Add a warning for disallowed email domains

[Zettat123]

Resolve #29660

Follow #29522 and #29609

Add a warning for disallowed email domains when admins manually add/edit users.

Thanks @yp05327 for the comment

[lunny]

related to #29660?

[yp05327]

My suggestion:
The user email domain %s is not listed in EMAIL_DOMAIN_ALLOWLIST. Please ensure your operation is expected.

ps: does other options effect it? e.g. something like email domain not allowed.
ps: is it possible to add warning in the API? 🤔

[Zettat123]

ps: does other options effect it?

Yes. EMAIL_DOMAIN_BLOCKLIST also affects.

Maybe The user email domain %s conflicts with EMAIL_DOMAIN_ALLOWLIST or EMAIL_DOMAIN_BLOCKLIST. Please ensure your operation is expected. ?

[Zettat123]

ps: is it possible to add warning in the API?

Not sure how to add the warning to the API. Maybe something like this?

gitea/routers/api/v1/repo/repo.go

Lines 1190 to 1192 in 9dc8a63

	if cnt := len(ret.TemplateErrors); cnt != 0 {
	ctx.Resp.Header().Add("X-Gitea-Warning", "error occurs when parsing issue template: count="+strconv.Itoa(cnt))
	}

[yp05327]

ps: is it possible to add warning in the API?

Not sure how to add the warning to the API. Maybe something like this?

gitea/routers/api/v1/repo/repo.go

Lines 1190 to 1192 in 9dc8a63

	if cnt := len(ret.TemplateErrors); cnt != 0 {
	ctx.Resp.Header().Add("X-Gitea-Warning", "error occurs when parsing issue template: count="+strconv.Itoa(cnt))
	}

Searched a lot, and normally there are three solutions:

• some Apps are using http status code 299 as a warning http status code.
• there's a Warning header, but it is deprecated:
  https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Warning
• add warnings in JSON body. It is impossible for Gitea, as we are using http status code as the result, but not adding status in JSON body.

It seems that there's no normal rules.

[Zettat123]

some Apps are using http status code 299 as a warning http status code.

Looks like 299 is not an official code. Since Gitea is already using X-Gitea-Warning to indicate warning messages, I think we can also use it for now

[yp05327]

Since Gitea is already using X-Gitea-Warning to indicate warning messages

Thanks for your notification. I didn't notice that.