r/mosquitto: Support persistence

Mosquitto can save retained messages, persistent clients, etc. to the
filesystem and restore them at startup.  This allows state to be
maintained even after the process restarts.

roles/mosquitto/tasks/main.yml

@@ -5,6 +5,17 @@
   tags:
   - install
 
+- name: ensure mosquitto persistence directory exists
+  file:
+    path: '{{ mosquitto_persistence_location }}'
+    mode: u=rwx,go=
+    owner: mosquitto
+    group: mosquitto
+    state: directory
+  when: mosquitto_persistence_location|d(none) is not none
+  tags:
+  - datadir
+
 - name: ensure mosquitto certificate is installed
   copy:
     src: certs/mosquitto/{{ inventory_hostname }}.cer
@@ -15,6 +26,8 @@
   notify:
   - restart mosquitto
   when: mosquitto_certfile is defined
+  tags:
+  - cert
 - name: ensure mosquitto private key is installed
   copy:
     src: certs/mosquitto/{{ inventory_hostname }}.key
@@ -26,6 +39,8 @@
   notify:
   - restart mosquitto
   when: mosquitto_keyfile is defined
+  tags:
+  - cert
 
 - name: ensure mosquitto is configured
   template:
@@ -34,6 +49,8 @@
     mode: '0644'
   notify:
   - restart mosquitto
+  tags:
+  - mosquitto-config
 
 - meta: flush_handlers
 
@@ -41,7 +58,11 @@
   service:
     name: mosquitto
     enabled: true
+  tags:
+  - service
 - name: ensure mosquitto is running
   service:
     name: mosquitto
     state: started
+  tags:
+  - service

roles/mosquitto/templates/mosquitto.conf.j2

@@ -405,31 +405,51 @@ listener {{ listener.port }} {{ listener.address|d('') }}
 # autosave_on_changes.
 # Note that writing of the persistence database can be forced by
 # sending mosquitto a SIGUSR1 signal.
+{% if mosquitto_autosave_interval|d(none) is not none %}
+autosave_interval {{ mosquitto_autosave_interval }}
+{% else %}
 #autosave_interval 1800
+{% endif %}
 
 # If true, mosquitto will count the number of subscription changes, retained
 # messages received and queued messages and if the total exceeds
 # autosave_interval then the in-memory database will be saved to disk.
 # If false, mosquitto will save the in-memory database to disk by treating
 # autosave_interval as a time in seconds.
+{% if mosquitto_autosave_on_changes|d(none) is not none %}
+autosave_on_changes {{ mosquitto_autosave_on_changes|bool|string|lower }}
+{% else %}
 #autosave_on_changes false
+{% endif %}
 
 # Save persistent message data to disk (true/false).
 # This saves information about all messages, including
 # subscriptions, currently in-flight messages and retained
 # messages.
 # retained_persistence is a synonym for this option.
+{% if mosquitto_persistence|d(none) is not none %}
+persistence {{ mosquitto_persistence|bool|string|lower }}
+{% else %}
 #persistence false
+{% endif %}
 
 # The filename to use for the persistent database, not including
 # the path.
+{% if mosquitto_persistence_file|d(none) is not none %}
+persistence_file {{ mosquitto_persistence_file }}
+{% else %}
 #persistence_file mosquitto.db
+{% endif %}
 
 # Location for persistent database.
 # Default is an empty string (current directory).
 # Set to e.g. /var/lib/mosquitto if running as a proper service on Linux or
 # similar.
+{% if mosquitto_persistence_location|d(none) is not none %}
+persistence_location {{ mosquitto_persistence_location }}
+{% else %}
 #persistence_location
+{% endif %}
 
 
 # =================================================================