compute: Add support for triggering crash dumps

Add support for compute API microversion 2.17, which allowed admins to
trigger a crash dump in a running server.

Change-Id: Ie0409f11f2a2b03044dfb504748e0177cae0d6b0
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

openstack/compute/v2/_proxy.py

@@ -1011,6 +1011,23 @@ class Proxy(proxy.Proxy):
         server = self._get_resource(_server.Server, server)
         server.unshelve(self)
 
+    def trigger_server_crash_dump(self, server):
+        """Trigger a crash dump in a server.
+
+        When a server starts behaving oddly at a fundamental level, it maybe be
+        useful to get a kernel level crash dump to debug further. The crash
+        dump action forces a crash dump followed by a system reboot of the
+        server. Once the server comes back online, you can find a Kernel Crash
+        Dump file in a certain location of the filesystem. For example, for
+        Ubuntu you can find it in the /var/crash directory.
+
+        :param server: Either the ID of a server or a
+            :class:`~openstack.compute.v2.server.Server` instance.
+        :returns: None
+        """
+        server = self._get_resource(_server.Server, server)
+        server.trigger_crash_dump(self)
+
     # ========== Server security groups ==========
 
     def fetch_server_security_groups(self, server):

openstack/compute/v2/server.py

@@ -488,6 +488,10 @@ class Server(resource.Resource, metadata.MetadataMixin, tag.TagMixin):
         body = {"migrate": None}
         self._action(session, body)
 
+    def trigger_crash_dump(self, session):
+        body = {"trigger_crash_dump": None}
+        self._action(session, body)
+
     def get_console_output(self, session, length=None):
         body = {"os-getConsoleOutput": {}}
         if length is not None:
@@ -495,6 +499,14 @@ class Server(resource.Resource, metadata.MetadataMixin, tag.TagMixin):
         resp = self._action(session, body)
         return resp.json()
 
+    def get_console_url(self, session, console_type):
+        action = CONSOLE_TYPE_ACTION_MAPPING.get(console_type)
+        if not action:
+            raise ValueError("Unsupported console type %s" % console_type)
+        body = {action: {'type': console_type}}
+        resp = self._action(session, body)
+        return resp.json().get('console')
+
     def live_migrate(self, session, host, force, block_migration,
                      disk_over_commit=False):
         if utils.supports_microversion(session, '2.30'):
@@ -514,14 +526,6 @@ class Server(resource.Resource, metadata.MetadataMixin, tag.TagMixin):
                 block_migration=block_migration,
                 disk_over_commit=disk_over_commit)
 
-    def get_console_url(self, session, console_type):
-        action = CONSOLE_TYPE_ACTION_MAPPING.get(console_type)
-        if not action:
-            raise ValueError("Unsupported console type %s" % console_type)
-        body = {action: {'type': console_type}}
-        resp = self._action(session, body)
-        return resp.json().get('console')
-
     def _live_migrate_30(self, session, host, force, block_migration):
         microversion = '2.30'
         body = {'host': None}

openstack/tests/unit/compute/v2/test_proxy.py

@@ -921,6 +921,13 @@ class TestCompute(TestComputeProxy):
             method_args=["value"],
             expected_args=[self.proxy])
 
+    def test_server_trigger_dump(self):
+        self._verify(
+            "openstack.compute.v2.server.Server.trigger_crash_dump",
+            self.proxy.trigger_server_crash_dump,
+            method_args=["value"],
+            expected_args=[self.proxy])
+
     def test_get_server_output(self):
         self._verify(
             "openstack.compute.v2.server.Server.get_console_output",

openstack/tests/unit/compute/v2/test_server.py

@@ -820,6 +820,18 @@ class TestServer(base.TestCase):
         self.sess.post.assert_called_with(
             url, json=body, headers=headers, microversion=None)
 
+    def test_trigger_crash_dump(self):
+        sot = server.Server(**EXAMPLE)
+
+        res = sot.trigger_crash_dump(self.sess)
+
+        self.assertIsNone(res)
+        url = 'servers/IDENTIFIER/action'
+        body = {'trigger_crash_dump': None}
+        headers = {'Accept': ''}
+        self.sess.post.assert_called_with(
+            url, json=body, headers=headers, microversion=None)
+
     def test_get_console_output(self):
         sot = server.Server(**EXAMPLE)
 

releasenotes/notes/compute-microversion-2-17-b05cb87580b8d56a.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Add support for Compute API microversion 2.17, which allows admins to
+    trigger a crash dump for a server. This can be useful for debugging
+    misbehaving guests.