Refactored daemon base API: added Logger.

src/sonic-daemon-base/sonic_daemon_base/daemon_base.py

@@ -4,82 +4,111 @@
     import imp
     import signal
     import subprocess
+    import os
     import sys
     import syslog
     from swsscommon import swsscommon
 except ImportError, e:
     raise ImportError (str(e) + " - required module not found")
 
-#============================= Constants =============================
+#
+# Constants ====================================================================
+#
+
+# Redis DB information
+REDIS_HOSTNAME = 'localhost'
+REDIS_PORT = 6379
+REDIS_TIMEOUT_MSECS = 0
 
 # Platform root directory inside docker
-PLATFORM_ROOT_DOCKER = "/usr/share/sonic/platform"
+PLATFORM_ROOT_DOCKER = '/usr/share/sonic/platform'
 SONIC_CFGGEN_PATH = '/usr/local/bin/sonic-cfggen'
 HWSKU_KEY = 'DEVICE_METADATA.localhost.hwsku'
 PLATFORM_KEY = 'DEVICE_METADATA.localhost.platform'
 
+# Port config information
+PORT_CONFIG = 'port_config.ini'
+PORTMAP = 'portmap.ini'
+
 EEPROM_MODULE_NAME = 'eeprom'
 EEPROM_CLASS_NAME = 'board'
 
-class DaemonBase(object):
-    # Redis DB information
-    redis_hostname = "localhost"
-    redis_port = 6379
-    redis_timeout_msecs = 0
+#
+# Helper functions =============================================================
+#
 
-    def __init__(self):
-        self.log_info("Starting up...")
-        # Register our signal handlers
-        signal.signal(signal.SIGHUP, self.signal_handler)
-        signal.signal(signal.SIGINT, self.signal_handler)
-        signal.signal(signal.SIGTERM, self.signal_handler)
+def db_connect(db):
+    return swsscommon.DBConnector(db,
+                                  REDIS_HOSTNAME,
+                                  REDIS_PORT,
+                                  REDIS_TIMEOUT_MSECS)
+
+#
+# Helper classes ===============================================================
+#
+
+class Logger(object):
+    def __init__(self, syslog_identifier):
+        syslog.openlog(ident=syslog_identifier, logoption=syslog.LOG_NDELAY, facility=syslog.LOG_DAEMON)
 
     def __del__(self):
-        self.log_error("Return from daemon, exiting...")
+        syslog.closelog()
 
-    def run(self):
-        raise NotImplementedError()
+    def log_error(self, msg, also_print_to_console=False):
+        syslog.syslog(syslog.LOG_ERR, msg)
+
+        if also_print_to_console:
+            print msg
 
-    # ========================== Connect to DB ============================
-    def db_connect(self, db):
-        return swsscommon.DBConnector(db,
-                                      self.redis_hostname,
-                                      self.redis_port,
-                                      self.redis_timeout_msecs)
+    def log_warning(self, msg, also_print_to_console=False):
+        syslog.syslog(syslog.LOG_WARNING, msg)
+
+        if also_print_to_console:
+            print msg
+
+    def log_notice(self, msg, also_print_to_console=False):
+        syslog.syslog(syslog.LOG_NOTICE, msg)
 
-    # ========================== Syslog wrappers ==========================
-    def log_info(self, msg):
-        syslog.openlog()
+        if also_print_to_console:
+            print msg
+
+    def log_info(self, msg, also_print_to_console=False):
         syslog.syslog(syslog.LOG_INFO, msg)
-        syslog.closelog()
 
-    def log_warning(self, msg):
-        syslog.openlog()
-        syslog.syslog(syslog.LOG_WARNING, msg)
-        syslog.closelog()
+        if also_print_to_console:
+            print msg
 
-    def log_error(self, msg):
-        syslog.openlog()
-        syslog.syslog(syslog.LOG_ERR, msg)
-        syslog.closelog()
+    def log_debug(self, msg, also_print_to_console=False):
+        syslog.syslog(syslog.LOG_DEBUG, msg)
+
+        if also_print_to_console:
+            print msg
 
-    #========================== Signal Handling ==========================
+#
+# Daemon =======================================================================
+#
+
+class DaemonBase(object):
+    def __init__(self):
+        # Register our signal handlers
+        signal.signal(signal.SIGHUP, self.signal_handler)
+        signal.signal(signal.SIGINT, self.signal_handler)
+        signal.signal(signal.SIGTERM, self.signal_handler)
+
+    # Signal handler
     def signal_handler(self, sig, frame):
         if sig == signal.SIGHUP:
-            self.log_info("Caught SIGHUP - ignoring...")
-            return
+            syslog.syslog(syslog.LOG_INFO, "Caught SIGHUP - ignoring...")
         elif sig == signal.SIGINT:
-            self.log_info("Caught SIGINT - exiting...")
+            syslog.syslog(syslog.LOG_INFO, "Caught SIGINT - exiting...")
             sys.exit(128 + sig)
         elif sig == signal.SIGTERM:
-            self.log_info("Caught SIGTERM - exiting...")
+            syslog.syslog(syslog.LOG_INFO, "Caught SIGTERM - exiting...")
             sys.exit(128 + sig)
         else:
-            self.log_warning("Caught unhandled signal '" + sig + "'")
-            return
+            syslog.syslog(syslog.LOG_WARNING, "Caught unhandled signal '" + sig + "'")
 
-    #============ Functions to load platform-specific classes ============
-    # Returns platform and HW SKU
+    # Returns platform and hwsku
     def get_platform_and_hwsku(self):
         try:
             proc = subprocess.Popen([SONIC_CFGGEN_PATH, '-H', '-v', PLATFORM_KEY],
@@ -98,12 +127,11 @@ def get_platform_and_hwsku(self):
             proc.wait()
             hwsku = stdout.rstrip('\n')
         except OSError, e:
-            self.log_error("Cannot to detect platform")
-            raise OSError("Cannot detect platform")
+            raise OSError("Failed to detect platform: %s" % (str(e)))
 
         return (platform, hwsku)
 
-    # Returns path to hwsku
+    # Returns path to platform and hwsku
     def get_path_to_platform_and_hwsku(self):
         # Get platform and hwsku
         (platform, hwsku) = self.get_platform_and_hwsku()
@@ -114,6 +142,21 @@ def get_path_to_platform_and_hwsku(self):
 
         return (platform_path, hwsku_path)
 
+    # Returns path to port config file
+    def get_path_to_port_config_file(self):
+        # Get platform and hwsku path
+        (platform_path, hwsku_path) = self.get_path_to_platform_and_hwsku()
+
+        # First check for the presence of the new 'port_config.ini' file
+        port_config_file_path = "/".join([hwsku_path, PORT_CONFIG])
+        if not os.path.isfile(port_config_file_path):
+            # port_config.ini doesn't exist. Try loading the legacy 'portmap.ini' file
+            port_config_file_path = "/".join([hwsku_path, PORTMAP])
+            if not os.path.isfile(port_config_file_path):
+                raise IOError("Failed to detect port config file: %s" % (port_config_file_path))
+
+        return port_config_file_path
+
     # Loads platform specific psuutil module from source
     def load_platform_util(self, module_name, class_name):
         platform_util = None
@@ -125,8 +168,7 @@ def load_platform_util(self, module_name, class_name):
             module_file = "/".join([platform_path, "plugins", module_name + ".py"])
             module = imp.load_source(module_name, module_file)
         except IOError, e:
-            self.log_error("Failed to load platform module '%s': %s" % (module_name, str(e)))
-            return None
+            raise IOError("Failed to load platform module '%s': %s" % (module_name, str(e)))
 
         try:
             platform_util_class = getattr(module, class_name)
@@ -136,8 +178,10 @@ def load_platform_util(self, module_name, class_name):
             else:
                 platform_util = platform_util_class()
         except AttributeError, e:
-            self.log_error("Failed to instantiate '%s' class: %s" % (class_name, str(e)))
-            return None
+            raise AttributeError("Failed to instantiate '%s' class: %s" % (class_name, str(e)))
 
         return platform_util
 
+    # Runs daemon
+    def run(self):
+        raise NotImplementedError()