LoggingFilters

import org.apache.log4j.MDC

class LoggingFilters {

	public static final String CORRELATION_HEADER = "X-CorrelationId" //Our Standard

	def filters = {
		correlationId(controller: '*', action: '*') { //For all requests
			before = {
				String correlationId = request.getHeader(CORRELATION_HEADER)
				if (!correlationId) {
					correlationId = UUID.randomUUID()
					log.warn "message=CorrelationId does not exist along the request and hence autogenerated., CorrelationId=${correlationId}"
				}
				MDC.put 'correlationId', ", CorrelationId=${correlationId}"
				//If we still have an uncommited response which we should and no correlation header yet set one.
				if (!response.isCommitted() && !response.getHeader(CORRELATION_HEADER)) {
					response.setHeader(CORRELATION_HEADER, correlationId)
					//This header can be overridden by controller logic if needed
				}
			}
			after = { Map model ->
				MDC.remove 'correlationId'
			}
		}
	}
}