Output usage only when flag parsing fails

[ffjlabo]

What would you like to be added:

I propose that clis output usage only when flag parsing fails, not when internal errors occur.

Why is this needed:

When I tried to do quickstart with pipectl, an error occurs.

I tried to do quickstart with pipectl and encounter the error log below
At first glance, it seems that only the stack trace is displayed, but in fact the specific error message is displayed at the bottom.
In my opinion, it is difficult to find the message quickly.

% pipectl quickstart --version v0.43.1                                                                     (git)-[master]
Installing the controlplane in quickstart mode...
Failed to install PipeCD control plane!!
github.com/pipe-cd/pipecd/pkg/app/pipectl/cmd/quickstart.(*command).run
	/home/runner/work/pipecd/pipecd/pkg/app/pipectl/cmd/quickstart/quickstart.go:114
github.com/pipe-cd/pipecd/pkg/cli.runWithContext
	/home/runner/work/pipecd/pipecd/pkg/cli/cmd.go:95
github.com/pipe-cd/pipecd/pkg/cli.WithContext.func1
	/home/runner/work/pipecd/pipecd/pkg/cli/cmd.go:51
github.com/spf13/cobra.(*Command).execute
	/home/runner/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:842
github.com/spf13/cobra.(*Command).ExecuteC
	/home/runner/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:950
github.com/spf13/cobra.(*Command).Execute
	/home/runner/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:887
github.com/pipe-cd/pipecd/pkg/cli.(*App).Run
	/home/runner/work/pipecd/pipecd/pkg/cli/app.go:60
main.main
	/home/runner/work/pipecd/pipecd/cmd/pipectl/main.go:47
runtime.main
	/opt/hostedtoolcache/go/1.19.3/x64/src/runtime/proc.go:250
Usage:
  pipectl quickstart [flags]

Flags:
  -h, --help               help for quickstart
      --namespace string   The Kubernetes cluster namespace where to install Control Plane. (default "pipecd")
      --tools-dir string   The path to directory where to install tools such as helm. (default "/Users/s14218/.pipectl/tools")
      --uninstall          Uninstall the quickstart mode installed PipeCD control plane.
      --version string     The Control Plane version. Default is the version of pipectl. (default "v0.43.1")

Global Flags:
      --log-encoding string                The encoding type for logger [json|console|humanize]. (default "humanize")
      --log-level string                   The minimum enabled logging level. (default "info")
      --metrics                            Whether metrics is enabled or not. (default true)
      --profile                            If true enables uploading the profiles to Stackdriver.
      --profile-debug-logging              If true enables logging debug information of profiler.
      --profiler-credentials-file string   The path to the credentials file using while sending profiles to Stackdriver.

Error: exit status 1: Error: Kubernetes cluster unreachable: Get "https://127.0.0.1:50668/version": dial tcp 127.0.0.1:50668: connect: connection refused

This is because usage is shown before cli handles error on app.Run().
By default, cobra shows usage when command.Execute(). ref: the internal of it

[ffjlabo]

In this comment on the cobra's issue, it is suggested to disable showing usage by default, and show it only when flag parsing fails. So how would you like to fix like this?

[ffjlabo]

FYI, this is draft fix ffjlabo@d395ee3.

when parsing fails

% .artifacts/pipectl quickstart --versio v0.43.1                                (git)-[show-usage-only-when-parsing-err]
unknown flag: --versio
Usage:
  pipectl quickstart [flags]

Flags:
  -h, --help               help for quickstart
      --namespace string   The Kubernetes cluster namespace where to install Control Plane. (default "pipecd")
      --tools-dir string   The path to directory where to install tools such as helm. (default "/Users/s14218/.pipectl/tools")
      --uninstall          Uninstall the quickstart mode installed PipeCD control plane.
      --version string     The Control Plane version. Default is the version of pipectl. (default "v0.25.1-870-gd395ee3")

Global Flags:
      --log-encoding string                The encoding type for logger [json|console|humanize]. (default "humanize")
      --log-level string                   The minimum enabled logging level. (default "info")
      --metrics                            Whether metrics is enabled or not. (default true)
      --profile                            If true enables uploading the profiles to Stackdriver.
      --profile-debug-logging              If true enables logging debug information of profiler.
      --profiler-credentials-file string   The path to the credentials file using while sending profiles to Stackdriver.

Error: FlagParseErr

when internal errors

% .artifacts/pipectl quickstart --version v0.43.1                               (git)-[show-usage-only-when-parsing-err]
Installing the controlplane in quickstart mode...
Failed to install PipeCD control plane!!
github.com/pipe-cd/pipecd/pkg/app/pipectl/cmd/quickstart.(*command).run
	/Users/s14218/works/ffjlabo/pipecd/pkg/app/pipectl/cmd/quickstart/quickstart.go:114
github.com/pipe-cd/pipecd/pkg/cli.runWithContext
	/Users/s14218/works/ffjlabo/pipecd/pkg/cli/cmd.go:95
github.com/pipe-cd/pipecd/pkg/cli.WithContext.func1
	/Users/s14218/works/ffjlabo/pipecd/pkg/cli/cmd.go:51
github.com/spf13/cobra.(*Command).execute
	/Users/s14218/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:842
github.com/spf13/cobra.(*Command).ExecuteC
	/Users/s14218/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:950
github.com/spf13/cobra.(*Command).Execute
	/Users/s14218/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:887
github.com/pipe-cd/pipecd/pkg/cli.(*App).Run
	/Users/s14218/works/ffjlabo/pipecd/pkg/cli/app.go:69
main.main
	/Users/s14218/works/ffjlabo/pipecd/cmd/pipectl/main.go:47
runtime.main
	/opt/homebrew/Cellar/go/1.20.3/libexec/src/runtime/proc.go:250
Error: exit status 1: Error: Kubernetes cluster unreachable: Get "https://127.0.0.1:50668/version": dial tcp 127.0.0.1:50668: connect: connection refused

[khanhtc1202]

Nice, could you commit the fix 🙏 And welcome back @ffjlabo 🙌

[ffjlabo]

It's been a while @khanhtc1202 san!
Thank you! I'll make a PR 👍

Oh...I forgot to tell one thing.
Is it OK that fix affects not only pipectl but also any other clis using cli.NewApp?

[khanhtc1202]

@ffjlabo For sure if you think it's the better choice 😄

[khanhtc1202]

@ffjlabo Hi there, any update on this? If possible, we would like to add this to the next release (v0.44.2) Please lets me know if you want some help 😄

[ffjlabo]

@khanhtc1202 Sorry to be late. I forgot to make a PR 🙇
Soon I make it!