CODEWITHSUNDEEP
spring-cloudspring-cloud-gateway
Parameswaran V V
Parameswaran V V

Reputation: 21

How can we conditionally route to a different URL in Spring Cloud Gateway? Is there a reference sample?

Trying to change the exchange target URL conditionally. Is there a way this can be achieved in Spring Cloud Gateway?

To elaborate, upon inspecting a particular cookie value in the incoming request, I would like to route it to a different URL.

Upvotes: 2

Views: 2121

Answers (1)

spencergibb
spencergibb

Reputation: 25177

We do something similar with request headers here. We have an abstract filter that handles setting the uri correctly, you just have to determine the uri from the ServerWebExchange.

public class CookieToRequestUriGatewayFilterFactory extends
        AbstractChangeRequestUriGatewayFilterFactory<AbstractGatewayFilterFactory.NameConfig> {
    private final Logger log = LoggerFactory
            .getLogger(RequestHeaderToRequestUriGatewayFilterFactory.class);

    public RequestHeaderToRequestUriGatewayFilterFactory() {
        super(NameConfig.class);
    }

    @Override
    public List<String> shortcutFieldOrder() {
        return Arrays.asList(NAME_KEY);
    }

    @Override
    protected Optional<URI> determineRequestUri(ServerWebExchange exchange,
            NameConfig config) {
        String cookieValue = exchange.getRequest().getCookies().getFirst(config.getName());
        String requestUrl = determineUrlFromCookie(cookieValue);
        return Optional.ofNullable(requestUrl).map(url -> {
            try {
                return new URL(url).toURI();
            }
            catch (MalformedURLException | URISyntaxException e) {
                log.info("Request url is invalid : url={}, error={}", requestUrl,
                        e.getMessage());
                return null;
            }
        });
    }
}

It would be up to you to implement determineUrlFromCookie().

Upvotes: 2

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