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.
The `-mod=mod` option is only supported from go1.14. Since `release-1.18`
and `release-1.17` branches use go1.13.15, this commit adds smoke tests
per branch to only add the `-mod=mod` option to branches after
`release-1.18`.
The duplicate smoke test config can be removed once v1.21 is released
and v1.18 is out of support.
With the move to go1.16, we are hitting a go bug for how
`go build`/`go test` work with modules - golang/go#44129.
This commit adds the `-mod=mod` flag for `go build` and `go test`
commands in the smoke test rules (workaround mentioned in the issue).
The alternative to this would be to special-case code-generator. Since
it legit wants codegen, it seems wrong to make it be _examples (which tools
should ignore).
Make examples an "internal module" so the main go.mod for
k8s.io/code-generator does not get too polluted.
