automatic architecture detection

tasks/setup-Debian.yml

@@ -44,6 +44,13 @@
     warn: false
   when: add_repository_key is failed
 
+- name: Get DEB architecture
+  shell: dpkg --print-architecture
+  register: docker_apt_arch
+  check_mode: false
+  changed_when: false
+  failed_when: false
+
 - name: Add Docker repository.
   apt_repository:
     repo: "{{ docker_apt_repository }}"