add run_image command

teeth_agent/errors.py

@@ -93,3 +93,14 @@ class ImageWriteError(errors.RESTError):
         super(ImageWriteError, self).__init__()
         self.details = 'Writing image to device {} failed with exit code {}.'
         self.details = self.details.format(device, exit_code)
+
+
+class SystemRebootError(errors.RESTError):
+    """Error raised when a system cannot reboot."""
+
+    message = 'Error rebooting system.'
+
+    def __init__(self, exit_code):
+        super(SystemRebootError, self).__init__()
+        self.details = 'Reboot script failed with exit code {}.'
+        self.details = self.details.format(exit_code)

teeth_agent/shell/reboot.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+#
+# This script reboots by echoing into /proc/sysrq_trigger.
+
+set -e
+
+echo "s" > /proc/sysrq-trigger
+echo "b" > /proc/sysrq-trigger

teeth_agent/standby.py

@@ -40,11 +40,15 @@ def _write_local_config_drive(location, data):
         f.write(json_data)
 
 
+def _path_to_script(script):
+    cwd = os.path.dirname(os.path.realpath(__file__))
+    return os.path.join(cwd, script)
+
+
 def _write_image(image_info, configdrive_dir, device):
     image = _image_location(image_info)
 
-    cwd = os.path.dirname(os.path.realpath(__file__))
-    script = os.path.join(cwd, 'shell/makefs.sh')
+    script = _path_to_script('shell/makefs.sh')
     command = ['/bin/bash', script, configdrive_dir, image, device]
 
     exit_code = subprocess.call(command)
@@ -95,6 +99,15 @@ def _verify_image(image_info, image_location):
     return False
 
 
+def _run_image():
+    script = _path_to_script('shell/reboot.sh')
+    command = ['/bin/bash', script]
+    # this should never return if successful
+    exit_code = subprocess.call(command)
+    if exit_code != 0:
+        raise errors.SystemRebootError(exit_code)
+
+
 class CacheImagesCommand(base.AsyncCommandResult):
     def execute(self):
         # TODO(russellhaering): Actually cache images
@@ -116,8 +129,7 @@ class PrepareImageCommand(base.AsyncCommandResult):
 
 class RunImageCommand(base.AsyncCommandResult):
     def execute(self):
-        # TODO(jimrollenhagen): Actually run image, reboot/kexec/whatever
-        pass
+        _run_image()
 
 
 class StandbyAgent(base.BaseTeethAgent):

teeth_agent/tests/standby_agent.py

@@ -16,7 +16,6 @@ limitations under the License.
 
 import json
 import mock
-import os
 import unittest
 
 from teeth_agent import errors
@@ -133,8 +132,7 @@ class TestBaseTeethAgent(unittest.TestCase):
         configdrive = 'configdrive'
         device = '/dev/sda'
         location = standby._image_location(image_info)
-        standby_dir = os.path.dirname(os.path.realpath(standby.__file__))
-        script = os.path.join(standby_dir, 'shell/makefs.sh')
+        script = standby._path_to_script('shell/makefs.sh')
         command = ['/bin/bash', script, configdrive, location, device]
         call_mock.return_value = 0
 
@@ -226,3 +224,20 @@ class TestBaseTeethAgent(unittest.TestCase):
         verified = standby._verify_image(image_info, image_location)
         self.assertFalse(verified)
         self.assertEqual(md5_mock.call_count, 1)
+
+    @mock.patch('subprocess.call', autospec=True)
+    def test_run_image(self, call_mock):
+        script = standby._path_to_script('shell/reboot.sh')
+        command = ['/bin/bash', script]
+        call_mock.return_value = 0
+
+        standby._run_image()
+        call_mock.assert_called_once_with(command)
+
+        call_mock.reset_mock()
+        call_mock.return_value = 1
+
+        self.assertRaises(errors.SystemRebootError,
+                          standby._run_image)
+
+        call_mock.assert_called_once_with(command)