Flatcar OS detection failure

[kopiczko]

What steps did you take and what happened:

$ make FLATCAR_CHANNEL=stable FLATCAR_VERSION=3227.2.2 build-qemu-flatcar

...

    qemu: TASK [node : Copy etcd network tuning script] **********************************
    qemu: fatal: [default]: FAILED! => {"changed": false, "checksum": "38b8f0b3ba1cfc04bc8d6cdafd7f141a0fef6e61", "msg": "Destination /usr/local/bin not writable"}
    qemu:
    qemu: PLAY RECAP *********************************************************************
    qemu: default                    : ok=9    changed=5    unreachable=0    failed=1    skipped=126  rescued=0    ignored=0
    qemu:
==> qemu: Provisioning step had errors: Running the cleanup provisioner, if present...
==> qemu: Deleting output directory...
Build 'qemu' errored after 5 minutes 51 seconds: Error executing Ansible: Non-zero exit status: exit status 2

What did you expect to happen:

Build an image.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

It is because of this line in images/capi/ansible/roles/node/defaults/main.yml

external_binary_path: "{{ '/opt/bin' if ansible_os_family == 'Flatcar' else '/usr/local/bin' }}"

It doesn't detect Flatcar correctly.

Environment:

Project (Image Builder for Cluster API, kube-deploy/imagebuilder, konfigadm):

Additional info for Image Builder for Cluster API related issues:

• OS (e.g. from /etc/os-release, or cmd /c ver):
• Packer Version:
• Packer Provider:
• Ansible Version:
• Cluster-api version (if using):
• Kubernetes version: (use kubectl version):

/kind bug