feat: As a user, I want to hide 5xx error detail from the client, so that the detail is not leaked

[spacewander]

Description

For example,

apisix/apisix/plugins/authz-keycloak.lua

Lines 664 to 666 in a1482dd

	err = "Error while sending authz request to " .. token_endpoint .. ": " .. err
	log.error(err)
	return 500, err

will tell the client about the token endpoint configuration.

[liangliang4ward]

you mean hiding real err to client ？
like

return 500,"error client balala"

[spacewander]

Yes, we can just return 503. Like this one: #6382 (comment)

[liangliang4ward]

let me check and modify them.