Refactor the compose build command flagging process

[Laitr0n]

There is no ideal about GlobalFlag(like namespace, address). I just refactor the compose build command.
Signed-off-by: Laitron meetlq@outlook.com

[Zheaoli]

Maybe you can update this pr after #1792 has been merged. I introduce a new global flag process helper function in #1792. it may help you

[Laitr0n]

Maybe you can update this pr after #1792 has been merged. I introduce a new global flag process helper function in #1792. it may help you

After merge pr #1793, Should we refactor

func NewClient(ctx context.Context, namespace, address string, opts ...containerd.ClientOpt) (*containerd.Client, context.Context, context.CancelFunc, error) 

to

func NewClient(commonOpts types.CommonOptions, GOptions * types.GlobalCommandOptions, opts ...containerd.ClientOpt) (*containerd.Client, context.Context, context.CancelFunc, error) 

first? Composer subcommand use this func many times, and maybe we refactor them one more time if not refactor it firstly.

[Zheaoli]

Maybe you can update this pr after #1792 has been merged. I introduce a new global flag process helper function in #1792. it may help you

After merge pr #1793, Should we refactor

func NewClient(ctx context.Context, namespace, address string, opts ...containerd.ClientOpt) (*containerd.Client, context.Context, context.CancelFunc, error) 

to

func NewClient(commonOpts types.CommonOptions, GOptions * types.GlobalCommandOptions, opts ...containerd.ClientOpt) (*containerd.Client, context.Context, context.CancelFunc, error) 

first? Composer subcommand use this func many times, and maybe we refactor them one more time if not refactor it firstly.

Nice catch, SGTM, I will make a PR tonight.

[djdongjin]

func NewClient(commonOpts types.CommonOptions, GOptions * types.GlobalCommandOptions, opts ...containerd.ClientOpt) (*containerd.Client, context.Context, context.CancelFunc, error) 

1. What is commonOpts types.CommonOptions?
2. If NewClient only needs 2 global flags namespace, address, I think it's fine passing the two instead of a whole GOptions * types.GlobalCommandOptions.

Meanwhile, for compose (sub)commands, a good start point is the getComposer function:

nerdctl/cmd/nerdctl/compose.go

Line 83 in 3e0fa4f

func getComposer(cmd *cobra.Command, client *containerd.Client) (*composer.Composer, error) {

It can be splitted into 2 sub functions:

1. getComposeOptions(cmd *cobra.Command) composer.Options that on the cmd side and construct the composer.Options from cmd. (basically, the first part of original function).
2. getComposer(opt composer.Options, client *containerd.Client, stdout, stderr io.Writer) (*composer.Composer, error) that on the pkg side and accept a compose option and stdout/stderr from cmd and construct the composer (the rest of original function).

[Laitr0n]

1. What is commonOpts types.CommonOptions?

2. If NewClient only needs 2 global flags namespace, address, I think it's fine passing the two instead of a whole GOptions * types.GlobalCommandOptions.

1. As you see, commonOpts types.CommonOptions come from PR [Refactor] Refactor the build subcommand flagging process #1792 which is outdated after you reviewed.
2. SGTM

Meanwhile, for compose (sub)commands, a good start point is the getComposer function:

nerdctl/cmd/nerdctl/compose.go

Line 83 in 3e0fa4f

func getComposer(cmd *cobra.Command, client *containerd.Client) (*composer.Composer, error) {

It can be splitted into 2 sub functions:

1. getComposeOptions(cmd *cobra.Command) composer.Options that on the cmd side and construct the composer.Options from cmd. (basically, the first part of original function).

2. getComposer(opt composer.Options, client *containerd.Client, stdout, stderr io.Writer) (*composer.Composer, error) that on the pkg side and accept a compose option and stdout/stderr from cmd and construct the composer (the rest of original function).

SGTM, I will finish this.