Use alternative apt repo way to specify nginx version

defaults/main.yml

@@ -1,6 +1,6 @@
 ---
-# Used only for Debian/Ubuntu installation, as the -t option for apt.
-nginx_default_release: ""
+# Used only for Debian/Ubuntu installation, as `add-apt-repository ppa:nginx/stable` command.
+nginx_alternative_repo: ""
 
 nginx_worker_processes: "1"
 nginx_worker_connections: "1024"

tasks/setup-Debian.yml

@@ -1,6 +1,11 @@
 ---
+- name: Add alternative nginx repo.
+  apt_repository: repo={{ nginx_alternative_repo }}
+  when: nginx_alternative_repo != ""
+
+- name: Update apt cache.
+  apt: update_cache=yes cache_valid_time=86400
+  when: nginx_alternative_repo != ""
+
 - name: Ensure nginx is installed.
-  apt:
-    pkg: nginx
-    state: installed
-    default_release: "{{ nginx_default_release }}"
+  apt: pkg=nginx state=installed