Use a Python script to set PSQL facts (version and dbdir)

.gitignore

@@ -1,4 +1,3 @@
 .DS_Store
 *.pyc
 __pycache__
-files/

defaults/main.yaml

@@ -1,20 +1,8 @@
 ---
-postgresql_version: "{{ vars.postgresql.version }}"
+postgresql_version: "{{ ansible_local.postgresql.version | default(16) }}"
 postgresql:
-  version: 13 # Is ignored on FreeBSD Proservers
-  prefix:
-    config: >-
-      {%- if ansible_system == 'Linux' -%}
-        /etc/postgresql/{{ postgresql_version }}/main/conf.d
-      {%- elif ansible_system == 'FreeBSD' -%}
-        {%- if postgresql_version == "15" -%}
-           /var/db/postgres/data{{ postgresql_version }}
-      {%- else -%}
-           /var/db/postgresql/data{{ postgresql_version }}
-      {%- endif -%}
-      {%- else -%}
-        /usr/local/etc/main/conf.d
-      {%- endif -%}
+  version: "{{ postgresql_version }}"
+  prefix: "{{ ansible_local.postgresql.prefix | default('') }}"
   users: {}
   privileges: {}
   databases:

files/postgresql.fact.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+import os
+import re
+import json
+import subprocess
+
+class PostgresqlFacts:           
+    def get_os_family(self) -> str:
+        if os.path.exists("/etc/os-release"):
+            os_vars = {}
+            with open("/etc/os-release", "r", encoding="utf-8") as os_release:
+                for line in os_release.readlines():
+                    key, value = line.split("=")
+                    os_vars.update({key: value})
+            if os_vars.get("ID_LIKE"):
+                os_family = str(os_vars.get("ID_LIKE")).lower().strip()
+            else:
+                os_family = str(os_vars.get("ID")).lower().strip()
+        else:
+            os_family = re.findall(r"debian|freebsd", os.uname().version.lower())
+            if len(os_family) == 0:
+                raise OSError(f"Unsupported OS family: {os.uname().version}")
+            else:
+                os_family = os_family[0]
+        if os_family == "debian" or os_family == "freebsd":
+            return os_family
+        else:
+            raise OSError(f"Unsupported OS family: {os_family}")
+
+    def get_postgresql_version(self) -> int:
+        os_family = self.get_os_family()
+        if os_family == "debian":
+            command='apt-cache search --names-only "^postgresql-[0-9]+$" | grep -Po "[0-9]+"'
+        else:
+            command='psql --version | sed "s/^.*\\([0-9][0-9]\\).*$/\\1/"'
+        command_output = subprocess.run(command, shell=True, capture_output=True)
+        if len(command_output.stdout) > 0:
+            return int(command_output.stdout.decode().strip())
+        else:
+            raise OSError(f"Error detecting the PostgreSQL version: {command_output.stderr.decode()}")
+
+    def get_postgresql_dbdir(self) -> str:
+        os_family = self.get_os_family()
+        version = self.get_postgresql_version()
+        if os_family == "debian":
+            dbdir = f"/etc/postgresql/{version}/main/conf.d"
+        else:
+            if version >= 15:
+                dbdir = f"/var/db/postgres/data{version}"
+            else:
+                dbdir = f"/var/db/postgresql/data{version}"
+        return dbdir
+
+    def generate_postgresql_facts(self) -> dict:
+        return {
+                'version': str(self.get_postgresql_version()),
+                'prefix': {"config": self.get_postgresql_dbdir()},
+                }
+
+class Facts:
+    def __str__(self):
+        return json.dumps(PostgresqlFacts().generate_postgresql_facts())
+
+if __name__ == '__main__':
+    print(Facts())

tasks/main.yaml

@@ -1,7 +1,6 @@
 ---
-- name: Determine the PostgreSQL version (FreeBSD Proserver)
-  ansible.builtin.include_tasks: postgresql_version.yaml
-  when: ansible_system == 'FreeBSD'
+- name: Set the PostgreSQL facts
+  ansible.builtin.include_tasks: postgresql_fact.yaml
 
 - name: Install PostgreSQL (Linux)
   ansible.builtin.include_tasks: install.yaml

tasks/postgresql_fact.yaml

@@ -0,0 +1,33 @@
+---
+- name: Update apt cache (Debian-based)
+  changed_when: no
+  check_mode: no
+  when: "ansible_os_family == 'Debian'"
+  ansible.builtin.apt:
+    update_cache: yes
+
+- name: Create directory for Ansible facts
+  loop:
+    - "/etc/ansible"
+    - "/etc/ansible/facts.d"
+  check_mode: no
+  ansible.builtin.file:
+    mode: "0755"
+    owner: root
+    path: "{{ item }}"
+    state: directory
+
+- name: Template PostrgreSQL facts
+  check_mode: no
+  ansible.builtin.copy:
+    owner: root
+    src: postgresql.fact.py
+    dest: "/etc/ansible/facts.d/postgresql.fact"
+    mode: a+x
+  register: postgresql_template_fact_result
+
+- name: Reload facts
+  check_mode: no
+  when: postgresql_template_fact_result.changed
+  changed_when: yes
+  ansible.builtin.setup: {}