additional tags for individual spans in fetch plugin

[nagarajatantry]

• [ x] This only affects the JavaScript OpenTelemetry library
• This may affect other libraries, but I would like to get opinions here first
  I am trying out the fetch plugin. I would like to add additional tags on some of the spans on need basis.

For example, in the below code snippet, i was trying to add additional tags based on url endpoints.

const getData = (url) => fetch(url, {
  method: 'GET',
  headers: {
    'Accept': 'application/json',
    'Content-Type': 'application/json',
  },
});

Reference --> https://github.com/open-telemetry/opentelemetry-js/blob/master/examples/tracer-web/examples/fetch/index.js#L32-L38

[dyladan]

I think you are looking for something similar to the http plugins's applyCustomAttributesOnSpan? https://github.com/open-telemetry/opentelemetry-js/blob/e93a86633bce5cc2ddeed4820adbcc5b60f88872/packages/opentelemetry-plugin-https/README.md#https-plugin-options

[obecny]

Can you please describe problem in more details as well as what would be the desired solution. Do you want to add static tags for each span or only some spans and if so how would you decide then which. Should those tags be static or dynamic (some callback needed for example) etc.