feat: rework logging and rotation rules

roles/postgres/defaults/main.yml

@@ -26,3 +26,26 @@ postgres_effective_cache_size: 1GB
 postgres_maintenance_work_mem: 64MB
 postgres_work_mem: 4MB
 postgres_max_connections: 100
+
+# Logging configuration
+# Backend: 'journald' (systemd journal) or 'file' (traditional log files)
+postgres_log_backend: journald
+
+# Logging settings (apply to both backends)
+postgres_log_min_duration_statement: -1 # -1 disables, 0 logs all, >0 logs slow queries (ms)
+postgres_log_line_prefix: "%m [%p] %q%u@%d " # timestamp [pid] user@database
+postgres_log_timezone: UTC
+
+# File backend settings (only used when postgres_log_backend: file)
+postgres_log_destination: stderr # stderr|csvlog|syslog
+postgres_logging_collector: "on" # Enable log file collection
+postgres_log_directory: log # Relative to data directory
+postgres_log_filename: postgresql-%Y-%m-%d_%H%M%S.log
+postgres_log_rotation_age: 1d # Rotate after this time (0 disables)
+postgres_log_rotation_size: 100MB # Rotate after this size (0 disables)
+postgres_log_truncate_on_rotation: "off" # Overwrite old log files with same name
+
+# Logrotate configuration (only used when postgres_log_backend: file)
+postgres_logrotate_rotate: 14 # Keep 14 days of logs
+postgres_logrotate_frequency: daily # daily|weekly|monthly
+postgres_logrotate_compress: true # Compress rotated logs

roles/postgres/tasks/main.yml

@@ -73,6 +73,21 @@
     enabled: true
     state: started
 
+- name: Deploy logrotate configuration for PostgreSQL
+  ansible.builtin.template:
+    src: logrotate-postgresql.j2
+    dest: /etc/logrotate.d/postgresql
+    owner: root
+    group: root
+    mode: "0644"
+  when: postgres_log_backend == 'file'
+
+- name: Remove logrotate configuration when using journald
+  ansible.builtin.file:
+    path: /etc/logrotate.d/postgresql
+    state: absent
+  when: postgres_log_backend == 'journald'
+
 - name: Set PostgreSQL admin user password
   community.postgresql.postgresql_user:
     name: "{{ postgres_admin_user }}"

roles/postgres/templates/custom.conf.j2

@@ -11,3 +11,26 @@ effective_cache_size = {{ postgres_effective_cache_size }}
 maintenance_work_mem = {{ postgres_maintenance_work_mem }}
 work_mem = {{ postgres_work_mem }}
 max_connections = {{ postgres_max_connections }}
+
+# Logging configuration
+{% if postgres_log_backend == 'journald' %}
+# Log to systemd journal via stderr (journald captures it automatically)
+log_destination = 'stderr'
+logging_collector = off
+{% else %}
+# Log to files
+log_destination = '{{ postgres_log_destination }}'
+logging_collector = {{ postgres_logging_collector }}
+log_directory = '{{ postgres_log_directory }}'
+log_filename = '{{ postgres_log_filename }}'
+log_rotation_age = {{ postgres_log_rotation_age }}
+log_rotation_size = {{ postgres_log_rotation_size }}
+log_truncate_on_rotation = {{ postgres_log_truncate_on_rotation }}
+{% endif %}
+
+# Logging details (applies to both backends)
+log_line_prefix = '{{ postgres_log_line_prefix }}'
+log_timezone = '{{ postgres_log_timezone }}'
+{% if postgres_log_min_duration_statement >= 0 %}
+log_min_duration_statement = {{ postgres_log_min_duration_statement }}
+{% endif %}