Description of problem:
When deploying an overcloud with a large number (in this case 117) of predictable IP addresses in the network-environment.yaml, the deployment fails with 'CREATE_FAILED  Resource CREATE failed: resources[0]: Property error: resources.NetworkConfig.properties: Property ControlPlaneDefaultRoute not assigned' despite ControlPlaneDefaultRoute being defined. When using a smaller number (in this case 59) of predictable IP addresses, the deployment is successful.

How reproducible:
Every time there are a large number of predictable IP addresses

Steps to Reproduce:
1. Create heat templates including a large network-environment.yaml
2. Attempt to deploy

Actual results:
Deploy fails with: 'CREATE_FAILED  Resource CREATE failed: resources[0]: Property error: resources.NetworkConfig.properties: Property ControlPlaneDefaultRoute not assigned'

Expected results:
Deploy succeeds

Additional info:
Upon further investigation, this error is seen in /var/log/mistral/api.log just before the deploy fails:
2017-03-22 13:47:02.851 5076 ERROR oslo_db.sqlalchemy.exc_filters DataError: (1406, u"Data too long for column 'variables' at row 1")

A workaround was to change the column type from text to longtext. After doing this, the larger deployment succeeded.

MariaDB [mistral]> SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'environments_v2' AND COLUMN_NAME = 'variables';
+-----------+
| DATA_TYPE |
+-----------+
| text      |
+-----------+

MariaDB [mistral]> ALTER TABLE environments_v2 MODIFY variables LONGTEXT;