Description of problem:

There seems to be an inconsistency in filtering resources [1] using boolean options.

For example, when I try to filter out members of a pool using admin_state_up boolean value then values like 'true' and 'false' work as expected.

However, when I want to filter out all members using the backup (or other boolean fields like 'enabled') field then 'true'/'false' values do not work as expected. The user must use the values stored in the database 1/0 instead.

curl -H 'Content-Type: application/json' \
     -H 'Accept: application/json' \
     -H 'X-Auth-Token: XXXXX' \
     http://xxxxx/load-balancer/v2.0/lbaas/pools/XXXX/members?backup=true

I get non-backup members from the pool in the response. See the attached file for more examples. In the file, I work with 1 backup member and 2 default members.

[1] https://docs.openstack.org/api-ref/load-balancer/v2/#filtering-and-column-selection