Extends save() and restore() functions with ceph block device support

* vmdriver: modify save() and restore() functions
* privcelery: celery daemon for priviliged operations on the temporary dump file
* ceph: ceph block device operations
* util: helper function which returns the privcelery's queuename
* Add init scripts for privcelery

ceph.py

+import rados
+import rbd
+import os
+
+from privcelery import celery
+
+
+class CephConnection:
+
+    def __init__(self, pool_name, ceph_config=None):
+
+        self.pool_name = pool_name
+        self.ceph_config = ceph_config
+        self.cluster = None
+        self.ioctx = None
+
+    def __enter__(self):
+        try:
+            if self.ceph_config is None:
+                self.ceph_config = os.getenv("CEPH_CONFIG",
+                                             "/etc/ceph/ceph.conf")
+            self.cluster = rados.Rados(conffile=self.ceph_config)
+            self.cluster.connect(timeout=2)
+            self.ioctx = self.cluster.open_ioctx(self.pool_name)
+        except rados.InterruptedOrTimeoutError as e:
+            raise Exception(e)
+
+        return self
+
+    def __exit__(self, type, value, traceback):
+
+        self.ioctx.close()
+        self.cluster.shutdown()
+
+
+@celery.task
+def write_to_ceph_block_device(poolname, diskname):
+    diskname = str(diskname)
+    path = "/tmp/" + diskname
+    statinfo = os.stat(path)
+    disk_size = statinfo.st_size
+    with open(path, "rb") as f:
+        with CephConnection(str(poolname)) as conn:
+            rbd_inst = rbd.RBD()
+            try:
+                rbd_inst.create(conn.ioctx, diskname, disk_size)
+            except rbd.ImageExists:
+                rbd_inst.remove(conn.ioctx, diskname)
+                rbd_inst.create(conn.ioctx, diskname, disk_size)
+
+            try:
+                with rbd.Image(conn.ioctx, diskname) as image:
+                    offset = 0
+                    data = f.read(4096)
+                    while data:
+                        offset += image.write(data, offset)
+                        data = f.read(4096)
+            except:
+                rbd_inst.remove(conn.ioctx, diskname)
+                raise
+
+
+@celery.task
+def read_from_ceph_block_device(poolname, diskname):
+    diskname = str(diskname)
+    path = "/tmp/" + diskname
+    try:
+        with open(path, "wb") as f:
+            with CephConnection(str(poolname)) as conn:
+                with rbd.Image(conn.ioctx, diskname) as image:
+                    offset = 0
+                    size = image.size()
+                    while offset < size - 4096:
+                        data = image.read(offset, 4096)
+                        f.write(data)
+                        offset += 4096
+                    data = image.read(offset, size - offset)
+                    f.write(data)
+                rbd_inst = rbd.RBD()
+                rbd_inst.remove(conn.ioctx, diskname)
+    except:
+        with CephConnection(str(poolname)) as conn:
+            rbd_inst = rbd.RBD()
+            rbd_inst.remove(conn.ioctx, diskname)
+        remove_temp_file(path)
+        raise
+
+
+@celery.task
+def remove_temp_file(path):
+    os.unlink(path)

miscellaneous/node.conf

@@ -13,6 +13,11 @@ pre-start script
     do
         start netcelery NAME=$hostname.$inst || :
     done
+
+    for inst in vm.priv
+    do
+        start privcelery NAME=$hostname.$inst || :
+    done
 end script
 
 post-stop script
@@ -24,4 +29,8 @@ post-stop script
     do
         stop netcelery NAME=$inst || :
     done
+    for inst in `initctl list|grep "^privcelery "|awk '{print $2}'|tr -d ')'|tr -d '('`
+    do
+        stop privcelery NAME=$inst || :
+    done
 end script

miscellaneous/node.service

@@ -4,6 +4,7 @@ After=network.target
 BindsTo=netcelery@net.fast.service
 BindsTo=vmcelery@vm.fast.service
 BindsTo=vmcelery@vm.slow.service
+BindsTo=privcelery@vm.priv.service
 BindsTo=agentdriver.service
 
 [Service]

miscellaneous/privcelery.conf

+description	"IK Cloud Django Development Server"
+
+respawn
+respawn limit 30 30
+setuid root
+setgid root
+
+instance $NAME
+
+script
+    cd /home/cloud/vmdriver
+    . /home/cloud/.virtualenvs/vmdriver/local/bin/activate
+    . /home/cloud/.virtualenvs/vmdriver/local/bin/postactivate
+    exec celery -A privcelery worker --loglevel=info -n ${NAME}
+end script

miscellaneous/privcelery@.service

+[Unit]
+Description=privcelery %I
+BindsTo=node.service
+
+[Service]
+User=root
+Group=root
+
+KillSignal=SIGTERM
+TimeoutStopSec=600
+Restart=always
+
+WorkingDirectory=/home/cloud/vmdriver
+
+ExecStart=/bin/bash -c "source /etc/profile; source /home/cloud/.virtualenvs/vmdriver/bin/activate; source /home/cloud/.virtualenvs/vmdriver/bin/postactivate; export C_FORCE_ROOT=\"true\"; exec celery -A privcelery worker --loglevel=info -n $(/bin/hostname -s).%I"

privcelery.py

+""" Celery module for privileged RPC calls. """
+from celery import Celery
+from kombu import Queue, Exchange
+from os import getenv
+
+from argparse import ArgumentParser
+
+parser = ArgumentParser()
+parser.add_argument("-n", "--hostname", dest="hostname",
+                    help="Define the full queue name with"
+                    "with priority", metavar="hostname.queue.priority")
+(args, unknwon_args) = parser.parse_known_args()
+HOSTNAME = vars(args).pop("hostname")
+if HOSTNAME is None:
+    raise Exception("You must define hostname as -n <hostname> or "
+                    "--hostname=<hostname>.\n"
+                    "Hostname format must be hostname.module.priority.")
+
+AMQP_URI = getenv('AMQP_URI')
+
+celery = Celery('privcelery',
+                broker=AMQP_URI,
+                include=['ceph'])
+
+celery.conf.update(
+    CELERY_RESULT_BACKEND='amqp',
+    CELERY_TASK_RESULT_EXPIRES=300,
+    CELERY_QUEUES=(
+        Queue(HOSTNAME, Exchange(
+            'ceph', type='direct'), routing_key="ceph"),
+    )
+)

util.py

+import socket
+import logging
+
+
+logger = logging.getLogger(__name__)
+
+
+def get_priviliged_queue_name():
+    hostname = socket.gethostname()
+    logger.debug("Checking for vmdriver priviliged queue %s.vm.priv",
+                 hostname)
+    queue_name = hostname + '.vm.priv'
+    return queue_name

vmdriver.py

@@ -16,6 +16,12 @@ from vm import VMInstance, VMDisk, CephVMDisk, VMNetwork
 
 from vmcelery import celery, lib_connection, to_bool
 
+from ceph import (write_to_ceph_block_device,
+                  read_from_ceph_block_device,
+                  remove_temp_file)
+from util import get_priviliged_queue_name
+
+
 sys.path.append(os.path.dirname(os.path.basename(__file__)))
 
 vm_xml_dump = None
@@ -324,17 +330,31 @@ def suspend(name):
 @celery.task
 @req_connection
 @wrap_libvirtError
-def save(name, path):
+def save(name, data_store_type, dir, filename):
     """ Stop virtual machine and save its memory to path. """
-
     domain = lookupByName(name)
-    domain.save(path)
+    if data_store_type == "ceph_block":
+        try:
+            path = "/tmp/" + filename
+            domain.save(path)
+            queue_name = get_priviliged_queue_name()
+            write_to_ceph_block_device.apply_async(
+                args=[dir, filename], queue=queue_name).get(timeout=300)
+            remove_temp_file.apply_async(
+                args=[path], queue=queue_name).get(timeout=300)
+        except:
+            remove_temp_file.apply_async(
+                args=[path], queue=queue_name).get(timeout=300)
+            raise
+    else:
+        path = dir + "/" + filename
+        domain.save(path)
 
 
 @celery.task
 @req_connection
 @wrap_libvirtError
-def restore(name, path):
+def restore(name, data_store_type, dir, filename):
     """ Restore a saved virtual machine.
 
     Restores the virtual machine from the memory image
@@ -342,7 +362,18 @@ def restore(name, path):
     Return the domain info dict.
 
     """
-    Connection.get().restore(path)
+    if data_store_type == "ceph_block":
+        path = "/tmp/" + filename
+        queue_name = get_priviliged_queue_name()
+        read_from_ceph_block_device.apply_async(
+            args=[dir, filename], queue=queue_name).get(timeout=300)
+        Connection.get().restore(path)
+        remove_temp_file.apply_async(
+            args=[path], queue=queue_name).get(timeout=300)
+    else:
+        path = dir + "/" + filename
+        Connection.get().restore(path)
+
     return domain_info(name)