Enable support for auto-converge and post-copy

Implement missing configuration options and context to support
configuration of:

  live_migration_permit_auto_converge
  live_migration_permit_post_copy

in nova.conf. The configuration parameters are only added to the
nova.conf template when live-migration is actually enabled, since they
have no purpose without live-migration enabled. The options are added to
version Newton and upwards as that is the Nova version since they were
first supported.

Change-Id: I1bb3cee4ac532d0867b4297c742707668566a527
Closes-Bug: #1799916
(cherry picked from commit 1fa2a8023c)

config.yaml

@@ -108,6 +108,18 @@ options:
     description: |
       TCP authentication scheme for libvirt live migration. Available options
       include ssh.
+  live-migration-permit-post-copy:
+    type: boolean
+    default: False
+    description: |
+      If live-migration is enabled, this option allows Nova to switch an on-
+      going live migration to post-copy mode.
+  live-migration-permit-auto-converge:
+    type: boolean
+    default: False
+    description: |
+      If live-migration is enabled, this option allows Nova to throttle down
+      CPU when an on-going live migration is slow.
   authorized-keys-path:
     type: string
     default: '{homedir}/.ssh/authorized_keys'

hooks/nova_compute_context.py

@@ -198,6 +198,12 @@ class NovaComputeLibvirtContext(context.OSContextGenerator):
             # nova.conf
             ctxt['live_migration_uri'] = 'qemu+ssh://%s/system'
 
+        if config('enable-live-migration'):
+            ctxt['live_migration_permit_post_copy'] = \
+                config('live-migration-permit-post-copy')
+            ctxt['live_migration_permit_auto_converge'] = \
+                config('live-migration-permit-auto-converge')
+
         if config('instances-path') is not None:
             ctxt['instances_path'] = config('instances-path')
 

templates/newton/nova.conf

@@ -199,6 +199,12 @@ rbd_secret_uuid = {{ rbd_secret_uuid }}
 {% if live_migration_uri -%}
 live_migration_uri = {{ live_migration_uri }}
 {% endif -%}
+{% if live_migration_permit_post_copy -%}
+live_migration_permit_post_copy = {{ live_migration_permit_post_copy }}
+{% endif -%}
+{% if live_migration_permit_auto_converge -%}
+live_migration_permit_auto_converge = {{ live_migration_permit_auto_converge }}
+{% endif -%}
 {% if disk_cachemodes -%}
 disk_cachemodes = {{ disk_cachemodes }}
 {% endif %}

templates/ocata/nova.conf

@@ -203,6 +203,12 @@ rbd_secret_uuid = {{ rbd_secret_uuid }}
 {% if live_migration_uri -%}
 live_migration_uri = {{ live_migration_uri }}
 {% endif -%}
+{% if live_migration_permit_post_copy -%}
+live_migration_permit_post_copy = {{ live_migration_permit_post_copy }}
+{% endif -%}
+{% if live_migration_permit_auto_converge -%}
+live_migration_permit_auto_converge = {{ live_migration_permit_auto_converge }}
+{% endif -%}
 {% if disk_cachemodes -%}
 disk_cachemodes = {{ disk_cachemodes }}
 {% endif %}

templates/pike/nova.conf

@@ -211,6 +211,12 @@ rbd_secret_uuid = {{ rbd_secret_uuid }}
 {% if live_migration_uri -%}
 live_migration_uri = {{ live_migration_uri }}
 {% endif -%}
+{% if live_migration_permit_post_copy -%}
+live_migration_permit_post_copy = {{ live_migration_permit_post_copy }}
+{% endif -%}
+{% if live_migration_permit_auto_converge -%}
+live_migration_permit_auto_converge = {{ live_migration_permit_auto_converge }}
+{% endif -%}
 {% if disk_cachemodes -%}
 disk_cachemodes = {{ disk_cachemodes }}
 {% endif %}

unit_tests/test_nova_compute_contexts.py

@@ -250,6 +250,50 @@ class NovaComputeContextTests(CharmTestCase):
              'listen_tls': 0,
              'host_uuid': self.host_uuid,
              'live_migration_uri': 'qemu+ssh://%s/system',
+             'live_migration_permit_auto_converge': False,
+             'live_migration_permit_post_copy': False,
+             'force_raw_images': True,
+             'reserved_host_memory': 512}, libvirt())
+
+    def test_libvirt_bin_context_migration_tcp_listen_with_auto_converge(self):
+        self.kv.return_value = FakeUnitdata(**{'host_uuid': self.host_uuid})
+        self.lsb_release.return_value = {'DISTRIB_CODENAME': 'lucid'}
+        self.test_config.set('enable-live-migration', True)
+        self.test_config.set('live-migration-permit-auto-converge', True)
+        libvirt = context.NovaComputeLibvirtContext()
+
+        self.assertEqual(
+            {'libvirtd_opts': '-d -l',
+             'libvirt_user': 'libvirtd',
+             'arch': platform.machine(),
+             'ksm': 'AUTO',
+             'kvm_hugepages': 0,
+             'listen_tls': 0,
+             'host_uuid': self.host_uuid,
+             'live_migration_uri': 'qemu+ssh://%s/system',
+             'live_migration_permit_auto_converge': True,
+             'live_migration_permit_post_copy': False,
+             'force_raw_images': True,
+             'reserved_host_memory': 512}, libvirt())
+
+    def test_libvirt_bin_context_migration_tcp_listen_with_post_copy(self):
+        self.kv.return_value = FakeUnitdata(**{'host_uuid': self.host_uuid})
+        self.lsb_release.return_value = {'DISTRIB_CODENAME': 'lucid'}
+        self.test_config.set('enable-live-migration', True)
+        self.test_config.set('live-migration-permit-post-copy', True)
+        libvirt = context.NovaComputeLibvirtContext()
+
+        self.assertEqual(
+            {'libvirtd_opts': '-d -l',
+             'libvirt_user': 'libvirtd',
+             'arch': platform.machine(),
+             'ksm': 'AUTO',
+             'kvm_hugepages': 0,
+             'listen_tls': 0,
+             'host_uuid': self.host_uuid,
+             'live_migration_uri': 'qemu+ssh://%s/system',
+             'live_migration_permit_auto_converge': False,
+             'live_migration_permit_post_copy': True,
              'force_raw_images': True,
              'reserved_host_memory': 512}, libvirt())