Use Python2/3 to detect ansible_python_interpreter

With the test it is not needed to pin down the python interpreter for ansible
modules. It is therefore possible to use a Python2 version on Fedora-27 and
a Python3 version on Fedora-26.

roles/ipaclient/tasks/install.yml

@@ -7,6 +7,10 @@
     state: present
   with_items: "{{ ipaclient_packages }}"
 
+- name: Install - Include Python2/3 import test
+  include: "{{role_path}}/tasks/python_2_3_test.yml"
+  static: yes
+
 - name: Install - IPA discovery
   ipadiscovery:
     domain: "{{ ipaclient_domain | default(omit) }}"

roles/ipaclient/tasks/python_2_3_test.yml

+- block:
+  - name: Verify Python3 import
+    command: python3 -c "from ipapython.version import NUM_VERSION"
+    register: py3test
+    failed_when: False
+
+  - name: Set python interpreter to 3
+    set_fact:
+      ansible_python_interpreter: "/usr/bin/python3"
+    when: py3test.rc == 0
+
+  - name: Set python interpreter to 2
+    set_fact:
+      ansible_python_interpreter: "/usr/bin/python2"
+    when: py3test.failed or py3test.rc != 0

roles/ipaclient/tasks/uninstall.yml

 ---
 # tasks to uninstall IPA client
 
+- name: Uninstall - Include Python2/3 import test
+  include: "{{role_path}}/tasks/python_2_3_test.yml"
+  static: yes
+
 - name: Uninstall - Uninstall IPA client
   ipaclient:
     state: absent

roles/ipaclient/vars/Fedora-25.yml

 ipaclient_packages: [ "ipa-client", "libselinux-python" ]
-ansible_python_interpreter: '/usr/bin/python2'
+#ansible_python_interpreter: '/usr/bin/python2'
\ No newline at end of file

roles/ipaclient/vars/Fedora-26.yml

 ipaclient_packages: [ "ipa-client", "libselinux-python" ]
-ansible_python_interpreter: '/usr/bin/python2'
+#ansible_python_interpreter: '/usr/bin/python2'
\ No newline at end of file

roles/ipaclient/vars/RedHat-7.3.yml

 # defaults file for ipaclient
 # vars/rhel.yml
 ipaclient_packages: [ "ipa-client", "ipa-admintools", "libselinux-python" ]
-ansible_python_interpreter: '/usr/bin/python2'
+#ansible_python_interpreter: '/usr/bin/python2'

roles/ipaclient/vars/RedHat-7.yml

 # defaults file for ipaclient
 # vars/rhel.yml
 ipaclient_packages: [ "ipa-client", "libselinux-python" ]
-ansible_python_interpreter: '/usr/bin/python2'
+#ansible_python_interpreter: '/usr/bin/python2'

roles/ipaclient/vars/default.yml

 # defaults file for ipaclient
 # vars/default.yml
 ipaclient_packages: [ "ipa-client", "libselinux-python" ]
-ansible_python_interpreter: '/usr/bin/python3'
+#ansible_python_interpreter: '/usr/bin/python3'