Refactor PostgreSQL schema import

We take advantage of the community.postgres modules, and do a query
for 'mandatory' in 'dbversion', as is done in the mysql tasks. If
the query fails, we're going to assume the database has not been
populated yet, and populate it in the rescue section.

The query and schema import happens from the zabbix server, it
serves as a good test of verifying permissions previously created.

roles/zabbix_server/tasks/postgresql.yml

@@ -59,37 +59,33 @@
         db: "{{ zabbix_server_dbname }}"
         name: timescaledb
 
-- name: "PostgreSQL | Create schema"
-  ansible.builtin.shell: |
-    set -euxo pipefail
-    FILE={{ is_legacy_version | ternary('create', 'server') }}.sql
-    cd {{ is_legacy_version | ternary(legacy_path, modern_path) }}
-    if [ -f ${FILE}.gz ]
-      then zcat ${FILE}.gz > /tmp/create.sql
-    else
-      cp ${FILE} /tmp/create.sql
-    fi
-    cat /tmp/create.sql | psql -h '{{ zabbix_server_dbhost }}' \
-    -U '{{ zabbix_server_dbuser }}' \
-    -d '{{ zabbix_server_dbname }}' \
-    -p '{{ zabbix_server_dbport }}'
-    touch /etc/zabbix/schema.done
-    rm -f /tmp/create.sql
-  args:
-    creates: /etc/zabbix/schema.done
-    executable: /bin/bash
-    warn: "{{ produce_warn | default(omit) }}"
-  environment:
-    PGPASSWORD: "{{ zabbix_server_dbpassword }}"
-  become: true
-  vars:
-    is_legacy_version: "{{ zabbix_server_version is version('6.0', '<') }}"
-    legacy_path: /usr/share/doc/zabbix-server-pgsql
-    modern_path: /usr/share/zabbix-sql-scripts/postgresql
-  when:
-    - zabbix_server_database_sqlload
+- name: "PostgreSQL verify or create schema"
+  when: zabbix_server_database_sqlload
   tags:
     - database
+  block:
+    - name: "PostgreSQL | Get current database version"
+      community.postgresql.postgresql_query:
+        login_user: "{{ zabbix_server_dbuser }}"
+        login_password: "{{ zabbix_server_dbpassword }}"
+        login_host: "{{ zabbix_server_dbhost }}"
+        port: "{{ zabbix_server_dbport }}"
+        db: "{{ zabbix_server_dbname }}"
+        query: 'SELECT mandatory FROM dbversion'
+  rescue:
+    - name: "PostgreSQL | Import schema"
+      community.postgresql.postgresql_db:
+        login_user: "{{ zabbix_server_dbuser }}"
+        login_password: "{{ zabbix_server_dbpassword }}"
+        login_host: "{{ zabbix_server_dbhost }}"
+        port: "{{ zabbix_server_dbport }}"
+        db: "{{ zabbix_server_dbname }}"
+        state: restore
+        target: "{{ is_legacy_version | ternary(legacy_path, modern_path) }}"
+      vars:
+        is_legacy_version: "{{ zabbix_server_version is version('6.0', '<') }}"
+        legacy_path: /usr/share/doc/zabbix-server-pgsql/create.sql.gz
+        modern_path: /usr/share/zabbix-sql-scripts/postgresql/server.sql.gz
 
 - name: "PostgreSQL | Create TimescaleDB hypertables"
   ansible.builtin.shell: |