Add documentation to dirac endpoint : Closes #3971

lib/rucio/web/rest/flaskapi/v1/dirac.py

@@ -38,17 +38,25 @@ class AddFiles(MethodView):
 
     def post(self):
         """
-        Create file replicas at a given RSE.
+        Atomic method used by the RucioFileCatalog plugin in Dirac that :
+        - Creates files and their replicas
+        - Creates the dataset containing the files and attach the files to the dataset
+        - Creates a rule on the dataset with RSE expression ANY and grouping NONE
+        - Creates all the container hierarchy containing the dataset
 
-        HTTP Success:
-            201 Created
+        ..:quickref: AddFiles; Method used by the RucioFileCatalog plugin in Dirac.
 
-        HTTP Error:
-            401 Unauthorized
-            405 Method Not Allowed
-            409 Conflict
-            500 Internal Error
-            503 Service Unavailable
+        :<json list lfns: List of lfn (dictionary {'lfn': <lfn>, 'rse': <rse>, 'bytes': <bytes>, 'adler32': <adler32>, 'guid': <guid>, 'pfn': <pfn>}.
+        :<json bool ignore_availability: A boolean to choose if unavailable sites need to be ignored.
+
+        :status 201: Created.
+        :status 400: Cannot decode json parameter list.
+        :status 401: Invalid auth token.
+        :status 404: DID not found.
+        :status 405: Unsupported Operation.
+        :status 409: Duplicate.
+        :status 500: Internal Error.
+        :status 503: Temporary error.
         """
         try:
             parameters = parse_response(request.data)