ci: reboot with ansible instead of vagrant reload

vagrant is serialized and takes a lot of time compare to simple reboot.
See the benchmarks below for 3 VMs:

[leseb@rick docker]$ time ANSIBLE_SSH_ARGS="-F
/home/leseb/reproduce-ci/tmp.zgGC7d5mIC/build/workspace/ceph-ansible/tests/functional/centos/7/docker/vagrant_ssh_config"  ansible-playbook -i /home/leseb/reproduce-ci/tmp.zgGC7d5mIC/build/workspace/ceph-ansible/tests/functional/centos/7/docker/hosts reboot.yml

PLAY [mons]
****************************************************************************************************************************************************************************************************

TASK [Gathering Facts]
*****************************************************************************************************************************************************************************************
ok: [mon1]
ok: [mon2]
ok: [mon0]

TASK [restart machine]
*****************************************************************************************************************************************************************************************
changed: [mon2]
changed: [mon1]
changed: [mon0]

TASK [wait for server to boot]
*********************************************************************************************************************************************************************************
ok: [mon2 -> localhost]
ok: [mon0 -> localhost]
ok: [mon1 -> localhost]

TASK [uptime]
**************************************************************************************************************************************************************************************************
changed: [mon2]
changed: [mon0]
changed: [mon1]

PLAY RECAP
*****************************************************************************************************************************************************************************************************
mon0                       : ok=4    changed=2    unreachable=0
failed=0
mon1                       : ok=4    changed=2    unreachable=0
failed=0
mon2                       : ok=4    changed=2    unreachable=0
failed=0

real    0m35.112s
user    0m5.737s
sys     0m1.849s

[leseb@rick docker]$ time vagrant reload
==> mon0: Halting domain...
==> mon0: Starting domain.
==> mon0: Waiting for domain to get an IP address...
==> mon0: Waiting for SSH to become available...
==> mon0: Creating shared folders metadata...
==> mon0: Rsyncing folder:
/home/leseb/reproduce-ci/tmp.zgGC7d5mIC/build/workspace/ceph-ansible/tests/functional/centos/7/docker/
=> /home/vagrant/sync
==> mon0: Machine already provisioned. Run `vagrant provision` or use
the `--provision`
==> mon0: flag to force provisioning. Provisioners marked to run always
will still run.
==> mon1: Halting domain...
==> mon1: Starting domain.
==> mon1: Waiting for domain to get an IP address...
==> mon1: Waiting for SSH to become available...
==> mon1: Creating shared folders metadata...
==> mon1: Rsyncing folder:
/home/leseb/reproduce-ci/tmp.zgGC7d5mIC/build/workspace/ceph-ansible/tests/functional/centos/7/docker/
=> /home/vagrant/sync
==> mon1: Machine already provisioned. Run `vagrant provision` or use
the `--provision`
==> mon1: flag to force provisioning. Provisioners marked to run always
will still run.
==> mon2: Halting domain...
==> mon2: Starting domain.
==> mon2: Waiting for domain to get an IP address...
==> mon2: Waiting for SSH to become available...
==> mon2: Creating shared folders metadata...
==> mon2: Rsyncing folder:
/home/leseb/reproduce-ci/tmp.zgGC7d5mIC/build/workspace/ceph-ansible/tests/functional/centos/7/docker/
=> /home/vagrant/sync
==> mon2: Machine already provisioned. Run `vagrant provision` or use
the `--provision`
==> mon2: flag to force provisioning. Provisioners marked to run always
will still run.

real    1m31.850s
user    0m7.387s
sys     0m0.796s

Reboot via Ansible: 0m35.112s
Reboot via vagrant: 1m31.850s

We save 1/3 time.

Signed-off-by: Sébastien Han <seb@redhat.com>

tests/functional/reboot.yml

@@ -0,0 +1,16 @@
+---
+- hosts: all
+  gather_facts: true
+  tasks:
+    # why sleep 2? see here: https://github.com/ansible/ansible/issues/14413
+    - name: reboot the machines
+      shell: sleep 2 && shutdown -r now
+      become: yes
+      async: 1
+      poll: 0
+
+    - name: waiting 3 minutes for the machines to come back
+      local_action: wait_for host={{ ansible_default_ipv4.address }} port=22 state=started delay=30 timeout=180
+
+    - name: uptime
+      command: uptime

tox.ini

@@ -224,7 +224,7 @@ commands=
   testinfra -n 8 --sudo -v --connection=ansible --ansible-inventory={changedir}/hosts {toxinidir}/tests/functional/tests
 
   # reboot all vms
-  vagrant reload --no-provision
+  ansible-playbook -vv -i {changedir}/hosts {toxinidir}/tests/functional/reboot.yml
 
   # wait 2 minutes for services to be ready
   sleep 120