Allow configuring the wsgi pool size

Expose the number of greenthreads in wsgi pool to configuration. This
allows to put a limit to the number of resources like memcache
connections used.

DocImpact
Change-Id: I6e53d6e12661ed2f42a6b543891b13eec0c8300c
Enforce metadata string type on key/value pairs

The compute API is currently enforcing quota limits for user metadata
and length restrictions on the dict entries, but is not enforcing that
they are string types. This patch adds the checks for string type on the
keys and values in the metadata dict.

Closes-Bug: #1240319

Change-Id: Ic4aacc342cf37d929871287e6e4917f4f48b63e8
Fix a lazy-load exception in security_group_update()

When security_group_api is nova, the update_security_group api raises http
500 error: group rules fails with lazy load exception. Because the rule
infos of the security group will be return in response body, but the rule
attribute hasn't been preloaded.

Closes-Bug: #1244018
Change-Id: Ie07879ac22e4add90f75968778bf334915e8349c
Fix LibvirtGenericVIFDriver.get_config() for quota

When Nova is used with Neutron and Open vSwitch, network quotas on the
bandwidth are ignored by libvirt: the "<bandwidth>" tag is not generated in
libvirt.xml of the virtual machine. This change fixes this issue but also for
the network types: "bridge", "network" and "direct".

Commands to create the flavor with download limited to 1 MB/sec and create a
virtual machine with this flavor:
---
nova flavor-create --ephemeral=1 victor_test_vif 50 256 1 1
nova flavor-key victor_test_vif set quota:vif_inbound_average=1000
nova boot --flavor=victor_test_vif --image=cirros-0.3.1-x86_64-uec victor_test
---

Commands to upload a file to this virtual machine with SCP to check that the
bandwidth is limited to 1 MB/sec (replace 10.0.0.3 with the IP of the virtual
machine):
---
ip netns
sudo ip netns exec qrouter-128db593-a0db-40c3-84c7-e6383d40c75f bash

dd if=/dev/urandom of=random10MB bs=1024 count=10240
scp random10M cirros@10.0.3:
---

Change-Id: I0f0111fc79fe90900e38df022034b208f1129088
Closes-Bug: #1254664
DB migration 209: Clean up child rows as well

Fixes bug 1252891

In order to add missing foreign key constraints, rows that reference a
nonexistant key need to be purged. Unfortunately, DB migration 209 does
not clean up any rows in child tables that themselves have a foreign key
constraint on the tables with the missing foreign keys. This can result
in an integrity violation causing the migration to fail.

When purging the rows, make sure to purge rows in any child tables first.

Change-Id: I25bd899383c72cb0670819b030759630ac89acaa
Update Instance from database after destroy

In cases where Nova falls back to simply locally deleting an
instance, the Instance object was not updated with the deleted_at
generated by the database implementation. Due to this, the
notification emitted to signify that the delete finished was
getting emitted without a deleted_at value.

This change uses the result from the instance_destroy call to
update the Instance object with the latest state from the database.
Thus, the compute.instance.delete.end notification is emitted
with the proper deleted_at value.

Closes-Bug: #1250206
Change-Id: I55ed37cf89dd6eb8ea901c6f813191a0ce1058e8
Add shutdown option to cleanup running periodic

Add a 'shutdown' option to the periodic task that cleans up instances
which are both deleted *and* running.

The option powers down instances and marks them as non-bootable.  This
is a flag for system administrators who would like to reclaim the
resources consumed by each instance, but leave the records around for
later examination/debugging.

DocImpact
Implements: blueprint cleanup-running-deleted-shutdown

Change-Id: Id95845eb995b62ed8858fe61c6fdb34045721674
Add extra_resources field to compute_nodes table

The compute_nodes table has informtion about allocation and
availability of a predefined set of resources (e.g. memory,
disk, vcpu). The extra_resources field will contain a json
string of arbirtrary information describing an extensible set
of resources that will be tracked by resource tracker plug-ins.

This differs from other fields containing json strings that have
been added recently, including pci_stats and metrics. In particular,
pci_stats is used for information about pci devices, whereas metrics
contains continuously monitored usage data and is updated at different
times to extra_resources and according to a different trigger.
Accordingly, it makes sense to seperate these into different fields.

This is part of: blueprint extensible-resource-tracking

Change-Id: I75e339c2a2827875078c937e57c37e85d3ad1852
Setup destination disk from virt_disk_size

When running live-migration --block-migrate on a qcow2 backed
VM without cow image, the destination qcow2 file should be created
with the virtual disk size. For raw images, the virt_disk_size
is set to disk_size to ensure that virt_disk_size is always the
size of the disk that should be re-created.

Update unit tests to be more strict and check for sizes to be correct.

Closes-Bug: #1257355

Change-Id: Ie3be46024f06b9f59af92f5e3918a1958386d4f1
Make it possible to override test timeout value

Currently, we are setting the test timeout value globally
in .testr.conf. It could be useful to be able to override
it per test case (e.g. for migrations tests which usually
take much longer to run than any other tests).

Related-Bug: #1216851

Change-Id: Icee09609f76f4439f6d981641be521d8d695a77e
Get test_openAuth_can_refuse_None_uri to cleanup after itself

test_openAuth_can_refuse_None_uri sets the global
libvirt.allow_default_uri_connection to False but it leaves
it in this state which could cause test_tpool_execute_calls_libvirt
to fail if it ran immediately afterwards. This patch adds a cleanup
so _reset is called at the end of the test and not just if
another test in the same class is run after it.

Change-Id: I9762fcb81b2318beeb056c67bd9172056e1449ab
Closes-Bug: 1258553
Give migrations tests more time to run

Migrations tests usually take longer to run that most other
tests. Increase the time out value just for migrations tests,
so that we don't hit various time out errors running unit tests
when CI test nodes slow down a bit.

Closes-Bug: #1216851

Change-Id: I48d7c125397cd282d52eb8e1a1ccb699188d8f14
libvirt: Custom disk_bus setting is being lost on hard_reboot

Currently, a non-default disk_bus setting of and image will not be used,
when powering on an instance (or _hard_reboot).

hard_reboot() should use image_meta, if it exist, when constructing
the disk_info

Closes-Bug: #1255449

Change-Id: I477f69c47515ad22165421b4d23ac865c7869873
Log exception in _heal_instance_info_cache

Previously, if errors occurred in _heal_instance_info_cache() they would
go unnoticed as their log level was debug and the stace trace was not
displayed. This patch changes that so the exception is logged so periodic
failures here can be more easily detected and fixed.

Change-Id: I15bb3e7e29462e930f6159be9f4bbf4980b1270c
Closes-bug: #1257940
Move calls to os.path.exists() in libvirt imagebackend

The checks for the path existence were removed from the base Image class
to avoid redundant checks (some of implementations also perform them and
behave differently depending on the results). Also special handling for
some backends were removed from the base Image class.

Change-Id: Ie6cdf0d6d9801f84fae7a58c1034547611712323
Closes-Bug: #1152748
VMware: fix bug when more than one datacenter exists

In the case that there was more than one datacenter defined on the VC,
then spawning an instance would result in an exception. The reason for this
was that the nova compute would not set the correct datacenter for the
selected datastore.

The fix also takes care of the correct folder selection. This too was a
result of not selecting the correct folder for the data center.

The 'fake' configuration was updated to contain an additional data
center with its on datastore.

Closes-Bug: #1180044
Closes-Bug: #1214850

Co-authored-by: Shawn Harsock <hartsocks@vmware.com>

Change-Id: Ib61811fffcbc80385efc3166c9e366fdaa6432bd
Rename instance_type to flavor in test_utils and nova.tests.utils

Renames occurrences of 'instance_type' to 'flavor' in
nova.tests.test_utils and nova.tests.utils along with any impacted tests
using the changed parts.

Part of blueprint flavor-instance-type-dedup

Change-Id: Ie816356c176c2be61b4a346a4d47d8f3461ae84a
XenAPI: Speedup host_ref cannot change - get it once

The host we run on is fixed - getting this each time from XAPI
is expensive

Change-Id: Ifee9a778f3ed855ef52b001de3fc2ebbd0b972cf
Compact pre-Icehouse database migrations <= 170.

Compacts the pre-Icehouse database migrations <= 170 into a
single migration (170_havana.py).

Pre-Icehouse users will now need to upgrade to Havana before
running any Icehouse migrations.

Tested on MySQL and PostgreSQL schemas on Fedora 19 to ensure the
new compacted migration generates an identical schema to the
previous migrate scripts in Havana.

Specific changes include:

1) removed 161_fix_system_metadata_none_strings.py. Nothing to
do here since this was a data conversion (no schema changes)

2) Removed some placeholder migrations for the Grizzly stable
branch.

Change-Id: I94a080ca122af009304975044f33c5e5192834ab
Implements: blueprint compact-havana-db-migrations
Normalize the weights instead of using raw values

The weight system is being used by the scheduler and the cells code.
Currently this system is using the raw values instead of normalizing them.
This makes difficult to properly use multipliers for establishing the
relative importance between two wheighers (one big magnitude could
shade a smaller one). This change introduces weight normalization so
that:

- From an operator point of view we can prioritize the weighers that
  we are applying. The only way to do this is being sure that all the
  weighers will give a value in a known range, so that it is
  not needed to artificially use a huge multiplier to prioritize a
  weigher.

- From a weigher developer point of view, somebody willing to implement
  one has to care about 1) returning a list of values, 2) setting the
  minimum and maximum values where the weights can range, if they are
  needed and they are significant for the weighing. For a weigher
  developer there are two use cases:

    Case 1: Use of a percentage instead of absolute values (for example, %
    of free RAM). If we compare two nodes focusing on the percentage of free
    ram, the maximum value for the weigher is 100. If we have two nodes one
    with 2048 total/1024 free, and the second one 1024 total/512 free they
    will get both the same weight, since they have the same % of free RAM
    (that is, the 50%).

    Case 2: Use of absolute values. In this case, the maximum of the weigher
    will be the maximum of the values in the list (in the case above, 1024)
    or the maximum value that the magnitude could take (in the case above,
    2048). How this maximum is set, is a decision of the developer. He may
    let the operator choose the behaviour of the weigher though.

- From the point of view of the scheduler we ensure that it is using
  normalized values, and not leveraging the normalization mechanism to the
  weighers.

Changes introduced this commit:

1) it introduces weight normalization so that we can apply multipliers
   easily. All the weights for an object will be normalized between 0.0 and
   1.0 before being sumed up, so that the final weight for a host will be:

    weight = w1_multiplier * norm(w1) + w2_multiplier * norm(w2) + ...

2) weights.BaseWeigher has been changed into an ABC so that we enforce
   that all weighers have the expected methods.

3) weights.BaseWeigher.weigh_objects() does no longer sum up the
   computer weighs to the object, but it rather returns a list that will be
   then normalized and added to the existing weight by BaseWeightHandler

4) Adapt the existing weighers to the above changes. Namely
    - New 'offset_weight_multiplier' for the cell weigher
      nova.cells.weights.weight_offset.WeightOffsetWeigher
    - Changed the name of the existing multiplier methods.

5) unittests for all of the introduced changes.

Implements blueprint normalize-scheduler-weights

DocImpact: Now weights for an object are normalized before suming them
up. This means that each weigher will take a maximum value of 1. This
may have an impact for operators that are using more than one weigher
(currently there is only one weigher: RAMWeiger) and for operators using
cells (where we have several weighers). It is needed to review then the
multipliers used and adjust them properly in case they have been
modified.

Docimpact: There is a new configuration option 'offset_weight_multiplier'
in nova.cells.weights.weight_offset.WeightOffsetWeigher

Change-Id: I81bf90898d3cb81541f4390596823cc00106eb20