From 4c743ded8ec67ab15eec8dfa950c9cda5125b2dd Mon Sep 17 00:00:00 2001
From: Gergely Csatari <gergely.csatari@nokia.com>
Date: Mon, 29 Apr 2019 01:50:06 +0200
Subject: [PATCH] Adding sequence diagram to Architecture

A high level sequence diagram is added to the Architecture page to
illustrate the workflow between Fenix and the app manager.

Change-Id: I51220cdc64eb34d0f60c5425c654efae76f9f624
Signed-off-by: Gergely Csatari <gergely.csatari@nokia.com>
---
 doc/requirements.txt             |  1 +
 doc/source/conf.py               |  5 +++++
 doc/source/user/architecture.rst | 27 +++++++++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/doc/requirements.txt b/doc/requirements.txt
index 95b6568..03105b0 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,5 +1,6 @@
 sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
 openstackdocstheme>=1.18.1  # Apache-2.0
 os-api-ref>=1.6.0 # Apache-2.0
+sphinxcontrib-seqdiag>=0.8.4  # BSD
 # releasenotes
 reno>=2.5.0 # Apache-2.0
diff --git a/doc/source/conf.py b/doc/source/conf.py
index a9b9a6f..0f2522f 100755
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -24,6 +24,7 @@ extensions = [
     'sphinx.ext.autodoc',
     'openstackdocstheme',
     'os_api_ref',
+    'sphinxcontrib.seqdiag',
     #'sphinx.ext.intersphinx',
 ]
 
@@ -31,6 +32,10 @@ extensions = [
 # text edit cycles.
 # execute "export SPHINX_DEBUG=1" in your terminal to disable
 
+# sphinxcontrib.seqdiag options
+seqdiag_antialias = True
+seqdiag_html_image_format = 'SVG'
+
 # The suffix of source filenames.
 source_suffix = '.rst'
 
diff --git a/doc/source/user/architecture.rst b/doc/source/user/architecture.rst
index c72ec01..5eaefb5 100644
--- a/doc/source/user/architecture.rst
+++ b/doc/source/user/architecture.rst
@@ -99,3 +99,30 @@ back in normal use. This might be important for enabling/disabling self-healing
 or billing. Notification can also be used to indicate when a host is added or
 removed.
 
+High level sequence diagram
+===========================
+
+.. seqdiag::
+
+    seqdiag {
+        activation = none;
+        infra-admin  -> fenix [label = "Maintenance session for hosts", note="Start the maintenance process"];
+        fenix -> app-manager [label = "MAINTENANCE"];
+        app-manager -> fenix [label = "ACK_MAINTENANCE"];
+        fenix --> app-manager [label = "IN_SCALE", note="Optional down scale"]
+        app-manager --> fenix [label = "ACK_IN_SCALE"]
+        fenix --> app-manager [label = "PREPARE_MAINTENANCE", note="If there is not empty host Fenix makes one"]
+        app-manager --> fenix [label = "ACK_PREPARE_MAINTENANCE"]
+        fenix --> app-manager [label = "ADMIN_ACTION_DONE"]
+        === Repeated for every compute ===
+        fenix -> app-manager [label = "PLANNED_MAINTENANCE", note="If VM-s are on the host. Migrate or Live migrate"]
+        app-manager -> fenix [label = "ACK_PLANNED_MAINTENANCE"]
+        fenix --> app-manager [label = "ADMIN_ACTION_DONE"]
+        fenix --> app-manager [label = "IN_MAINTENANCE"]
+        ... Actual maintenance happens here ...
+        fenix --> app-manager [label = "MAINTENANCE_COMPLETE"]
+        === --- ===
+        fenix --> app-manager [label = "MAINTENANCE_COMPLETE", note="Maintenance is done"]
+        app-manager --> fenix [label = "ACK_MAINTENANCE_COMPLETE", note="Up scale"]
+
+    }