Update qgroup setup to be more explicit

The default qgroup setup was setting the qgroup limits to none which
allows the system to dynamical expand or contract. While this works
there can be a lag between the time it takes to grow vs the time it
takes to hit the limit. This change sets the limits accordingly should a
deployer not have a container specific limit set already.

Change-Id: Iea2498bfe1c391f4b4bee295c8f04b2655f404d9

tasks/main.yml

@@ -29,6 +29,31 @@
     - skip_ansible_lint
     - always
 
+- name: Pull filesystem information
+  command: "btrfs filesystem show --raw /var/lib/machines"
+  changed_when: false
+  register: filesystem
+  delegate_to: "{{ physical_host }}"
+  tags:
+    - skip_ansible_lint
+    - always
+
+- name: Set qgroup space fact
+  set_fact:
+    nspawn_host_qgroup_space_limit: "{{ filesystem.stdout.strip().splitlines()[-1].split()[3] }}"
+  when:
+    - nspawn_host_qgroup_space_limit == 'none'
+  tags:
+    - always
+
+- name: Set qgroup compression fact
+  set_fact:
+    nspawn_host_qgroup_compression_limit: "{{ filesystem.stdout.strip().splitlines()[-1].split()[3] }}"
+  when:
+    - nspawn_host_qgroup_compression_limit == 'none'
+  tags:
+    - always
+
 - name: Set facts
   set_fact:
     nspawn_systemd_version: "{{ systemd_version.stdout_lines[0].split()[-1] }}"