Using ThreadLocal in DGS

[pkadam1989]

I want to add incoming graphql request headers to Threadlocal.

Inside a datafetcher want to construct a RestTemplate client to reach out to another service with these headers. I want to register an interceptor for the RestTemplate which will read headers from ThreadLocal and add it to outgoing request.

Since DGS datafetcher executes on a different thread, I won't have access to the Threadlocal object set in filter.

Need suggestion on how we can achieve this? Any suggestions will be helpful

[berngp]

I would avoid using ThreadLocal to store information. You could use the DgsRequestData to get access to the request object and extract the headers as needed.

[pkadam1989]

Thank you for the quick response.
I was able to extract the headers using DgsRequestData.getHeaders() method in DataFetcher.
DgsRequestData requestData = DgsContext.getRequestData(dataFetchingEnvironment) HttpHeaders headers = requestData.getHeaders();

I want to do the same thing in rest template interceptor https://www.baeldung.com/spring-rest-template-interceptor.

How do I get access to the DataFetchingEnvironment object in my custom rest template interceptor?
So that interceptor could copy these headers for the new outbound request

[berngp]

You would inject the RestTemplate to the DgsComponent/Service implementing the DataFetcher and call it in the scope of the method that has access to the context/request data.

[pkadam1989]

I have implemented with same approach. But did not want to attach headers to each request in every DataFetcher method.
So was trying to see if I can copy request headers from the DGS context/request data in an interceptor on the RestTemplate which will be common for all outbound requests.