Add attaching and detaching cinder volumes

Partially implement blueprint attach-cinder-volume

Change-Id: I9e60122868e1873948a9e1db87d2181bc06e2a8f

savanna/service/instances.py

@@ -18,6 +18,7 @@ from savanna.db import models as m
 from savanna.openstack.common import excutils
 from savanna.openstack.common import log as logging
 from savanna.service import networks
+from savanna.service import volumes
 from savanna.utils import crypto
 from savanna.utils.openstack import nova
 
@@ -36,6 +37,9 @@ def create_cluster(cluster):
         context.model_save(cluster)
         _await_instances(cluster)
 
+        # attach volumes
+        volumes.attach(cluster)
+
         # prepare all instances
         cluster.status = 'Preparing'
         context.model_save(cluster)
@@ -221,6 +225,7 @@ def _rollback_cluster_creation(cluster, ex):
     # update cluster status description
     session = context.ctx().session
     _shutdown_instances(cluster, True)
+    volumes.detach(cluster)
     alive_instances = set([srv.id for srv in nova.client().servers.list()])
 
     for node_group in cluster.node_groups:
@@ -261,4 +266,5 @@ def _shutdown_instance(instance):
 
 def shutdown_cluster(cluster):
     """Shutdown specified cluster and all related resources."""
+    volumes.detach(cluster)
     _shutdown_instances(cluster)

savanna/service/volumes.py

@@ -0,0 +1,134 @@
+# Copyright (c) 2013 Mirantis Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import re
+import six
+
+from savanna import context
+from savanna.openstack.common import log as logging
+from savanna.utils.openstack import cinder
+from savanna.utils.openstack import nova
+
+LOG = logging.getLogger(__name__)
+
+
+def attach(cluster):
+    for node_group in cluster.node_groups:
+        for instance in node_group.instances:
+            _attach_volumes_to_node(node_group, instance)
+
+
+def _await_attach_volume(instance, device_path):
+    timeout = 10
+    for _ in six.moves.xrange(timeout):
+        device_paths = _get_device_paths(instance)
+        if device_path in device_paths:
+            return
+        else:
+            context.sleep(1)
+
+    raise RuntimeError("Error attach volume to instance %s" %
+                       instance.instance_name)
+
+
+def _attach_volumes_to_node(node_group, instance, volume_type=None):
+    count = node_group.volumes_per_node
+    size = node_group.volumes_size
+    for idx in range(1, count + 1):
+        device_path = _get_free_device_path(instance)
+        display_name = "volume_" + instance.instance_name + "_" + str(idx)
+
+        _create_attach_volume(instance, size, device_path, display_name,
+                              volume_type)
+        _await_attach_volume(instance, device_path)
+        LOG.debug("Attach volume to instance %s, type %s" %
+                  (instance.instance_id, volume_type))
+        mount_point = node_group.storage_paths[idx - 1]
+        _mount_volume(instance, device_path, mount_point)
+        LOG.debug("Mount volume to instance %s" % instance.instance_id)
+
+
+def _create_attach_volume(instance, size, device_path, display_name=None,
+                          volume_type=None):
+    volume = cinder.client().volumes.create(size=size,
+                                            display_name=display_name,
+                                            volume_type=volume_type)
+    instance.volumes.append(volume.id)
+
+    while volume.status != 'available':
+        volume = cinder.get_volume(volume.id)
+        if volume.status == 'error':
+            raise RuntimeError("Volume %s has error status" % volume.id)
+
+        context.sleep(1)
+
+    nova.client().volumes.create_server_volume(instance.instance_id,
+                                               volume.id, device_path)
+
+
+def _get_device_paths(instance):
+    code, part_info = instance.remote.execute_command('cat /proc/partitions')
+    if code:
+        raise RuntimeError("Unable get device paths info")
+
+    out = part_info.split('\n')[1:]
+    device_paths = []
+    for line in out:
+        spl = line.split()
+        if len(spl) > 3:
+            dev = spl[3]
+            if not re.search('\d$', dev):
+                device_paths.append('/dev/' + dev)
+
+    return device_paths
+
+
+def _get_free_device_path(instance):
+    device_paths = _get_device_paths(instance)
+    for idx in range(0, 26):
+        device_path = '/dev/vd' + chr(ord('a') + idx)
+        if device_path not in device_paths:
+            return device_path
+
+    raise RuntimeError("Unable get free device path")
+
+
+def _mount_volume(instance, device_path, mount_point):
+    codes = []
+    with instance.remote as remote:
+        code, _ = remote.execute_command('sudo mkdir -p %s' % mount_point)
+        codes.append(code)
+        code, _ = remote.execute_command('sudo mkfs.ext4 %s' % device_path)
+        codes.append(code)
+        code, _ = remote.execute_command('sudo mount %s %s' % (device_path,
+                                                               mount_point))
+        codes.append(code)
+
+    if any(codes):
+        raise RuntimeError("Error mounting volume to instance %s" %
+                           instance.instance_id)
+
+
+def detach(cluster):
+    for node_group in cluster.node_groups:
+        for instance in node_group.instances:
+            for volume_id in instance.volumes:
+                volume = cinder.get_volume(volume_id)
+                try:
+                    volume.detach()
+                    volume.delete()
+                except Exception:
+                    LOG.error("Can't detach volume %s" % volume.id)
+                    raise