How to handle net errors in golang properly

I do not get how one can handle errors receiving from the net package. I need to know what kind of error occurred to do the next step. Trying to parse the error message string is probably not the right way...

response, err := data.httpClient.Get("https://" + domain)
if err != nil {				
	fmt.Println("[!] error: ", err)
    /* 
    *  I want something like this in pseudo code:
    *  if error == DnsLookupError {
    *      action1()
    *  } else if error == TlsCertificateError {
    *      action2()
    *  } else if error == Timeout {
    *      action3()
    *  } ...
    */
}

Error messages I receive for example:

Get "https://example1.com": remote error: tls: internal error
Get "https://example2.com": dial tcp: lookup example2.com
etc.

You can check whether the error is compatible with a few well-known error types. I did it like this:

func classifyNetworkError(err error) string {
	cause := err
	for {
		// Unwrap was added in Go 1.13.
		// See https://github.com/golang/go/issues/36781
		if unwrap, ok := cause.(interface{ Unwrap() error }); ok {
			cause = unwrap.Unwrap()
			continue
		}
		break
	}

	// DNSError.IsNotFound was added in Go 1.13.
	// See https://github.com/golang/go/issues/28635
	if cause, ok := cause.(*net.DNSError); ok && cause.Err == "no such host" {
		return "name not found"
	}

	if cause, ok := cause.(syscall.Errno); ok {
		if cause == 10061 || cause == syscall.ECONNREFUSED {
			return "connection refused"
		}
	}

	if cause, ok := cause.(net.Error); ok && cause.Timeout() {
		return "timeout"
	}

	return sprintf("unknown network error: %s", err)
}