support metric namespace

[Nicholaswang]

Description

support metric namespace option in config

Pull request type

Please check the type of change your PR introduces:

• Feature

Checklist

• Linter passes correctly
• Add tests which fail without the change (if possible)
• All tests passing
• Extended the README / documentation, if necessary

Does this introduce a breaking change?

• No

[sigua-cs]

IMO, this field can be configurable. This chproxy value can be the default. If someone needs to use a different value than the default, they will be able to set it in the config.

[Nicholaswang]

Actually, I agree with you. Would it be better to use another option MetricNamespace string?

[Nicholaswang]

Or providing EnableMetricNamespace bool and MetricNamespace string together?

[sigua-cs]

Yes. I think so

[Nicholaswang]

To confirm：
1）providing EnableMetricNamespace bool and MetricNamespace string combined
2) providing MetricNamespace string only
Which option do you prefer? @sigua-cs

[Nicholaswang]

adding Namespace string option in Server/Metrics struct

[sigua-cs]

Hello @Nicholaswang , I reviewed the PR and tested it locally. Looks good.
One more thing I would ask you to add. Please add to the testdata config example, which includes the namespace entity.

[Nicholaswang]

Hello @Nicholaswang , I reviewed the PR and tested it locally. Looks good. One more thing I would ask you to add. Please add to the testdata config example, which includes the namespace entity.

sure