Karaf cli command to display the hwvtep cache data

Karaf cli command to display the hwvtep cache data

JIRA: OVSDB-482

The hwvtep configuration data is pushed to the tor by the hwvtep plugin.
The hwvtep plugin has the caches (config and operational caches) which holds
the hwvtep configuration. The hwvtep configuration push to the tor is also
dependent on the data that is present in caches.
For ex : To push the vlanbinding data to the PhysicalPort , the operational
cache is checked first, if present in the operational cache get the uuid of
that PhysicalPort and the send/push the vlanbinding to the tor.

Today it is hard to know/check what is present in the cache. In case if there
any issue in updating the cache, it is hard to debug/analyse the issue as no way
to know what is present in the cache.

If we have mechanism/cli command which gives the information of the hwvtep
caches, it will be very helpful to debug or analyze such cache missing issues.

This is for adding the karaf cli command which displays the hwvtep caches contents.
This command has two options :
1. Hwvtep nodeid as the input. Displays cache information of input hwvtep node.
2. Without any input. Displays the cache information of all hwvtep nodes.

Change-Id: I4301a784d83aa28f5ef4737fc44d052f323e11df
Signed-off-by: Chandra Shekar S <chandra.shekar.s@ericsson.com>