fix(database): more resilient postgres install

- Classified tasks with conditionals
- Added separate plays for installing/configuring
postgresql and for administrating the pleroma
database.
- Added a handler to restart postgres when its
configuration changes.
- Removed the task that automatically restarts postgres.
This was replaced by a task to enable the service only.

Part of dananglin/pleroma-ansible-playbook#17

playbook.yml

@@ -1,12 +1,12 @@
 ---
-- name: Initialising the playbook.
+- name: Gathering user's configuration.
   hosts: all
   roles:
   - init
   tags:
   - always
 
-- name: Setting up the Pleroma database.
+- name: Installing and configuring the PostgreSQL engine.
   hosts: pleroma_database
   become: yes
   become_method: sudo
@@ -14,6 +14,19 @@
   - pleroma-database
   tags:
   - pleroma-database
+  vars:
+    pleroma_database_installation: True
+
+- name: Performing database administration.
+  hosts: pleroma_database
+  become: yes
+  become_method: sudo
+  roles:
+  - pleroma-database
+  tags:
+  - pleroma-database
+  vars:
+    pleroma_database_administration: True
 
 - name: Setting up Pleroma.
   hosts: pleroma_main

roles/pleroma-database/tasks/main.yml

@@ -3,6 +3,7 @@
   apk:
     name: "{{ pleroma_postgres_packages }}"
     state: present
+  when: pleroma_database_installation | default(False)
 
 - name: Postgres -- Ensure that the database is initialised.
   command:
@@ -10,6 +11,7 @@
     - /etc/init.d/postgresql
     - setup
     creates: /var/lib/postgresql/11/data/postgresql.conf
+  when: pleroma_database_installation | default(False)
 
 - name: Postgres -- Ensuring that the additional directories exist.
   file:
@@ -21,6 +23,7 @@
   loop:
   - "{{ pleroma_postgres_log_dir }}"
   - "{{ pleroma_postgres_confd }}"
+  when: pleroma_database_installation | default(False)
 
 - name: Postgres -- Ensuring that PostgreSQL is configured.
   template:
@@ -32,6 +35,8 @@
   loop:
   - { src: etc_postgresql_pg_hba.conf.j2, dest: "{{ pleroma_postgres_base_conf }}/pg_hba.conf" }
   - { src: etc_postgresql_confd_postgresql_override.conf, dest: "{{ pleroma_postgres_confd }}/postgresql_override.conf" }
+  when: pleroma_database_installation | default(False)
+  notify: "restart postgres"
 
 - name: Postgres -- Ensuring that the symlink to the override config is present.
   file:
@@ -41,6 +46,8 @@
     path: "{{ pleroma_postgres_confd_symlink }}"
     src: "{{ pleroma_postgres_confd }}"
     state: link
+  when: pleroma_database_installation | default(False)
+  notify: "restart postgres"
 
 - name: Postgres -- Ensuring that the override config is included in the main config.
   lineinfile:
@@ -51,12 +58,14 @@
     path: "{{ pleroma_postgres_base_conf }}/postgresql.conf"
     regexp: ^.*include\s=\s'.*'.*$
     state: present
+  when: pleroma_database_installation | default(False)
+  notify: "restart postgres"
 
 - name: Postgres -- Ensuring that PostgreSQL is enabled and started.
   service:
     name: postgresql
     enabled: yes
-    state: restarted
+  when: pleroma_database_installation | default(False)
 
 - name: Postgres -- Ensuring that Postgres is available before continuing.
   wait_for:
@@ -65,6 +74,7 @@
     host: localhost
     port: 5432
     state: started
+  when: pleroma_database_administration | default(False)
 
 - name: Postgres -- Ensuring that the database user {{ pleroma.config.db.user }} exists.
   become_user: postgres
@@ -77,6 +87,7 @@
     state: present
   vars:
     ansible_ssh_pipelining: true
+  when: pleroma_database_administration | default(False)
 
 - name: Postgres -- Ensuring that the database {{ pleroma.config.db.name }} exists.
   become_user: postgres
@@ -89,6 +100,7 @@
     state: present
   vars:
     ansible_ssh_pipelining: true
+  when: pleroma_database_administration | default(False)
 
 - name: Postgres -- Ensuring the PostgreSQL extensions is added to the database.
   become_user: postgres
@@ -103,3 +115,4 @@
   - uuid-ossp
   vars:
     ansible_ssh_pipelining: true
+  when: pleroma_database_administration | default(False)