Disable nouveau driver

Change-Id: I7f4ba2ba173d40baa9ba140007e7c4bb8055f000

src/charm_utils.py

@@ -95,6 +95,11 @@ def install_nvidia_software_if_needed(stored, config, resources):
         apt_install([nvidia_software_path], fatal=True)
         stored.last_installed_resource_hash = nvidia_software_hash
 
+        # The nouveau driver prevents the nvidia-vgpu-mgr service from
+        # starting, thus it needs to be disabled. Unfortunately this requires
+        # a reboot. The operator will be notified via a blocked unit status.
+        nvidia_utils.disable_nouveau_driver()
+
 
 def check_status(config, services):
     """Determine the unit status to be set.

src/nvidia_utils.py

@@ -16,8 +16,11 @@
 
 
 import logging
+import os
 
 from charmhelpers.core.hookenv import cached
+from charmhelpers.core.kernel import update_initramfs
+from charmhelpers.core.templating import render
 from charmhelpers.fetch import (
     apt_cache,
 )
@@ -45,6 +48,17 @@ def installed_nvidia_software_package_names():
             _installed_nvidia_software_packages()]
 
 
+def disable_nouveau_driver():
+    """Disable the nouveau driver.
+
+    This driver prevents the nvidia-vgpu-mgr service from starting. A reboot is
+    required.
+    """
+    config_file = '/etc/modprobe.d/disable-nouveau.conf'
+    render(os.path.basename(config_file), config_file, {})
+    update_initramfs()
+
+
 @cached
 def has_nvidia_gpu_hardware():
     """Search for NVIDIA GPU hardware.

templates/disable-nouveau.conf

@@ -0,0 +1,2 @@
+blacklist nouveau
+options nouveau modeset=0

unit_tests/test_charm_utils.py

@@ -15,7 +15,7 @@
 import sys
 import unittest
 
-from mock import MagicMock, patch
+from mock import ANY, MagicMock, patch
 
 sys.path.append('src')  # noqa
 
@@ -45,12 +45,14 @@ class TestCharmUtils(unittest.TestCase):
             charm_utils.is_nvidia_software_to_be_installed_notcached({
                 'force-install-nvidia-vgpu': False}))
 
+    @patch('nvidia_utils.update_initramfs')
+    @patch('nvidia_utils.render')
     @patch('charm_utils.apt_install')
     @patch('charm_utils._path_and_hash_nvidia_resource')
     @patch('charm_utils.is_nvidia_software_to_be_installed')
     def test_install_nvidia_software_if_needed(
             self, is_software_to_be_installed_mock, path_and_hash_mock,
-            apt_install_mock):
+            apt_install_mock, render_template_mock, update_initramfs_mock):
         is_software_to_be_installed_mock.return_value = True
         unit_stored_state = MagicMock()
         unit_stored_state.last_installed_resource_hash = 'hash-1'
@@ -75,6 +77,9 @@ class TestCharmUtils(unittest.TestCase):
                                                       None)
         apt_install_mock.assert_called_once_with(['path-to-software'],
                                                  fatal=True)
+        render_template_mock.assert_called_once_with(
+            'disable-nouveau.conf', ANY, ANY)
+        update_initramfs_mock.assert_called_once_with()
 
     @patch('charm_utils.ows_check_services_running')
     @patch('charm_utils.is_nvidia_software_to_be_installed')