Issue #107: PowerTools required to install via package on CentOS 8.

.yamllint

@@ -1,6 +1,10 @@
 ---
 extends: default
+
 rules:
   line-length:
     max: 120
     level: warning
+
+ignore: |
+  .github/stale.yml

tasks/main.yml

@@ -1,6 +1,9 @@
 ---
 - import_tasks: include-vars.yml
 
+- import_tasks: setup-RedHat.yml
+  when: ansible_os_family == 'RedHat'
+
 - import_tasks: install-with-package.yml
   when: not certbot_install_from_source
 

tasks/setup-RedHat.yml

@@ -0,0 +1,20 @@
+---
+# See: https://github.com/geerlingguy/ansible-role-certbot/issues/107
+- block:
+
+  - name: Ensure dnf-plugins are installed on CentOS 8+.
+    yum:
+      name: dnf-plugins-core
+      state: present
+
+  - name: Enable DNF module for CentOS 8+.
+    shell: |
+      dnf config-manager --set-enabled PowerTools
+    args:
+      warn: false
+    register: dnf_module_enable
+    changed_when: false
+
+  when:
+    - ansible_os_family == 'RedHat'
+    - ansible_distribution_major_version | int >= 8