Base: Implement base classes for service management

1 files changed, 103 insertions, 0 deletions

diff --git a/ncserver/base/service.py b/ncserver/base/service.py
new file mode 100644
index 0000000..b16c8ad
--- /dev/null
+++ b/ncserver/base/service.py
@@ -0,0 +1,103 @@
+"""
+NETCONF for APK Distributions server:
+    Service management definitions and common routines.
+
+Copyright © 2020 Adélie Software in the Public Benefit, Inc.
+
+Released under the terms of the NCSA license.  See the LICENSE file included
+with this source distribution for more information.
+
+SPDX-License-Identifier: NCSA
+"""
+
+
+from abc import ABC, abstractmethod
+from enum import Enum
+
+
+class ServiceStatus(Enum):
+    """Represents the current status of a service."""
+    Stopped = 0
+    """The service is not presently running."""
+
+    Starting = 1
+    """The service is in the process of starting."""
+
+    Running = 2
+    """The service is presently running."""
+
+    Stopping = 3
+    """The service is in the process of stopping."""
+
+    Crashed = 4
+    """The service was running, but stopped unexpectedly."""
+
+
+class Service(ABC):
+    """Represents a service on the device.
+
+    This is an abstract base class.  You cannot use it directly; you must use
+    the service management module loaded to interact with services on the
+    device.
+    """
+
+    def __init__(self):
+        self._name = None
+        self._description = None
+        self._enabled = None
+        self._status = None
+        self._start_time = 0
+
+    @property
+    def name(self) -> str:
+        """Returns the name of the service."""
+        return self._name
+
+    @property
+    def description(self) -> str:
+        """Returns the description of the service."""
+        return self._description
+
+    @property
+    def enabled(self) -> bool:
+        """Returns whether the service is enabled."""
+        return self._enabled
+
+    @property
+    def status(self) -> ServiceStatus:
+        """Returns the current status of the service."""
+        return self._status
+
+    @property
+    def start_time(self) -> int:
+        """Returns the time the service was started.
+
+        Note: If the service is not running, this method returns 0.
+        """
+        return self._start_time
+
+    @abstractmethod
+    def start(self):
+        """Start the service."""
+
+    @abstractmethod
+    def stop(self):
+        """Stop the service."""
+
+    @abstractmethod
+    def reload(self):
+        """Tell the service to reload its configuration, if possible.
+
+        Not all services support this operation.  If the service does not
+        support this operation, it has no effect.
+        """
+
+    @abstractmethod
+    def restart(self, full: bool):
+        """Restart the service.
+
+        :param bool full:
+        Determine if this is a 'full' restart or not.  The meaning of a
+        full restart is defined by the service manager in use on the
+        device.
+        """