From 012d3f3530f878e5143d58380f94d1f514baad04 Mon Sep 17 00:00:00 2001
From: Kevin Carter <kevin.carter@rackspace.com>
Date: Tue, 28 Mar 2017 23:37:26 -0500
Subject: [PATCH] Ensure the components are isolated from the system

This creates a specific slice which all OpenStack services will operate
from. By creating an independent slice these components will be governed
away from the system slice allowing us to better optimise resource
consumption.

See the following for more information on slices:

* https://www.freedesktop.org/software/systemd/man/systemd.slice.html

See for following for more information on resource controls:

* https://www.freedesktop.org/software/systemd/man/systemd.resource-control.html

Tools like ``systemd-cgtop`` and ``systemd-cgls`` will now give us
insight into specific processes, process groups, and resouce consumption
in ways that we've not had access to before. To enable some of this reporting
the accounting options have been added to the [Service] section of the unit
file.

Change-Id: Ic4edfa39b8ee42d0f6192b986e1c40c9c94488df
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>
---
 defaults/main.yml                                      |  5 +++++
 .../sahara-init-config-overrides-ffce7e419061c4da.yaml | 10 ++++++++++
 tasks/sahara_init_systemd.yml                          |  4 +++-
 templates/sahara-systemd-init.j2                       |  9 +++++++++
 4 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 releasenotes/notes/sahara-init-config-overrides-ffce7e419061c4da.yaml

diff --git a/defaults/main.yml b/defaults/main.yml
index 7c59114..d66e30c 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -163,14 +163,19 @@ sahara_pip_packages:
   - python-keystoneclient
   - warlock
 
+sahara_engine_init_overrides: {}
+sahara_api_init_overrides: {}
+
 ## Service Names
 sahara_services:
   sahara-api:
     group: sahara_api
     service_name: sahara-api
+    init_config_overrides: "{{ sahara_api_init_overrides }}"
   sahara-engine:
     group: sahara_engine
     service_name: sahara-engine
+    init_config_overrides: "{{ sahara_engine_init_overrides }}"
 
 # This variable is used by the repo_build process to determine
 # which host group to check for members of before building the
diff --git a/releasenotes/notes/sahara-init-config-overrides-ffce7e419061c4da.yaml b/releasenotes/notes/sahara-init-config-overrides-ffce7e419061c4da.yaml
new file mode 100644
index 0000000..8e63774
--- /dev/null
+++ b/releasenotes/notes/sahara-init-config-overrides-ffce7e419061c4da.yaml
@@ -0,0 +1,10 @@
+---
+features:
+  - New variables have been added to allow a deployer to customize
+    a sahara systemd unit file to their liking.
+  - The task dropping the sahara systemd unit files now uses the
+    ``config_template`` action plugin allowing deployers access to
+    customize the unit files as they see fit without having to
+    load extra options into the defaults and polute the generic
+    systemd unit file with jinja2 variables and conditionals.
+
diff --git a/tasks/sahara_init_systemd.yml b/tasks/sahara_init_systemd.yml
index 34863a4..d01cad5 100644
--- a/tasks/sahara_init_systemd.yml
+++ b/tasks/sahara_init_systemd.yml
@@ -54,12 +54,14 @@
   when: inventory_hostname in groups[item.value.group]
 
 - name: Place the systemd init script
-  template:
+  config_template:
     src: "sahara-systemd-init.j2"
     dest: "/etc/systemd/system/{{ item.value.service_name }}.service"
     mode: "0644"
     owner: "root"
     group: "root"
+    config_overrides: "{{ item.value.init_config_overrides }}"
+    config_type: "ini"
   with_dict: "{{ sahara_services }}"
   when: inventory_hostname in groups[item.value.group]
   notify:
diff --git a/templates/sahara-systemd-init.j2 b/templates/sahara-systemd-init.j2
index 64ea8a7..3758ac7 100644
--- a/templates/sahara-systemd-init.j2
+++ b/templates/sahara-systemd-init.j2
@@ -21,5 +21,14 @@ TimeoutSec=300
 Restart=on-failure
 RestartSec=150
 
+# This creates a specific slice which all services will operate from
+#  The accounting options give us the ability to see resource usage through
+#  the `systemd-cgtop` command.
+Slice=sahara.slice
+CPUAccounting=true
+BlockIOAccounting=true
+MemoryAccounting=false
+TasksAccounting=true
+
 [Install]
 WantedBy=multi-user.target