Check the presence of the zabbix-release package before trying to install it.

defaults/main.yml

@@ -5,6 +5,10 @@ zabbix_repo_version: '4.0'
 zabbix_agent_ubuntu_repo: 'https://repo.zabbix.com/zabbix/{{ zabbix_repo_version }}/{{ ansible_distribution | lower }}/pool/main/z/zabbix-release/zabbix-release_{{ zabbix_repo_version }}-2+{{ ansible_distribution_release }}_all.deb'
 zabbix_agent_centos_repo: 'https://repo.zabbix.com/zabbix/{{ zabbix_repo_version }}/rhel/{{ ansible_distribution_major_version }}/x86_64/zabbix-release-{{ zabbix_repo_version }}-1.el7.noarch.rpm'
 
+zabbix_agent_packages:
+  - 'zabbix-agent'
+  - 'zabbix-release'
+
 zabbix_agent_conf_dir: /etc/zabbix
 zabbix_agent_include_conf_dir: '{{ zabbix_agent_conf_dir }}/zabbix_agentd.d'
 zabbix_agent_log_dir: '/var/log/zabbix'

tasks/main.yml

@@ -1,4 +1,11 @@
 ---
+- name: Check if the zabbix repository is installed
+  package_facts:
+    manager: "auto"
+  when:
+    - zabbix_agent_install | bool
+  tags: [ 'zabbix', 'zabbix_agent' ]
+
 - import_tasks: zabbix-agent-deb.yml
   when:
     - zabbix_agent_install | bool

tasks/zabbix-agent-deb.yml

@@ -2,14 +2,15 @@
 - name: Repository and packages, deb/ubuntu
   block:
   - name: Install the repository 
-    apt: deb={{ zabbix_agent_ubuntu_repo }} state=latest
+    apt: deb={{ zabbix_agent_ubuntu_repo }} state=present
     register: update_apt_cache
+    when: "'zabbix-release' not in ansible_facts.packages"
 
   - name: Update the apt cache if we just installed the repository
     apt: update_cache=yes
-    when: update_apt_cache is changed
+    when: update_apt_cache is defined and update_apt_cache is changed
 
   - name: Install the Zabbix agent package
-    apt: pkg=zabbix-agent state=latest  cache_valid_time=1800
+    apt: pkg={{ zabbix_agent_packages }} state=latest  cache_valid_time=1800
 
   tags: [ 'zabbix', 'zabbix_agent' ]

tasks/zabbix-agent-rh.yml

@@ -2,9 +2,10 @@
 - name: Repository and packages, RH/CentOS
   block:
   - name: Install the repository 
-    yum: name={{ zabbix_agent_centos_repo }} state=latest
+    yum: name={{ zabbix_agent_centos_repo }} state=present
+    when: "'zabbix-release' not in ansible_facts.packages"
 
   - name: Install the Zabbix agent package
-    yum: name=zabbix-agent state=latest
+    yum: name={{ zabbix_agent_packages }} state=latest
 
   tags: [ 'zabbix', 'zabbix_agent' ]