#1065 Use logging module instead of syslog

We can't use syslog if we want to execute ogClient in the Windows
platform.

Use the native logging library so we can attach different handlers
depending on the mode ogClient is executing.

Logging configuration is done via a python dict. There is a different
dict for linux and windows. These dicts define the configuration of the
root logger, handlers and formatters used.

As of now, it is only expected to use the root logger for everything
logging related. The root logger is obtained via:

	LOGGER = logging.getLogger()

More info about handlers, formatters and loggers:
	https://docs.python.org/3/howto/logging.html

Logging configuration is done at startup, just after parsing the json
(knowing ogclient mode). If json parsing goes bad, ogclient will only
print a message to stdout.

3 files changed, 88 insertions, 14 deletions

diff --git a/ogclient b/ogclient
index 528a0e4..4f8ca56 100755
--- a/ogclient
+++ b/ogclient
@@ -18,6 +18,7 @@ except ImportError:
 
 
 from src.ogClient import *
+from src.log import configure_logging
 
 
 def main():
@@ -36,6 +37,8 @@ def main():
 	if MODE != 'windows':
 		signal.signal(SIGPIPE, SIG_DFL)
 
+	configure_logging(MODE)
+
 	client = ogClient(config=CONFIG)
 	client.connect()
 	client.run()
diff --git a/src/log.py b/src/log.py
new file mode 100644
index 0000000..9d379eb
--- /dev/null
+++ b/src/log.py
@@ -0,0 +1,72 @@
+import logging
+import logging.config
+
+DEFAULT_LOGGING_LINUX = {
+    'version': 1,
+    'disable_existing_loggers': False,
+    'formatters': {
+        'formatter.syslog': {
+            '()': 'logging.Formatter',
+            'format': 'ogClient: [{levelname}] - {message}',
+            'style': '{',
+        },
+        'formatter.console': {
+            '()': 'logging.Formatter',
+            'format': '[{levelname}] - {message}',
+            'style': '{',
+        },
+    },
+    'handlers': {
+        'console': {
+            'level': 'INFO',
+            'class': 'logging.StreamHandler',
+            'formatter': 'formatter.console',
+            'stream': 'ext://sys.stdout',
+        },
+        'syslog': {
+            'level': 'DEBUG',
+            'class': 'logging.handlers.SysLogHandler',
+            'formatter': 'formatter.syslog',
+            'address': '/dev/log',
+        },
+    },
+    'loggers': {
+        '': {
+            'handlers': ['syslog', 'console'],
+            'level': 'DEBUG',
+        },
+    }
+}
+
+DEFAULT_LOGGING_WIN = {
+    'version': 1,
+    'disable_existing_loggers': False,
+    'formatters': {
+        'formatter.console': {
+            '()': 'logging.Formatter',
+            'format': 'ogClient: [{levelname}] - {message}',
+            'style': '{',
+        }
+    },
+    'handlers': {
+        'console': {
+            'level': 'DEBUG',
+            'class': 'logging.StreamHandler',
+            'formatter': 'formatter.console',
+            'stream': 'ext://sys.stdout',
+        },
+    },
+    'loggers': {
+        '': {
+            'handlers': ['console'],
+            'level': 'DEBUG',
+        },
+    }
+}
+
+def configure_logging(mode):
+    if mode == 'windows':
+        DEFAULT_LOGGING = DEFAULT_LOGGING_WIN
+    else:
+        DEFAULT_LOGGING = DEFAULT_LOGGING_LINUX
+    logging.config.dictConfig(DEFAULT_LOGGING)
diff --git a/src/ogRest.py b/src/ogRest.py
index 0d8ff87..954b2be 100644
--- a/src/ogRest.py
+++ b/src/ogRest.py
@@ -16,9 +16,13 @@ import sys
 import os
 import signal
 import syslog
+import logging
+from logging.handlers import SysLogHandler
 
 from src.restRequest import *
 
+LOGGER = logging.getLogger()
+
 class ThreadState(Enum):
 	IDLE = 0
 	BUSY = 1
@@ -55,11 +59,9 @@ class restResponse():
 			return self.msg
 
 		if response in {ogResponses.OK, ogResponses.IN_PROGRESS}:
-			syslog.syslog(syslog.LOG_INFO,
-				      self.msg[:ogRest.LOG_LENGTH])
+			LOGGER.info(self.msg[:ogRest.LOG_LENGTH])
 		else:
-			syslog.syslog(syslog.LOG_ERR,
-				      self.msg[:ogRest.LOG_LENGTH])
+			LOGGER.warn(self.msg[:ogRest.LOG_LENGTH])
 
 		self.msg += '\r\n'
 
@@ -274,16 +276,15 @@ class ogRest():
 		method = request.get_method()
 		URI = request.get_uri()
 
-		syslog.syslog(syslog.LOG_DEBUG, f'{method}{URI[:ogRest.LOG_LENGTH]}')
+		LOGGER.debug('%s%s', method, URI[:ogRest.LOG_LENGTH])
 
 		if (not "stop" in URI and
 		    not "reboot" in URI and
 		    not "poweroff" in URI and
 		    not "probe" in URI):
 			if self.state == ThreadState.BUSY:
-				syslog.syslog(syslog.LOG_ERR,
-					      'Request has been received '
-					      'while ogClient is busy')
+				LOGGER.warn('Request has been received '
+					    'while ogClient is busy')
 				response = restResponse(ogResponses.SERVICE_UNAVAILABLE)
 				client.send(response.get())
 				return
@@ -300,9 +301,8 @@ class ogRest():
 			elif "refresh" in URI:
 				self.process_refresh(client)
 			else:
-				syslog.syslog(syslog.LOG_ERR,
-					      f'Unsupported request: '
-					      f'{method[:ogRest.LOG_LENGTH]}')
+				LOGGER.warn('Unsupported request: %s',
+					    {URI[:ogRest.LOG_LENGTH]})
 				response = restResponse(ogResponses.BAD_REQUEST)
 				client.send(response.get())
 				self.state = ThreadState.IDLE
@@ -326,9 +326,8 @@ class ogRest():
 			elif ("image/create" in URI):
 				self.process_imagecreate(client, request)
 			else:
-				syslog.syslog(syslog.LOG_ERR,
-					      f'Unsupported request: '
-					      f'{method[:ogRest.LOG_LENGTH]}')
+				LOGGER.warn('Unsupported request: %s',
+					    URI[:ogRest.LOG_LENGTH])
 				response = restResponse(ogResponses.BAD_REQUEST)
 				client.send(response.get())
 				self.state = ThreadState.IDLE