fix: stdoutJson logger prints all needed fields

Author: chaen

src/DIRAC/Resources/LogBackends/StdoutJsonBackend.py

@@ -8,12 +8,24 @@
 from DIRAC.FrameworkSystem.private.standardLogging.Formatter.MicrosecondJsonFormatter import MicrosecondJsonFormatter
 
 
+# These are the standard logging fields that we want to see
+# in the json. All the non default are printed anyway
+DEFAULT_FMT = "%(levelname)s %(message)s %(asctime)s"
+
+
 class StdoutJsonBackend(AbstractBackend):
     """
     This just spits out the log on stdout in a json format.
     """
 
     def __init__(self, backendParams=None, backendFilters=None):
+        # The `Format` parameter is passed as `fmt` to MicrosecondJsonFormatter
+        # which uses it to know which "standard" fields to keep in the
+        # json output. So we need these
+        if not backendParams:
+            backendParams = {}
+        backendParams.setdefault("Format", DEFAULT_FMT)
+
         super().__init__(logging.StreamHandler, MicrosecondJsonFormatter, backendParams, backendFilters)
 
     def _setHandlerParameters(self, backendParams=None):