Make RAPI CreateInstance() arguments configurable

Make RAPI CreateInstance() arguments deployment-specific.
Add the GANETI_CREATEINSTANCE_KWARGS setting, which allows the administrator
to set arbitrary arguments to RAPI CreateInstance().

Also add initial version of README.Upgrade, detailing
upgrades of Synnefo deployments.

Fixes #835

README.Upgrade

+README.Upgrade
+===============
+
+This file documents the upgrade to newer versions of the Synnefo software.
+
+v0.5.1 -> v0.5.2
+NEW SETTINGS
+    * 10-backend.py:GANETI_CREATEINSTANCE_KWARGS
+
+REMOVE SETTINGS
+    * 10-backend.conf/GANETI_OS_PROVIDER
+    * 20-apo.conf/GANETI_DISK_TEMPLATE
+
+BACKEND CHANGES
+    * Need to patch Ganeti, file:
+      lib/python2.6/site-packages/ganeti/rapi/rlib2.py
+      to honor the wait_for_sync flag, see Synnefo #835.
+      Patch provided under contrib/patches/ganeti-rlib2.py-v0.5.2

README.deploy

-README.deploy -- Instructions for a basic deployment of Synnefo v0.5.1
+README.deploy -- Instructions for a basic Synnefo deployment
 
 This document describes the basic steps to obtain a basic, working Synnefo
 deployment. It begins by examining the different node roles, then moves to the
 installation and setup of distinct software components.
 
-It is current as of Synnefo v0.5.1.
+It is current as of Synnefo v0.5.2.
 
 
 Node types
@@ -418,7 +418,7 @@ Synnefo deployment.
 
     Download and install gnt-instance-image in all Ganeti nodes from its own
     repository, at https://code.grnet.gr/git/gnt-instance-image. It's
-    recommended to use the win-support branch (known good commit for 0.5.1:
+    recommended to use the win-support branch (known good commit for 0.5.2:
     8afaedb329c981282aed1a6c3daf62e43532f00d).
 
     After installing gnt-instance-image do the following:

contrib/patches/ganeti-rlib2.py-v0.5.2

+--- rlib2.py    2011-07-17 20:45:56.000000000 +0300
++++ rlib2.py.20110717   2011-07-17 20:45:51.000000000 +0300
+@@ -785,7 +785,7 @@
+     src_node=baserlib.CheckParameter(data, "src_node", default=None),
+     src_path=baserlib.CheckParameter(data, "src_path", default=None),
+     start=baserlib.CheckParameter(data, "start", default=True),
+-    wait_for_sync=baserlib.CheckParameter(data, "wait_for_sync", default=True),
++    wait_for_sync=True,
+     ip_check=baserlib.CheckParameter(data, "ip_check", default=True),
+     name_check=baserlib.CheckParameter(data, "name_check", default=True),
+     file_storage_dir=baserlib.CheckParameter(data, "file_storage_dir",

logic/backend.py

@@ -183,26 +183,36 @@ def create_instance(vm, flavor, image, password):
     else:
         sz = flavor.disk * 1024
 
-    return rapi.CreateInstance(
-        mode='create',
-        name=vm.backend_id,
-        disk_template=settings.GANETI_DISK_TEMPLATE,
-        disks=[{"size": sz}],     #FIXME: Always ask for a 4GB disk for now
-        nics=[nic],
-        os=settings.GANETI_OS_PROVIDER,
-        ip_check=False,
-        name_check=False,
-        # Do not specific a node explicitly, have
-        # Ganeti use an iallocator instead
-        #
-        # pnode=rapi.GetNodes()[0],
-        dry_run=settings.TEST,
-        beparams=dict(auto_balance=True, vcpus=flavor.cpu, memory=flavor.ram),
-        osparams=dict(img_id=image.backend_id, img_passwd=password,
-                      img_format=image.format),
-        # Be explicit about setting serial_console = False for Synnefo-based
-        # instances regardless of the cluster-wide setting, see #785
-        hvparams=dict(serial_console=False))
+    # Handle arguments to CreateInstance() as a dictionary,
+    # initialize it based on a deployment-specific value.
+    # This enables the administrator to override deployment-specific
+    # arguments, such as the disk templatei to use, name of os provider
+    # and hypervisor-specific parameters at will (see Synnefo #785, #835).
+    #
+    kw = settings.GANETI_CREATEINSTANCE_KWARGS
+    kw['mode'] = 'create'
+    kw['name'] = vm.backend_id
+    # Defined in settings.GANETI_CREATE_INSTANCE_KWARGS
+    # kw['disk_template'] = settings.GANETI_DISK_TEMPLATE
+    kw['disks'] = [{"size": sz}]
+    kw['nics'] = [nic]
+    # Defined in settings.GANETI_CREATE_INSTANCE_KWARGS
+    # kw['os'] = settings.GANETI_OS_PROVIDER
+    kw['ip_check'] = False
+    kw['name_check'] = False
+    # Do not specific a node explicitly, have
+    # Ganeti use an iallocator instead
+    #
+    # kw['pnode']=rapi.GetNodes()[0]
+    kw['dry_run'] = settings.TEST
+    kw['beparams'] = dict(auto_balance=True, vcpus=flavor.cpu,
+                          memory=flavor.ram)
+    kw['osparams'] = dict(img_id=image.backend_id, img_passwd=password,
+                         img_format=image.format)
+    # Defined in settings.GANETI_CREATE_INSTANCE_KWARGS
+    # kw['hvparams'] = dict(serial_console=False)
+
+    return rapi.CreateInstance(**kw)
 
 
 def delete_instance(vm):

settings.d/10-backend.conf

@@ -13,4 +13,24 @@ GANETI_CLUSTER_INFO = (GANETI_MASTER_IP, 5080, "synnefo", "ocean!")
 # The dash must always appear in the name!
 BACKEND_PREFIX_ID = "snf-"
 
-GANETI_OS_PROVIDER = "image+default"
+# The following dictionary defines deployment-specific
+# arguments to the RAPI CreateInstance call.
+# At a minimum it should contain the
+# 'disk_template', 'os_provider', and 'hvparams' keys.
+#
+# More specifically:
+# a) disk_template:
+#    The disk template to use when creating the instance.
+#    Suggested values: 'plain', or 'drbd'.
+# b) os:
+#    The OS provider to use (customized Ganeti Instance Image)
+# c) hvparams:
+#    Hypervisor-specific parameters (serial_console = False, see #785)
+# d) If using the DRBD disk_template, you may want to include
+#    wait_for_sync = False (see #835).
+#
+GANETI_CREATEINSTANCE_KWARGS = {
+    'disk_template': 'drbd',
+    'os': 'image+default',
+    'hvparams': {'serial_console': False},
+    'wait_for_sync': False}

settings.d/20-api.conf

@@ -47,10 +47,6 @@ APPEND_SLASH = False
 #
 IGNORE_FLAVOR_DISK_SIZES = False
 
-# Use the following disk template when creating an instance
-# on the Ganeti backend. Suggested values: 'plain', or 'drbd'.
-GANETI_DISK_TEMPLATE = 'plain'
-
 # Quota
 #
 # Maximum number of VMs a user is allowed to have