How to include JSON response body in Spring Boot Actuator's Trace?
Recently, I wrote a blog post about customization of Spring Boot Actuator's trace
endpoint and while playing with Actuator, I was kinda surprised that response body
isn't one of the supported properties to trace.
I thought I may need this feature and came up with a quick solution thanks to Logback's TeeFilter
.
To duplicate output stream of the response, I copied and used TeeHttpServletResponse and TeeServletOutputStream without too much examination.
Then, just like I explained in the blog post, extended WebRequestTraceFilter
like:
@Component
public class RequestTraceFilter extends WebRequestTraceFilter {
RequestTraceFilter(TraceRepository repository, TraceProperties properties) {
super(repository, properties);
}
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
TeeHttpServletResponse teeResponse = new TeeHttpServletResponse(response);
filterChain.doFilter(request, teeResponse);
teeResponse.finish();
request.setAttribute("responseBody", teeResponse.getOutputBuffer());
super.doFilterInternal(request, teeResponse, filterChain);
}
@Override
protected Map<String, Object> getTrace(HttpServletRequest request) {
Map<String, Object> trace = super.getTrace(request);
byte[] outputBuffer = (byte[]) request.getAttribute("responseBody");
if (outputBuffer != null) {
trace.put("responseBody", new String(outputBuffer));
}
return trace;
}
}
Now, you can see responseBody
in the JSON trace
endpoint serves.