Improve logging on server

Log to file and std. Configured in server config file.

dsst/dsst_server/config.py

@@ -1,5 +1,6 @@
 # This config will be copied on first launch.
 # Edit the the copied file at '~/.config/dsst/server.json' before launching the server
+# IMPORTANT: For a client to access the server you have to set authentication tokens in the server config
 DEFAULT_CONFIG = {
     'database': {
         'db_name': 'dsst',
@@ -7,12 +8,38 @@ DEFAULT_CONFIG = {
         'password': 'dsst'
     },
     'server': {
-        'host': 'localhost',
         'port': 55225,
         'buffer_size': 1024
     },
     'tokens': {
-        '<read_write_token_here>': 'rw',
-        '<read_only_token_here>': 'r'
-    }
+        'readonly': [],
+        'readwrite': []
+    },
+    'logging': dict(
+        version=1,
+        disable_existing_loggers=False,
+        formatters={
+            'file': {'format': '[%(levelname)s] %(asctime)s - %(message)s',
+                     'datefmt': '%Y-%m-%d %H:%M:%S'},
+            'std': {'format': '[%(levelname)s] %(message)s'}
+        },
+        handlers={
+            'console': {
+                'class': 'logging.StreamHandler',
+                'formatter': 'std',
+                'level': 'INFO'
+            },
+            'logfile': {
+                'class': 'logging.handlers.RotatingFileHandler',
+                'maxBytes': 3145728,
+                'backupCount': 1,
+                'formatter': 'file',
+                'level': 'INFO'
+            }
+
+        },
+        root={
+            'handlers': ['console', 'logfile'],
+            'level': 'INFO'
+        })
 }

dsst/dsst_server/server.py

@@ -3,9 +3,11 @@ import pickle
 import socket
 import sys
 import os
+import logging
+from logging.config import dictConfig
 
-from common import util, models
-from dsst_server import func_read, func_write, auth
+from common import util
+from dsst_server import auth
 from dsst_server.func_proxy import FunctionProxy
 from dsst_server.data_access import sql, sql_func
 from dsst_server.config import DEFAULT_CONFIG
@@ -13,54 +15,63 @@ from dsst_server.config import DEFAULT_CONFIG
 
 class DsstServer:
     def __init__(self, config):
+        # Initialize the logger
+        try:
+            logger_dict = config.get('logging')
+            logfile = os.path.join(os.path.expanduser("~"), '.config', 'dsst', 'server.log')
+            logger_dict.get('handlers').get('logfile')['filename'] = logfile
+            dictConfig(logger_dict)
+        except Exception as e:
+            print(e)
+            sys.exit(1)
         self.socket_server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        print('Created socket')
+        logging.info('Created socket')
         server_conf = config.get('server')
         self.socket_server.bind(('', server_conf.get('port')))
-        print('Bound socket to port {}'.format(server_conf.get('port')))
+        logging.info('Bound socket to port {}'.format(server_conf.get('port')))
 
         # Initialize database
         db_config = config.get('database')
         sql.db.init(db_config.get('db_name'), user=db_config.get('user'), password=db_config.get('password'))
         sql_func.create_tables()
-        print('Database initialized ({})'.format(sql.db.database))
+        logging.info('Database initialized ({})'.format(sql.db.database))
 
         # Load access tokens
         auth.READ_TOKENS = config.get('tokens').get('readonly')
         auth.WRITE_TOKENS = config.get('tokens').get('readwrite')
-        print('Auth tokens loaded')
+        logging.info('Auth tokens loaded')
 
     def run(self):
         self.socket_server.listen(5)
-        print('Socket is listening')
+        logging.info('Socket is listening')
 
         while True:
             client, address = self.socket_server.accept()
             try:
-                print('Connection from {}'.format(address))
+                logging.info('Connection from {}'.format(address))
                 data = util.recv_msg(client)
                 request = pickle.loads(data)
-                print('Request: {}'.format(request))
+                logging.info('Request: {}'.format(request))
                 # Get requested function from function proxy
                 action_name = request.get('action')
                 action = getattr(FunctionProxy, action_name)
-                try:
-                    value = action(request.get('auth_token'), *request.get('args'))
-                except auth.AuthenticationError as e:
-                    response = e.get_response()
-                    util.send_msg(client, pickle.dumps(response))
-                    raise
-                except Exception as e:
-                    response = {'success': False, 'message': 'Exception was thrown on server.\n{}'.format(e)}
-                    util.send_msg(client, pickle.dumps(response))
-                    raise
+                # Execute requested function
+                value = action(request.get('auth_token'), *request.get('args'))
+                # Send results back to client
                 response = {'success': True, 'data': value}
                 util.send_msg(client, pickle.dumps(response))
+                logging.info('Operation executed successfully')
+            except auth.AuthenticationError as e:
+                logging.error(e.get_response())
+                response = e.get_response()
+                util.send_msg(client, pickle.dumps(response))
             except Exception as e:
-                print('Exception: ' + str(e))
+                logging.error('Exception was thrown: ' + str(e))
+                response = {'success': False, 'message': 'Exception was thrown on server.'}
+                util.send_msg(client, pickle.dumps(response))
             finally:
                 client.close()
-                print('Connection to client closed')
+                logging.info('Connection to client closed')
 
 
 def load_config(config_path: str) -> dict:
@@ -80,14 +91,16 @@ def main():
     config = os.path.join(os.path.expanduser('~'), '.config', 'dsst', 'server.json')
     if not os.path.isfile(config):
         save_config(DEFAULT_CONFIG, config)
-        print('No server config file found.\nCopied default config to "{}"\nPlease edit file before starting server.'
-              .format(config))
+        logging.error('No server config file found.\n'
+                      'Copied default config to "{}"\n'
+                      'Please edit file before starting server.'
+                      .format(config))
         sys.exit(0)
     server = DsstServer(load_config(config))
     try:
         server.run()
     except KeyboardInterrupt:
-        print('Server stopped')
+        logging.info('Server stopped')
         server.socket_server.close()
         try:
             sys.exit(0)