Add cli flag --version to show version of spanner-cli

[kyu08]

Hello. Thank you for maintaining very useful cli for spanner!

What

SSIA

Why

It is more useful for troubleshooting if spanner-cli can show its version.

Implementation

I intentionally added Version to spannerOptions, though it might be not good idea to do so because it seems that --version is not a option to execute spanner-cli, but a kind of sub-command.

The reason why I did so is that I feel it is difficult to show description of --version if I don't add Version to spannerOptions.

As an alternative, I considered to parse os.Args like below. But as I mentioned above it it difficult to show description of --version when spanner-cli --help is executed.

	if len(os.Args) == 2 && os.Args[1] == "--version" {
		fmt.Fprintf(os.Stdout, "%s\n", versionInfo())
		os.Exit(0)
	}

Please give me your opinion.

[yfuruyama]

Thank you for sending this PR.

[yfuruyama]

Does this work? It looks like info.Main.Version still always returns (devel)...? https://groups.google.com/g/golang-nuts/c/ObM-ilI7sio

[kyu08]

Thanks for reviewing.🙏

This way is used by yo and wrench and they return their version properly.

It seems that it shows the valid version when it is released or installed via go install but I don't understand its mechanism. I'll look into it later.

[apstndb]

FYI: I believe it should be only valid in go install with tags.
Released binary should use another mechanism like LDFLAGS. (spanner-cli recently don't have release binaries).

I think you all are Japanese so I introduce this article.
https://rhysd.hatenablog.com/entry/2021/06/27/222254

[yfuruyama]

Oh I didn't know that. Then maybe we can merge this PR and see how it goes.

[yfuruyama]

It looks like pkg.go.dev correctly recognizes the version of spanner-cli from git tag: https://pkg.go.dev/github.com/cloudspannerecosystem/spanner-cli

FYI: I believe it should be only valid in go install with tags.

Do you mean go install github.com/cloudspannerecosystem/spanner-cli@latest always shows latest? Or does it show the git tag associated with the latest git commit?

[yfuruyama]

Thank you all for the information! The official installation of spanner-cli is go install as mentioned in README, so it looks like we don't need to manually embed the version information.

If it's fine, I'll go ahead and merge this PR.

[apstndb]

Do you mean go install github.com/cloudspannerecosystem/spanner-cli@latest always shows latest? Or does it show the git tag associated with the latest git commit?

Oh, that was not precise answer.
It always shows module version when go install-ed, so it can print version even if not tagged.(go install *@latest use latest released module version)

$ go install github.com/cloudspannerecosystem/wrench@9432313  
go: downloading github.com/cloudspannerecosystem/wrench v1.10.2-0.20241120031843-9432313f606f
$ wrench --version
v1.10.2-0.20241120031843-9432313f606f

$ go install github.com/cloudspannerecosystem/wrench@latest 
go: downloading github.com/cloudspannerecosystem/wrench v1.10.1
$ wrench --version
v1.10.1

[yfuruyama]

Thank you, sounds good.

[yfuruyama]

I merged the PR and put the tag v0.10.9: https://github.com/cloudspannerecosystem/spanner-cli/releases/tag/v0.10.9

[kyu08]

Thank you!