undefined: when on an endpoint, this denotes that the endpoint defers origin checks to the
parent service's origin requirement. When on the service, undefined is not allowed.
string: require all request origins to exactly match the given string.
RegExp: all request origins must match the RegExp.
A function: allow custom checking. If this function returns something truthy, the origin is
allowed.
An array: a combination of string values, RegExp values, or functions to compare against. If
any of the array entries allow a request origin, it passes.
Options explained:
undefined: when on an endpoint, this denotes that the endpoint defers origin checks to the parent service's origin requirement. When on the service,undefinedis not allowed.string: require all request origins to exactly match the given string.RegExp: all request origins must match the RegExp.stringvalues,RegExpvalues, or functions to compare against. If any of the array entries allow a request origin, it passes.