redis-server: Allow configuration

redis-server/defaults/main.yml

+---
+
+redis_bind: "127.0.0.1 ::1"
+# Set to "0" to disable TCP
+redis_port: "6379"
+redis_unixsocket: false
+redis_unixsocketperm: "770"

redis-server/files/override.conf

+[Service]
+Type=notify

redis-server/handlers/main.yml

+---
+
+- name: Reload systemd
+  systemd:
+    daemon-reload: true
+
+- name: Restart redis-server
+  systemd:
+    unit: redis-server.service
+    state: restarted

redis-server/tasks/main.yml

 ---
 
-- name: ensure we have redis installed
+- name: Install redis-server
   apt:
     name: redis-server
     state: present
+
+- name: Create systemd unit override directory
+  file:
+    path: /etc/systemd/system/redis-server.service.d
+    state: directory
+
+- name: Configure redis-server systemd options
+  copy:
+    src: override.conf
+    dest: /etc/systemd/system/redis-server.service.d/override.conf
+  notify:
+    - Reload systemd
+    - Restart redis-server
+
+- name: Configure redis-server
+  template:
+    src: redis.conf.j2
+    dest: /etc/redis/redis.conf
+    owner: redis
+    group: redis
+    mode: '0640'
+  notify:
+    - Restart redis-server
+
+- name: Enable and start redis-server
+  systemd:
+    unit: redis-server.service
+    enabled: true
+    state: started