A weird template file


#1

Hi,

I am learning chef with some real cookbooks, here is the one of my learning
cookbooks link: https://github.com/stackforge/cookbook-openstack-network

Usually I add a recipe (e.g. openstack-network::openvswitch) into a node’s
run list, then run and check the result at the client node.

I found that the file /etc/quantum/quantum.conf is a different result than
expected in the template file quantum.conf.erb.

The weird part of the quantum.conf is shown as below, we can see the line
started with rpc_backend (red text):
# =========== items for agent scheduler extension =============
# Driver to use for scheduling network to DHCP agent
network_scheduler_driver =
quantum.scheduler.dhcp_agent_scheduler.ChanceScheduler

# Driver to use for scheduling router to a default L3 agent
router_scheduler_driver =
quantum.scheduler.l3_agent_scheduler.ChanceScheduler

rpc_backend = quantum.openstack.common.rpc.impl_qpid
*
*
*# Allow auto scheduling networks to DHCP agent. It will schedule non-hosted
*

However at the original template file quantum.conf.erb (shown at the
following) I cannot find the line at the same location:
*# =========== items for agent scheduler extension =============
*
# Driver to use for scheduling network to DHCP agent
network_scheduler_driver = <%=
node[“openstack”][“network”][“dhcp”][“scheduler”] %>

# Driver to use for scheduling router to a default L3 agent
router_scheduler_driver = <%=
node[“openstack”][“network”][“l3”][“scheduler”] %>

*
*
*# Allow auto scheduling networks to DHCP agent. It will schedule non-hosted
*

I tried to search the whole cookbook with the key words “rpc_backend” or
"quantum.conf.erb" but no help.

I am wondering where the line (“rpc_backend …”) comes from in the file
quantum.conf.
It has puzzled me for several days, if someone can help me out, it will be
much appreciated.

Thanks,
Sam