Initial code

defaults/main.yml

+zabbix_agent_url: 'http://repo.zabbix.com/zabbix/3.0/ubuntu/pool/main/z/zabbix-release/zabbix-release_3.0-1+xenial_all.deb'

tasks/install.yml

+---
+# file: roles/zabbix_agent/tasks/main.yml
+
+- name: "Download Zabbix Agent"
+  get_url:
+    url: '{{ zabbix_agent_url }}'
+    dest: '/tmp/zabbix_agent.deb'
+
+- name: "Install Zabbix Agent"
+  shell: 'dpkg -i /tmp/zabbix_agent.deb'
+
+- name: "Upgrade Zabbix-Agent"
+  apt:
+    upgrade: yes
+    update_cache: yes

tasks/main.yml

+---
+# file: roles/zabbix_agent/tasks/main.yml
+
+- name: "Zabbix Agent Role"
+  set_fact: role_zabbix_agent_started=true
+  tags: always
+
+- block:
+
+  - include: install.yml
+
+  - name: 'Remember that this role had been run'
+    set_fact: role_zabbix_agent_completed=true
+    tags: always
+
+  when: '"zabbix_agent" not in excluded_roles and role_zabbix_agent_completed is not defined'