Request and Response Header Instrumentation

The DGS framework internally uses GraphQL Java and Spring for GraphQL.

If you need to modify the HTTP request and response headers, you can leverage the WebGraphQlInterceptor in Spring for GraphQL to accomplish this. This provides a hook to update the request and response headers based using the GraphQLContext

Example:

@Component
public class MyInterceptor implements WebGraphQlInterceptor {
    @Override
    public Mono<WebGraphQlResponse> intercept(WebGraphQlRequest request, Chain chain) {
        String value = request.getHeaders().getFirst("myHeader");
        request.configureExecutionInput((executionInput, builder) ->
                builder.graphQLContext(Collections.singletonMap("myHeader", value)).build());
        return chain.next(request).doOnNext((response) -> {
            String value = response.getExecutionInput().getGraphQLContext().get("myContext");
            response.getResponseHeaders().add("MyContext", value);
        });
    }
}