feat: add a remote non-finalised log file getter from Tornado

Author: martynia

src/DIRAC/WorkloadManagementSystem/Client/PilotLoggingPlugins/FileCacheLoggingPlugin.py

@@ -104,6 +104,26 @@ def getMeta(self):
             return S_OK(self.meta)
         return S_ERROR("No Pilot logging directory defined")
 
+    def getLogs(self, logfile, vo):
+        """
+        Get the "instant" logs from Tornado log storage area. There are not finalised (incomplete) logs.
+
+        :return:  Dirac S_OK containing the logs
+        :rtype: dict
+        """
+
+        filename = os.path.join(self.meta["LogPath"], vo, logfile)
+        resultDict = {}
+        try:
+            with open(filename) as f:
+                stdout = f.read()
+                resultDict["StdOut"] = stdout
+        except FileNotFoundError as err:
+            sLog.error(f"Error opening a log file:{filename}", err)
+            return S_ERROR(repr(err))
+
+        return S_OK(resultDict)
+
     def _verifyUUIDPattern(self, logfile):
         """
         Verify if the name of the log file matches the required pattern.

src/DIRAC/WorkloadManagementSystem/Service/TornadoPilotLoggingHandler.py

@@ -80,6 +80,16 @@ def export_getMetadata(self):
         """
         return self.loggingPlugin.getMeta()
 
+    def export_getLogs(self, logfile, vo):
+        """
+        Get (not yet finalised) logs from the server.
+
+        :return:  S_OK containing a metadata dictionary
+        :rtype: dict
+        """
+
+        return self.loggingPlugin.getLogs(logfile, vo)
+
     def export_finaliseLogs(self, payload, pilotUUID):
         """
         Finalise a log file. Finalised logfile can be copied to a secure location, if a file cache is used.