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.
Since we never use the cobras "SilenceErrors" or "SilenceUsage",
a command executed with "cmd.Execute()" will never return an error
without printing it.
The current behavior results in all error messages being printed twice:
Example:
$ kubectl abc
Error: unknown command "abc" for "kubectl"
Run 'kubectl --help' for usage.
unknown command "abc" for "kubectl"
This applies to all cli commands using Cobra. To verify, follow the code
path of the Execute function:
https://github.com/spf13/cobra/blob/c439c4fa0937/command.go#L793
Signed-off-by: Odin Ugedal <odin@ugedal.com>
Moved all flag code from `staging/src/k8s.io/apiserver/pkg/util/[flag|globalflag]` to `component-base/cli/[flag|globalflag]` except for the term function because of unwanted dependencies.
- /healthz will be served on 0.0.0.0:10256 by default.
- /metrics and /proxyMode will be served on port 10249
as before.
- Healthz handler will verify timestamp in iptables mode.
I had the kublet die on startup and the only error was "0x401da0" Which
I assume is an address of the err.Error function. The other way to fix
this, I think, would be to use err.Error(), however that could cause
fmt.Fprintf() problems, debuging on the error message people used.
Now I get a nice clean error I can understand:
"cAdvisor.New() err = mountpoint for cpu not found"
It currently is impossible to use two healthz handlers on different
ports in the same process. This removes the global variables in favor
of requiring the consumer to specify all health checks up front.
RegisterHandlers was called after the listening for events had already begun.
So, there was a race where sometimes the first update would, with the
initial state, would notify an empty list of listeners.
This showed up in services.sh e2e test as empty service and endpoint maps
after the test step which restarts the kube-proxy.
Perhaps due to timing, this doesn't show up with etcd source, but does
show up with apiserver as a source. A separate PR makes APIserver
the source as a default, and depends on this.
This took me several days to debug.
apiserver becomes kube-apiserver
controller-manager -> kube-controller-manager
scheduler and proxy similarly.
Only thing I promise is that right now hack/build-go.sh and
build/release.sh exit with 0. That's it. Who knows if any of this
actually works....
