staging/src/k8s.io/cloud-provider/sample` uses flags with hyphen instead of
underscore.
- `--log-flush-frequency` is not listed anymore in the --logging-format flag's
`non-default formats don't honor these flags` usage text because it will also
work for non-default formats once it is needed.
- `cmd/kubelet`: the description of `--logging-format` uses hyphens instead of
underscores for the flags, which now matches what the command is using.
- `staging/src/k8s.io/component-base/logs/example/cmd`: added logging flags.
- `apiextensions-apiserver` no longer prints a useless stack trace for `main`
when command line parsing raises an error.
Due to a cut-and-paste error in the original implementation in Kubernetes 1.19,
support for generic ephemeral inline volumes in the PVC protection controller
was incorrectly tied to the "storage object in use" feature gate.
This change updates the CSR API to add a new, optional field called
expirationSeconds. This field is a request to the signer for the
maximum duration the client wishes the cert to have. The signer is
free to ignore this request based on its own internal policy. The
signers built-in to KCM will honor this field if it is not set to a
value greater than --cluster-signing-duration. The minimum allowed
value for this field is 600 seconds (ten minutes).
This change will help enforce safer durations for certificates in
the Kube ecosystem and will help related projects such as
cert-manager with their migration to the Kube CSR API.
Future enhancements may update the Kubelet to take advantage of this
field when it is configured in a way that can tolerate shorter
certificate lifespans with regular rotation.
Signed-off-by: Monis Khan <mok@vmware.com>
FeatureGate acts as a secondary switch to disable cloud-controller loops
in KCM, Kubelet and KAPI.
Provide comprehensive logging information to users, so they will be
guided in adoption of out-of-tree cloud provider implementation.
Now the following flags have no effect and would be removed in v1.24:
* `--port`
* `--address`
The insecure port flags `--port` may only be set to 0 now.
Signed-off-by: Jian Zeng <zengjian.zj@bytedance.com>
it turns out that setting a timeout on HTTP client affect watch requests made by the delegated authentication component.
with a 10 second timeout watch requests are being re-established exactly after 10 seconds even though the default request timeout for them is ~5 minutes.
this is because if multiple timeouts were set, the stdlib picks the smaller timeout to be applied, leaving other useless.
for more details see a937729c2c/src/net/http/client.go (L364)
instead of setting a timeout on the HTTP client we should use context for cancellation.
