TODB should cascade delete interfaces and IP addresses when deleting a server via SQL

[rawlinp]

I'm submitting a ...

• bug report

Traffic Control components affected ...

• Traffic Ops

Current behavior:

When trying to delete a server via DELETE FROM server WHERE ..., you are restricted due to the ON DELETE RESTRICT FK clauses on the interface and ip_address tables. Additionally, deleting server interfaces is restricted via the ON DELETE RESTRICT FK clause on the ip_address table.

Expected behavior:

If you delete a server via DELETE FROM server WHERE ..., it should cascade delete all the server's associated interfaces and IP addresses. If you delete an interface, it should cascade delete all the interface's associated IP addresses.

Basically these FK clauses should be ON DELETE CASCADE instead of ON DELETE RESTRICT.

Minimal reproduction of the problem with instructions:

For a server that has at least one interface, attempt to delete it via the SQL query: DELETE FROM server WHERE id = .... For an interface with at least one IP address, attempt to delete it via the SQL query: DELETE FROM interface WHERE server = ... AND name = ....