prepare_host.yaml: new apt pkg style and tab fixed

- New apt multipackage style

- Tabulation in `templates/interfaces.j2` and in `/etc/lvm/lvm.conf`
  line fixed: in Debian buster tabulation is used to indent this config
  files by default.

MIGRATION.md

@@ -23,7 +23,7 @@ On the hosts:
 |`roles/service`     | **YES**   | **YES**  | NO          | Changes in Ansible built-in `apt` module.                                                |
 |`roles/ssh_server`  | **YES**   | **YES**  | NO          | `lxc_ssh.py` --> `ssh_lxc.py`.                                                           |
 |`roles/ca`          | **YES**   | ReadNote | NO          | Changes in Ansible built-in `apt` module. Needs update of `ca_manager` to [1] to work.   |
-|`prepare_host.yaml` | **YES**   | NO       | NO          | Install `python3` and `python3-lxc` instead of version 2.                                |
+|`prepare_host.yaml` | **YES**   | **YES**  | NO          | Debian stretch --> buster and Python 2 --> 3                                             |
 |`roles/ldap`        | NO        | NO       | NO          |                                                                                          |
 |`roles/nginx`       | NO        | NO       | NO          |                                                                                          |
 |`roles/projects`    | NO        | NO       | NO          |                                                                                          |

prepare_host.yaml

@@ -8,14 +8,13 @@
   tasks:
     - name: install lxc related packages
       apt:
-        name: "{{ item }}"
+        pkg:
+          - lxc
+          - python3
+          - python3-lxc
         state: present
         update_cache: yes
         cache_valid_time: 3600
-      with_items:
-        - lxc
-        - python3
-        - python3-lxc
 
     - name: install common lxc filesystem support
       apt:
@@ -24,13 +23,12 @@
 
     - name: install network bridge utilities
       apt:
-        name: "{{ item }}"
+        pkg:
+          - bridge-utils
+          - vlan
         state: present
         update_cache: yes
         cache_valid_time: 3600
-      with_items:
-        - bridge-utils
-        - vlan
       notify: restart networking
     # We should fix this bug. We really should. It's a bug.
     # Bridge-utils requires a complete system reboot to enable the new bridge.
@@ -43,19 +41,18 @@
 
     - name: install utilities
       apt:
-        name: "{{ item }}"
+        pkg:
+          - vim
+          - htop
         state: present
         update_cache: yes
         cache_valid_time: 3600
-      with_items:
-        - vim
-        - htop
 
     - name: enable lvm wipe signature
       lineinfile:
         dest: /etc/lvm/lvm.conf
         state: present
-        line: "        wipe_signatures_when_zeroing_new_lvs = 0"
+        line: "	wipe_signatures_when_zeroing_new_lvs = 0"
         regexp: '^\s*.+wipe_signatures_when_zeroing_new_lvs = '
       notify: restart lvm
   handlers:

templates/interfaces.j2

@@ -10,12 +10,12 @@ iface lo inet loopback
 # The primary network interface
 auto br0
 iface br0 inet manual
-        bridge_ports {{ ansible_default_ipv4.alias }}.{{ virtual_machine_vlan }}
-        bridge_fd 1
+	bridge_ports {{ ansible_default_ipv4.alias }}.{{ virtual_machine_vlan }}
+	bridge_fd 1
 
 auto {{ ansible_default_ipv4.alias }}
 iface {{ ansible_default_ipv4.alias }} inet static
 	address {{ ansible_default_ipv4.address }}
-        gateway {{ hostvars | ip_from_inventory('management_gateway') }}
-        netmask 255.255.255.0
+	gateway {{ hostvars | ip_from_inventory('management_gateway') }}
+	netmask 255.255.255.0
 	vlan-raw-device {{ ansible_default_ipv4.alias }}