update glusterfs role to include deployment of gluster_exporter for prometheus

roles/glusterfs/tasks/prometheus_exporter.yml

@@ -0,0 +1,31 @@
+---
+# tasks to install prometheus gluster_exporter
+# https://github.com/ofesseler/gluster_exporter
+
+# install packages
+- name: Update apt cache.
+  apt: update_cache=yes cache_valid_time=86400
+
+- name: Install gluster_exporter dependencies.
+  apt: "name={{ item }} state=installed"
+  with_items:
+    - golang-go
+
+- name: make golang workspace
+  file:
+    path: /opt/golang
+    state: directory
+    mode: 0775
+
+- name: install gluster_exporter
+  shell: GOPATH=/opt/golang go get github.com/ofesseler/gluster_exporter
+
+- name: add gluster_exporter to startup
+  lineinfile:
+    dest: /etc/rc.local
+    regexp: '/opt/golang/bin/gluster_exporter'
+    line: 'nohup /opt/golang/bin/gluster_exporter --profile &'
+    insertbefore: "^exit 0"
+
+- name: start gluster_exporter
+  shell: nohup /opt/golang/bin/gluster_exporter --profile &