Mongo on 16.04 fixes

We need to install a mongod.service under systemd.
This requires templating a file and then enabling it for systemd.

playbooks/roles/mongo_2_6/tasks/main.yml

@@ -118,6 +118,27 @@
     - install
     - install:configuration
 
+- name: Add mongod systemd configuration on 16.04
+  template:
+    src:  "etc/systemd/system/mongod.service.j2"
+    dest: "/etc/systemd/system/mongod.service"
+  notify:
+    - restart mongo
+  when: ansible_distribution_release == 'xenial'
+  tags:
+    - install
+    - install:configuration
+
+- name: enable mongod systemd unit on 16.04
+  systemd_2_2:
+    name: mongod
+    enabled: yes
+    daemon_reload: yes
+  when: ansible_distribution_release == 'xenial'
+  tags:
+    - install
+    - install:configuration
+
 - name: Start mongo service
   service:
     name: mongod

playbooks/roles/mongo_2_6/templates/etc/systemd/system/mongod.service.j2

+[Unit]
+Description=High-performance, schema-free document-oriented database
+After=network.target
+Documentation=https://docs.mongodb.org/manual
+
+[Service]
+User=mongodb
+ExecStart=/usr/bin/mongod --quiet --config /etc/mongod.conf
+Group=mongodb
+
+# Recommended limits for for mongod as specified in
+# http://docs.mongodb.org/manual/reference/ulimit/#recommended-settings
+# These may need tuning for dev instances.
+# file size
+LimitFSIZE=infinity
+# cpu time
+LimitCPU=infinity
+# virtual memory size
+LimitAS=infinity
+# open files
+LimitNOFILE=64000
+# processes/threads
+LimitNPROC=64000
+# total threads (user+kernel)
+TasksMax=infinity
+TasksAccounting=false
+
+[Install]
+WantedBy=multi-user.target