This patch adds initial support for deploying multiple Nova cells.

Splitting a nova-cell role out from the Nova role allows a more granular
approach to deploying and configuring Nova services.

A new enable_cells flag has been added that enables the support of
multiple cells via the introduction of a super conductor in addition to
cell-specific conductors. When this flag is not set (the default), nova
is configured in the same manner as before - with a single conductor.

The nova role now deploys the global services:

* nova-api
* nova-scheduler
* nova-super-conductor (if enable_cells is true)

The nova-cell role handles services specific to a cell:

* nova-compute
* nova-compute-ironic
* nova-conductor
* nova-libvirt
* nova-novncproxy
* nova-serialproxy
* nova-spicehtml5proxy
* nova-ssh

This patch does not support using a single cell controller for managing
more than one cell. Support for sharing a cell controller will be added
in a future patch.

This patch should be backwards compatible and is tested by existing CI
jobs. A new CI job has been added that tests a multi-cell environment.

ceph-mon has been removed from the play hosts list as it is not
necessary - delegate_to does not require the host to be in the play.

Documentation will be added in a separate patch.

Partially Implements: blueprint support-nova-cells
Co-Authored-By: Mark Goddard <mark@stackhpc.com>
Change-Id: I810aad7d49db3f5a7fd9a2f0f746fd912fe03917

The idea is to factor out a role for deploying Nova related services
to cells. Since all deployments use cells, this role can be used
in both regular deployments which have just cell0 and cell1,
and deployments with many cells.

Partially Implements: blueprint support-nova-cells
Change-Id: Ib1f36ec0a773c384f2c1eac1843782a3e766045a

Several config file permissions are incorrect on the host. In general,
files should be 0660, and directories and executables 0770.

Change-Id: Id276ac1864f280554e98b937f2845bb424d521de
Closes-Bug: #1821579

Add become to all tasks that use the module "kolla_docker"

Change-Id: I4309c4011687b88ec31d739fd8f834fe2326ff10
Partial-Implements: blueprint ansible-specific-task-become

- rename action and serial to kolla_ansible and kolla_serial
- use become instead of "sudo <command>" in shell
- Remove quota for failed_when and changed_when in rabbitmq tasks

Change-Id: I78cb60168aaa40bb6439198283546b7faf33917c
Implements: blueprint migrate-to-ansible-2-2-0

Change-Id: I109d431eefa8725540b893b4dc61525b46b29c6a
Co-Authored-By: pippo <huang.zhiping@99cloud.net>

Add become to only neccesary tasks in roles:
- glance
- heat
- horizon
- keystone
- neutron
- nova
- openvswitch

Gate is also updated to use 'become' feature

Change-Id: I2f3f27306e9f384148e1ad4d54d8da2ebef34d00
Partial-Implements: blueprint ansible-specific-task-become

Actually Openstack services configuration can be overriden using many
files:
- /etc/kolla/config/<< service name >>/<< config file >>
- /etc/kolla/config/<< service name >>/<<host>>/<< config file >>
- /etc/kolla/config/global.conf
- /etc/kolla/config/database.conf
- /etc/kolla/config/messaging.conf

Only per-service configuration is actually documented here:
https://github.com/openstack/kolla-ansible/blob/master/doc/advanced-configuration.rst#L164

Allowing to globally modify service configuration can be perform too,
but it can be done in 3 different manners, all not documented:
- /etc/kolla/config/global.conf
- /etc/kolla/config/database.conf
- /etc/kolla/config/messaging.conf

database.conf and messaging.conf seems redundant with global.conf.
In order to simplify codebase it seems logical to remove them.

Documentation has been added for overriding configuration globally and
release note has been added too.

Closes-Bug: #1682479
Change-Id: I5d922dfc0d938173bad34ac64e490b78db1b7e31

Ansible task support vars directive, no need implement another one in
merge_config. This patch remove the vars directive in merge_config
action plugin.

Change-Id: I33648a2b6e39b4d49ce76eb66fbf2522721f8c68

Some roles made a bad usage of the 'node_config_directory' variable.

As described here:
https://github.com/openstack/kolla-ansible/blob/master/ansible/group_vars/all.yml#L16

'node_config_directory' is the directory to store the config files on
the destination node.

This variable MUST be changed to 'node_custom_config'.
Futhermore this will unified all roles.

Closes-Bug: #1682445
Change-Id: Id8d8a1268c79befac8938c1e0396267314b40301

Change-Id: Ida7c955d9ddf7b7dc3289001958326c38c62d0c9
Partially-implements: blueprint better-reconfigure

An operator may want to specify the location of custom config
files so that kolla can detect their location and merge
them with the default configs generated.

Partially implements: blueprint multi-project-config

Change-Id: Ibfb38d07a36dfa7fe25381adc34cc1d3cbe7d1e1

This type of per node configuration is required to support things like
availability zones for nova. As always, if this file doesnt exist it
doesnt get used so this change is safe.

TrivialFix

Change-Id: Iff8172af522c2c96e5f2c173b24a5dfd4d522ed2

The path of the template file under the same role
can easily be omitted, and we are using this omitting
in most places except those this commit is fixing.

TrivialFix
Change-Id: I6d1563e235151669d9d9268d69555aae15e31926

- See instructions in doc/nova-fake-driver.rst

Implements: blueprint nova-fake-driver

Change-Id: I553a40c2df39bdcc391eb1b8b2b8fd5f4ed48c33
Signed-off-by: Hui Kang <kangh@us.ibm.com>
Signed-off-by: Marcio D. Silva <marcios@us.ibm.com>