New variable "monitored_packages_predepends"

Install packages which are necessary for this role (needed for Alpine
Linux's 'shadow' package)

defaults/main.yml

@@ -8,6 +8,7 @@ monitored_homedir: /var/lib/nagios
 monitored_shell: /bin/bash
 
 monitored_packages_install: True
+monitored_packages_predepends: []
 monitored_packages_additional: []
 monitored_packages_additional_nrpe: []
 monitored_packages_additional_ssh: []

tasks/main.yml

@@ -12,7 +12,12 @@
     - "{{ (ansible_distribution|lower).split(' ')[0] }}-{{ (ansible_distribution_major_version|lower).split(' ')[0] }}.yml"
     - "{{ (ansible_distribution|lower).split(' ')[0] }}.yml"
     - "{{ (ansible_os_family|lower).split(' ')[0] }}.yml"
-    - "defaults.yml"
+
+- name: "Install dependencies"
+  package:
+    name: "{{ monitored_packages_predepends }}"
+    state: latest
+  when: monitored_packages_predepends
 
 - name: "INCLUDE: Create monitoring user"
   import_tasks: user.yml