Installation of stock or external PostgreSQL on CentOS 7 and 8

postgresql/tasks/packages.yml

 ---
 
-- name: Print PostgreSQL version
-  debug:
-    msg: '{{ postgresql_version | replace(".", "") }}'
-
-- name: Install PostgreSQL {{ postgresql_version }} packages for CentOS 7
+- name: Install ancillary packages for CentOS 7
   yum:
     conf_file: '/etc/yum.conf'
-    name: 
+    name:
       - libselinux-python
       - python-pip
-      - 'postgresql{{ postgresql_version | replace(".", "") }}'
-      - 'postgresql{{ postgresql_version | replace(".", "") }}-server'
-    state: present
   when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "7")
 
-- name: Install PostgreSQL 10.6 packages for CentOS 8
+- name: Install PostgreSQL {{ external_postgresql_version }} packages for CentOS 7
+  yum:
+    conf_file: '/etc/yum.conf'
+    name: 
+      - 'postgresql{{ external_postgresql_version | replace(".", "") }}'
+      - 'postgresql{{ external_postgresql_version | replace(".", "") }}-server'
+    state: present
+  when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "7" and not use_distribution_postgresql)
+
+- name: Install PostgreSQL 9.2 packages for CentOS 7
+  yum:
+    conf_file: '/etc/yum.conf'
+    name:
+      - postgresql
+      - postgresql-server
+    state: present
+  when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "7" and use_distribution_postgresql)
+
+- name: Install ancillary packages for CentOS 8
   dnf:
     conf_file: '/etc/dnf/dnf.conf'
     name:
       - python3-libselinux
       - python3-pip
+    state: present
+  when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "8")
+
+- name: Install PostgreSQL {{ external_postgresql_version }} packages for CentOS 8
+  dnf:
+    conf_file: '/etc/dnf/dnf.conf'
+    name:
+      - 'postgresql{{ external_postgresql_version | replace(".", "") }}'
+      - 'postgresql{{ external_postgresql_version | replace(".", "") }}-server'
+    state: present
+  when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "8" and not use_distribution_postgresql)
+
+- name: Install PostgreSQL 10 packages for CentOS 8
+  dnf:
+    conf_file: '/etc/dnf/dnf.conf'
+    name:
       - postgresql
       - postgresql-server
     state: present
-  when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "8")
+  when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "8" and use_distribution_postgresql)
 
 ...