NAPPS-968 | Adds device.install_mode to base driver and ios driver (#395)

* adds device.install_mode to base driver and ios driver

* pylint

* Updates per review

Author: jtdub

changes/395.added

@@ -0,0 +1 @@
+Added an ``install_mode`` property to ``BaseDevice`` (abstract) and ``IOSDevice``; the IOS implementation returns ``True`` when the device boots from ``packages.conf``.

changes/395.deprecated

@@ -0,0 +1 @@
+Deprecated the ``install_mode`` argument to ``IOSDevice.install_os``; install mode is now derived from the device's ``boot_options`` via the new ``install_mode`` property and will be removed in a future release.

pyntc/devices/base_device.py

@@ -450,6 +450,20 @@ def verify_file(self, checksum, filename, hashing_algorithm="md5", **kwargs):
         """
         raise NotImplementedError
 
+    @property
+    def install_mode(self):
+        """Indicate whether the device is operating in install mode.
+
+        Drivers override this to derive the value from the device's current boot
+        configuration. Used by ``install_os`` to choose between install-mode and
+        legacy upgrade procedures.
+
+        Returns:
+            (bool): True when the device boots from an install-mode bundle
+                (e.g., ``packages.conf`` on IOS-XE), False otherwise.
+        """
+        raise NotImplementedError
+
     def install_os(self, image_name, reboot=True, **vendor_specifics):
         """Install the OS from specified image_name.
 

pyntc/devices/ios_device.py

@@ -3,6 +3,7 @@
 import os
 import re
 import time
+import warnings
 
 from netmiko import ConnectHandler, FileTransfer
 from netmiko.exceptions import ReadTimeout
@@ -319,6 +320,17 @@ def boot_options(self):
         log.debug("Host %s: the boot options are {dict(sys=boot_image)}", self.host)
         return {"sys": boot_image}
 
+    @property
+    def install_mode(self):
+        """Return whether the device is currently booted in install mode.
+
+        Returns:
+            (bool): True when the current boot image equals
+                :data:`INSTALL_MODE_FILE_NAME` (i.e., ``packages.conf``),
+                False otherwise.
+        """
+        return self.boot_options.get("sys") == INSTALL_MODE_FILE_NAME
+
     def checkpoint(self, checkpoint_file):
         """Create checkpoint file.
 
@@ -877,13 +889,28 @@ def file_copy_remote_exists(self, src, dest=None, file_system=None):
         log.debug("Host %s: File %s does not already exist on remote.", self.host, src)
         return False
 
-    def install_os(self, image_name, reboot=True, install_mode=False, read_timeout=2000, **vendor_specifics):
+    def _resolve_install_mode(self, install_mode):
+        """Return the effective install_mode flag, warning if the caller passed it explicitly."""
+        if install_mode is None:
+            return self.install_mode
+        warnings.warn(
+            "The install_mode argument to install_os is deprecated; install mode is now "
+            "derived from the device's boot_options via the install_mode property.",
+            DeprecationWarning,
+        )
+        return install_mode
+
+    def install_os(self, image_name, reboot=True, install_mode=None, read_timeout=2000, **vendor_specifics):
         """Installs the prescribed Network OS, which must be present before issuing this command.
 
         Args:
             image_name (str): Name of the IOS image to boot into
             reboot (bool): Whether to reboot the device after setting the boot options. Defaults to true.
-            install_mode (bool, optional): Uses newer install method on devices. Defaults to False.
+            install_mode (bool, optional): **Deprecated.** Whether to use the newer install-mode
+                upgrade procedure. When omitted (the default), the value is derived from
+                :attr:`install_mode`, which reads the device's current boot configuration.
+                Passing the argument explicitly still works but emits a ``DeprecationWarning``
+                and will be removed in a future release.
             read_timeout (int, optional): Netmiko timeout when waiting for device prompt. Default 2000.
             vendor_specifics (dict, optional): Vendor specific arguments to pass to the install command.
 
@@ -893,14 +920,15 @@ def install_os(self, image_name, reboot=True, install_mode=False, read_timeout=2
         Returns:
             (bool): False if no install is needed, true if the install completes successfully
         """
+        use_install_mode = self._resolve_install_mode(install_mode)
         timeout = vendor_specifics.get("timeout", 3600)
         if not self._image_booted(image_name):
-            if install_mode and not reboot:
+            if use_install_mode and not reboot:
                 raise ValueError(
                     "IOS devices automatically reboot after installation when using install mode but the reboot argument was set to false."
                 )
 
-            if install_mode:
+            if use_install_mode:
                 # Change boot statement to be boot system <flash>:packages.conf
                 self.set_boot_options(INSTALL_MODE_FILE_NAME, **vendor_specifics)
 
@@ -942,7 +970,7 @@ def install_os(self, image_name, reboot=True, install_mode=False, read_timeout=2
             self._wait_for_device_reboot(timeout=timeout)
 
             # Set FastCLI back to originally set when using install mode
-            if install_mode:
+            if use_install_mode:
                 image_name = INSTALL_MODE_FILE_NAME
             # Verify the OS level
             if not self._image_booted(image_name):

tests/unit/test_devices/test_base_device.py

@@ -0,0 +1,15 @@
+"""Tests for the abstract :class:`pyntc.devices.base_device.BaseDevice` contract."""
+
+import pytest
+
+from pyntc.devices.base_device import BaseDevice
+
+
+@pytest.fixture
+def base_device():
+    return BaseDevice(host="host", username="user", password="pass")
+
+
+def test_install_mode_raises_not_implemented(base_device):
+    with pytest.raises(NotImplementedError):
+        _ = base_device.install_mode