From 98b48a3566021105baf860d2168a153a505f204c Mon Sep 17 00:00:00 2001
From: ace <ace@0xace.cc>
Date: Fri, 17 Feb 2023 18:13:18 +0300
Subject: [PATCH] add restore from backup support

---
 tasks/RedHat/data_dir.yaml | 19 ++++++++
 tasks/restore.yaml         | 88 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 tasks/RedHat/data_dir.yaml
 create mode 100644 tasks/restore.yaml

diff --git a/tasks/RedHat/data_dir.yaml b/tasks/RedHat/data_dir.yaml
new file mode 100644
index 0000000..b049e2e
--- /dev/null
+++ b/tasks/RedHat/data_dir.yaml
@@ -0,0 +1,19 @@
+- name: Create data directory
+  file:
+    path: "{{ postgresql_data_dir }}"
+    owner: "postgres"
+    group: "postgres"
+    state: directory
+
+- name: Create override directory for systemd unit
+  file:
+    path: "{{ postgresql_system_override_dir }}"
+    state: directory
+
+- name: Create override for data directory
+  copy:
+    dest: "{{ postgresql_system_override_dir }}/override.conf"
+    content: |
+      [Service]
+      Environment=PGDATA={{ postgresql_data_dir }}
+  notify: Restart PostgreSQL
diff --git a/tasks/restore.yaml b/tasks/restore.yaml
new file mode 100644
index 0000000..545ce37
--- /dev/null
+++ b/tasks/restore.yaml
@@ -0,0 +1,88 @@
+- name: Restore database
+  when: postgresql_wal_g_force_delete_and_restore
+  block:
+    - name: Stop PostgreSQL
+      systemd:
+        daemon_reload: true
+        name: "{{ postgresql_unit_name }}"
+        state: stopped
+        masked: no
+
+    - name: Force purge database directory
+      file:
+        path: "{{ postgresql_data_dir }}"
+        state: absent
+
+    - name: Recreate database directory
+      file:
+        path: "{{ postgresql_data_dir }}"
+        state: directory
+      become_user: postgres
+
+- name: Check if d folder is empty before proceeding
+  find:
+    paths: "{{ postgresql_data_dir }}"
+  register: postgresql_files_found
+
+- name: Restore database
+  when: 
+    - postgresql_files_found.matched == 0
+  block:
+    - name: Restore database dir from backup
+      shell:  "{{ postgresql_wal_g_binary_name ~ ' --config ' ~ postgresql_base_dir ~ '/' ~ postgresql_wal_g_restore_config_name ~ ' backup-fetch ' ~ postgresql_data_dir ~ ' ' ~ postgresql_wal_g_postgresql_pitr }}"
+      become_user: postgres
+    
+    - name: Include PostgreSQL configuration
+      vars:
+        postgresql_restore_command: "{{ postgresql_wal_g_binary_name ~ ' --config ' ~ postgresql_base_dir ~ '/' ~ postgresql_wal_g_restore_config_name ~ ' wal-fetch %f %p' }}"
+      include_tasks: config.yaml
+    
+    - name: Create recovery.signal file
+      file:  
+        name: "{{ postgresql_data_dir }}/recovery.signal"
+        state: touch
+      become_user: postgres
+    
+    - name: Create standby.signal file
+      file:  
+        name: "{{ postgresql_data_dir }}/standby.signal"
+        state: touch
+      become_user: postgres
+    
+    - name: Start PostgreSQL for recovery
+      systemd:
+        daemon_reload: true
+        name: "{{ postgresql_unit_name }}"
+        state: started
+        masked: no
+      register: postgresql_start_for_recovery
+    
+    - name: Ping PostgreSQL server
+      vars:
+        ansible_python_interpreter: '/usr/bin/env python3'
+      community.postgresql.postgresql_ping:
+        db: "{{ postgresql_superuser_db }}"
+        login_user: "{{ postgresql_superuser_username }}"
+        login_password: "{{ postgresql_superuser_password }}" 
+      register: postgresql_ping
+      until: postgresql_ping.is_available
+      retries: 60
+      delay: 20
+    
+    - name: debug
+      debug:
+        msg: "{{ postgresql_ping }}"
+
+    - name: Stop PostgreSQL
+      systemd:
+        daemon_reload: true
+        name: "{{ postgresql_unit_name }}"
+        state: stopped
+        masked: no
+      register: postgresql_stop
+
+    - name: Create promote trigger file
+      file:  
+        name: "{{ postgresql_promote_trigger_file }}"
+        state: touch
+      become_user: postgres