[CI] Do not set ansible_python_interpreter for Zuul

Zuul 4.6.0 does not allow to set ansible_python_interpreter. [1]
Instead, with the current Zuul and Ansible, this should be
automatically set to the proper python.

This patch is required to restore the jobs which are ignored
otherwise. [2] [3]

Additionally, this change avoids the use of Ansible's pip
module because it tries to use setuptools from the
ansible_python_interpreter first even if another executable is
set.

[1] http://lists.openstack.org/pipermail/openstack-discuss/2021-June/023291.html
[2] http://lists.openstack.org/pipermail/openstack-discuss/2021-June/023326.html
[3] http://lists.openstack.org/pipermail/openstack-discuss/2021-June/023321.html

Change-Id: Ib74eecd46617af51e23a3ccad664767b1bf6e04f

Author: yoctozepto

.zuul.d/base.yaml

@@ -110,7 +110,6 @@
       - ^tox\.ini$
     vars:
       publisher: false
-      ansible_python_interpreter: python3
     extra-vars:
       kolla_logs_dir: "{{ zuul_output_dir }}/logs/kolla"
       kolla_build_logs_dir: "{{ kolla_logs_dir }}/build"

tests/playbooks/pre.yml

@@ -38,12 +38,11 @@
       when:
         ansible_os_family == "Debian"
 
+    - name: Create virtualenv
+      command: python3 -m virtualenv {{ virtualenv_path }} --python python3
+
     - name: Install kolla
-      pip:
-        name: .
-        chdir: "{{ zuul.project.src_dir }}"
-        virtualenv: "{{ virtualenv_path }}"
-        virtualenv_python: python3
+      command: "{{ virtualenv_path }}/bin/python -m pip install {{ zuul.project.src_dir }}"
 
     - name: Configure Docker repo for Debian/Ubuntu
       block:

tests/playbooks/publish.yml

@@ -1,12 +1,9 @@
 ---
 - hosts: all
+  vars:
+    # NOTE(yoctozepto): We need Docker SDK, the best source is Kolla venv.
+    ansible_python_interpreter: "{{ virtualenv_path }}/bin/python"
   tasks:
-    - name: Ensure docker python SDK is installed
-      become: true
-      pip:
-        name: "docker"
-        state: present
-
     - name: List all containers
       docker_host_info:
         images: yes