Add heka custom config to define user's log pipline

Kolla's default heka pipline may not satisfy user's requirements,
for example, sending openstack log to outer log analyze system.
So it is necessary to add heka custom configuration for define
user's encoders, outputs and other plugins.

Change-Id: I48bd8d7e0afbc2d023c49c83041f87a04970bbb6
Closes-Bug: #1611164

ansible/roles/common/tasks/config.yml

@@ -48,6 +48,16 @@
     - { name: "swift-proxy-server", src: "swift", enabled: "{{ enable_swift }}" }
     - { name: "swift-rsyncd", src: "swift", enabled: "{{ enable_swift }}" }
 
+- name: Heka custom config file exists
+  stat: "path={{ node_custom_config }}/heka/heka-custom.toml"
+  register: heka_custom_stat_result
+
+- name: Copying over heka custom config file
+  template:
+    src: "{{ node_custom_config }}/heka/heka-custom.toml"
+    dest: "{{ node_config_directory }}/heka/heka-custom.toml"
+  when: heka_custom_stat_result.stat.exists == true
+
 - name: Copying over cron logrotate config files
   template:
     src: "cron-logrotate-{{ item }}.conf.j2"

ansible/roles/common/templates/heka.json.j2

@@ -15,6 +15,13 @@
             "owner": "heka",
             "perm": "0600"
         },
+        {
+            "source": "{{ container_config_directory }}/heka-custom.toml",
+            "dest": "/etc/heka/heka-custom.toml",
+            "owner": "heka",
+            "perm": "0600",
+            "optional": true
+        },
         {
             "source": "{{ container_config_directory }}/heka-haproxy.toml",
             "dest": "/etc/heka/heka-haproxy.toml",