From a8ab3abc569be4c11dd63a9c67e6f0964f53d4cf Mon Sep 17 00:00:00 2001
From: Adrian Vladu <avladu@cloudbasesolutions.com>
Date: Wed, 12 Apr 2017 20:40:49 +0300
Subject: [PATCH] Fixed infinite recursion when using serial ports

When using serial ports for logging, an infinite recursion occurs if the
serial port cannot be opened.

The solution is to add the serial port log handler only after the serial
port has been opened successfully.

Closes-bug: #1692888

Change-Id: Ifb2352292dd31869ee6d5ff83fe53584dd684ebd
---
 cloudbaseinit/utils/log.py | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/cloudbaseinit/utils/log.py b/cloudbaseinit/utils/log.py
index daace057..da4d9f42 100644
--- a/cloudbaseinit/utils/log.py
+++ b/cloudbaseinit/utils/log.py
@@ -52,23 +52,20 @@ class SerialPortHandler(logging.StreamHandler):
 
     def __init__(self):
         super(SerialPortHandler, self).__init__(None)
-        self.stream = None
+        self.stream = self._open()
 
     @staticmethod
     def _open():
         serial_port = None
         if CONF.logging_serial_port_settings:
             settings = CONF.logging_serial_port_settings.split(',')
-            try:
-                serial_port = serial.Serial(port=settings[0],
-                                            baudrate=int(settings[1]),
-                                            parity=settings[2],
-                                            bytesize=int(settings[3]))
-                if not serial_port.isOpen():
-                    serial_port.open()
-                serial_port.write = _safe_write(serial_port.write)
-            except serial.SerialException as exc:
-                LOG.debug(exc)
+            serial_port = serial.Serial(port=settings[0],
+                                        baudrate=int(settings[1]),
+                                        parity=settings[2],
+                                        bytesize=int(settings[3]))
+            if not serial_port.isOpen():
+                serial_port.open()
+            serial_port.write = _safe_write(serial_port.write)
         return serial_port
 
     def emit(self, record):
@@ -95,12 +92,15 @@ def setup(product_name):
     log.setup(CONF, product_name)
 
     if CONF.logging_serial_port_settings:
-        log_root = log.getLogger(product_name).logger
+        try:
+            serialportlog = SerialPortHandler()
+            log_root = log.getLogger(product_name).logger
+            log_root.addHandler(serialportlog)
 
-        serialportlog = SerialPortHandler()
-        log_root.addHandler(serialportlog)
-
-        datefmt = CONF.log_date_format
-        serialportlog.setFormatter(
-            formatters.ContextFormatter(project=product_name,
-                                        datefmt=datefmt))
+            datefmt = CONF.log_date_format
+            serialportlog.setFormatter(
+                formatters.ContextFormatter(project=product_name,
+                                            datefmt=datefmt))
+        except serial.SerialException:
+            LOG.warn("Serial port: {0} could not be opened".format(
+                     CONF.logging_serial_port_settings))