When updategraph service is enabled, a special value 'default'
from DHCP response will now initialize the system with an empty
configuration instead of existing minigraph.
A DHCP response without option 224 will remain the current behavior
of skipping graph update and use existing default minigraph.
Modify minigraph parser output format so it fit DB schema
Modify configuration templates to fit new schema
Systemd services dependencies are modified so database starts before any configuration consumer
- Add a functionality to get SNMP community from DHCP (option 224)
- Add a functionality to get minigraph from http service instead of using default minigraph
- The url for graph service is passed through DHCP option 225
- This feature is by default disabled. Modify rule/config to enable it on build time, or modify /etc/sonic/graph_service_url on run time.
- Fix a bug that getting hostname from DHCP is not working correctly
