fix bug:correct handle when meets PermissionError (#460)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **Bug Fixes**
  - Improved log file path creation logic to enhance reliability.
  - Added detailed log messages for file initialization.
- Enhanced error handling for permission issues when creating log files.
  - Adjusted log handlers for better log management.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: felix5572

dpdispatcher/dlog.py

@@ -6,21 +6,25 @@
 dlog = logging.getLogger("dpdispatcher")
 dlog.propagate = False
 dlog.setLevel(logging.INFO)
+cwd_logfile_path = os.path.join(os.getcwd(), "dpdispatcher.log")
+dlogf = logging.FileHandler(cwd_logfile_path, delay=True)
 try:
-    dlogf = logging.FileHandler(
-        os.getcwd() + os.sep + "dpdispatcher" + ".log", delay=True
-    )
+    dlog.addHandler(dlogf)
+    dlog.info(f"LOG INIT:dpdispatcher log direct to {cwd_logfile_path}")
 except PermissionError:
+    dlog.removeHandler(dlogf)
     warnings.warn(
-        "dpdispatcher.log meet permission error. redirect the log to ~/dpdispatcher.log"
+        f"dump logfile dpdispatcher.log to {cwd_logfile_path} meet permission error. redirect the log to ~/dpdispatcher.log"
     )
     dlogf = logging.FileHandler(
         os.path.join(os.path.expanduser("~"), "dpdispatcher.log"), delay=True
     )
+    dlog.addHandler(dlogf)
+    dlog.info("LOG INIT:dpdispatcher log init at ~/dpdispatcher.log")
 
 dlogf_formatter = logging.Formatter("%(asctime)s - %(levelname)s : %(message)s")
 dlogf.setFormatter(dlogf_formatter)
-dlog.addHandler(dlogf)
+# dlog.addHandler(dlogf)
 
 dlog_stdout = logging.StreamHandler(sys.stdout)
 dlog_stdout.setFormatter(dlogf_formatter)