Ensure that log dir exists

because Postgres does not create it by itself
if you change it from the default value

README.md

@@ -47,8 +47,10 @@ Control the state of the postgresql service and whether it should start at boot
     postgresql_global_config_options:
       - option: unix_socket_directories
         value: '{{ postgresql_unix_socket_directories | join(",") }}'
+      - option: log_directory
+        value: 'log'
 
-Global configuration options that will be set in `postgresql.conf`. Note that for RHEL/CentOS 6 (or very old versions of PostgreSQL), you need to at least override this variable and set the `option` to `unix_socket_directory`.
+Global configuration options that will be set in `postgresql.conf`. Note that if you override 'log_directory' with another, absolute path, this role will create it for you. 
 
     postgresql_hba_entries:
       - { type: local, database: all, user: postgres, auth_method: peer }

defaults/main.yml

@@ -23,6 +23,8 @@ postgresql_service_enabled: true
 postgresql_global_config_options:
   - option: unix_socket_directories
     value: '{{ postgresql_unix_socket_directories | join(",") }}'
+  - option: log_directory
+    value: 'log'
 
 # Host based authentication (hba) entries to be added to the pg_hba.conf. This
 # variable's defaults reflect the defaults that come with a fresh installation.

tasks/initialize.yml

@@ -14,6 +14,14 @@
     state: directory
     mode: 0700
 
+- name: Ensure PostgreSQL log directory exists.
+  file:
+    path: "{{ postgresql_effective_log_dir }}"
+    owner: "{{ postgresql_user }}"
+    group: "{{ postgresql_group }}"
+    state: directory
+    mode: 0700
+
 - name: Check if PostgreSQL database is initialized.
   stat:
     path: "{{ postgresql_data_dir }}/PG_VERSION"

tasks/variables.yml

@@ -49,3 +49,21 @@
     postgresql_unix_socket_directories_mode: >-
       {{ __postgresql_unix_socket_directories_mode | default('02775') }}
   when: postgresql_unix_socket_directories_mode is not defined
+
+- name: Define postgresql_log_dir.
+  set_fact:
+    postgresql_log_dir: "{{ (postgresql_global_config_options | items2dict(key_name='option', value_name='value')).log_directory }}"
+
+- name: Define postgresql_log_dir_is_absolute.
+  set_fact:
+    postgresql_log_dir_is_absolute: '{{ postgresql_log_dir | regex_search("^/.*") != "" }}'
+
+- name: Define postgresql_effective_log_dir, if postgresql_log_dir_is_absolute
+  set_fact:
+    postgresql_effective_log_dir: '{{ postgresql_log_dir }}'
+  when: postgresql_log_dir_is_absolute
+
+- name: Define postgresql_effective_log_dir, if not postgresql_log_dir_is_absolute
+  set_fact:
+    postgresql_effective_log_dir: '{{ postgresql_data_dir }}/{{ postgresql_log_dir }}'
+  when: not postgresql_log_dir_is_absolute