kubectl command construction is slowly getting more functionality which
sometimes requires to log certain actions. Currently we parse the
verbosity only when actually running the command, so all of construction
code is not able to use -v=5. This commit adds the manual parsing and
loglevel setting berore we even start creating the kubectl command.
Signed-off-by: Maciej Szulik <soltysh@gmail.com>
cli.Run was an attempt to elliminate error handling in Kubernetes
commands. However, it had to rely on heuristics that are not necessarily right
for all commands.
kubectl is one example which has its own error printing code that should be
used in all cases after a command failure. It now gets used also for
`--warnings-as-errors`. Previously, that caused the following message to be
logged at the end:
E0110 16:56:01.987555 202060 run.go:120] "command failed" err="1 warning received"
Now it ends with:
error: 1 warning received
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.
Maciej Szulik
Patrick Ohly
Maciej Szulik
Kubernetes Prow Robot
Odin Ugedal
Mike Dame
Marek Counts
Mikhail Mazurskiy
xuzhonghu
Mike Danese
David Eads
huzhifeng
Lucas Käldström
David McMahon
Brendan Burns
Mike Danese
Eric Paris
Andy Goldstein
Daniel Smith
Clayton Coleman
Sam Ghods