Your inventory doesn't match the current cluster configuration - Calico checks against inventory does not always work as expected

[juliohm1978]

• Version of Ansible (ansible --version): Tested with 2.9.18 and 2.10.12

ansible 2.9.18
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/juliohm/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/juliohm/.virtualenvs/ansible2.9.18/lib/python3.9/site-packages/ansible
  executable location = /home/juliohm/.virtualenvs/ansible2.9.18/bin/ansible
  python version = 3.9.7 (default, Oct 10 2021, 15:13:22) [GCC 11.1.0]

ansible 2.10.12
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/juliohm/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/juliohm/.virtualenvs/ansible/lib/python3.9/site-packages/ansible
  executable location = /home/juliohm/.virtualenvs/ansible/bin/ansible
  python version = 3.9.7 (default, Oct 10 2021, 15:13:22) [GCC 11.1.0]

• Version of Python (python --version): 3.9.7

Kubespray version (commit) (git rev-parse --short HEAD): b83e8b0

Tested with v1.15.x and v1.17.x

Network plugin used: Calico

Command used to invoke ansible:

ansible-playbook --become -i myinventory/inventory.ini -Kk cluster.yml -e kube_network_node_prefix=26

Output of ansible run:

TASK [network_plugin/calico : Check if inventory match current cluster configuration] *********************************************************************************************
fatal: [k8s-master01-lab-20190604.dis.tjpr.jus.br]: FAILED! => {
    "assertion": "calico_pool_conf.spec.blockSize == (calico_pool_blocksize | default(kube_network_node_prefix))",
    "changed": false,
    "evaluated_to": false,
    "msg": "Your inventory doesn't match the current cluster configuration"
}

Anything else do we need to know:
In our particular scenario, Calico's pool blockSize varies from the default 24. Initially, the playbook fails because of the different values. But as we pass -e kube_network_node_prefix=26 to the command line, the playbook also fails.

Debugging further, I found the assertion being made does not match, even when both values in the boolean equation are 26.

calico_pool_conf.spec.blockSize == (calico_pool_blocksize | default(kube_network_node_prefix))

As a downside of Yaml parsing, one these values is a string and the other is an integer. Ansible needs to compare them with equal types. The workaround I found is to change the assertion to

calico_pool_conf.spec.blockSize|string == (calico_pool_blocksize | default(kube_network_node_prefix | string))