Enable nova fake driver in nova containers

- 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>

1 files changed, 34 insertions, 0 deletions

diff --git a/doc/nova-fake-driver.rst b/doc/nova-fake-driver.rst
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+Nova Fake Driver
+================
+
+One common question from OpenStack operators is that "how does the control plane
+(e.g., database, messaging queue, nova-scheduler ) scales?". To answer this
+question, operators setup Rally to drive workload to the OpenStack cloud.
+However, without a large number of nova-compute nodes, it becomes difficult to
+exercise the control performance.
+
+Given the built-in feature of Docker container, Kolla enables standing up many
+many of nova-compute nodes with nova fake driver on a single host. For example,
+we can create 100 nova-compute containers on a real host to simulate the
+100-hypervisor workload to the nova-conductor and the messaging queue.
+
+Use nova-fake driver
+---------------------
+
+Nova fake driver can not work with all-in-one deployment. This is because the
+fake neutron-openvswitch-agent for the fake nova-compute container conflicts
+with neutron-openvswitch-agent on the compute nodes. Therefore, in the inventory
+the network node must be different than the compute node.
+
+By default, Kolla uses libvirt driver on the compute node. To use nova-fake
+driver, edit the following parameters in ansible/group_vars or in the
+command line options.
+
+::
+
+  enable_nova_fake: "yes"
+  num_nova_fake_per_node: 5
+
+Each compute nodes will run 5 nova-compute containers and 5
+neutron-plugin-agent containers. When booting instance, there will be no
+real instances created. But "nova list" shows the fake instances.