Polaris is not flexible and extensible enough to set metadata，I hope it can be set metadata through code

[yangjuanying]

Polaris is not flexible and extensible enough to set metadata here. This only through configuration “spring cloud.tencent.metadata” to set metadata. It is impossible to set metadata through code.

But Spring Cloud Consul and Nacos are flexible in this regard. For example, there is a customize method in the registration method of ConsulAutoRegistration

The user can implement the interface ConsulRegistrationCustomizer and put the customized metadata in the implementation class through code

It is suggested that Polaris should be modified like this in Class PolarisServiceRegistry.

[chuntaojun]

Okay, let's think about it here, and welcome to participate in the co-construction together to provide support for this ability~

[chuntaojun]

@SkyeBeFreeman what do you think

[SkyeBeFreeman]

It is a good idea to customize the metadata with code. I will add this enhancement later.

[lepdou]

@yangjuanying
I have add an SPI InstanceMetadataProvider in #244