Adding Mistral Workflow Service to OpenStack

Provide a simple YAML-based language to write workflows  (tasks and
transitions), and a service that allows to upload them, modify, run them at at
scale and in a highly available manner, manage and monitor workflow executions
and states of individual tasks.

The code base has existed for 1 year and 4 months in the stackforge code
namespace.

Mistral community has been consistently growing from cycle to cycle and now
includes more than 10 contributors from Mirantis, StackStorm, Huawei, HP,
Symantec, and Ericsson.

We will hold elections for our PTL, currently Renat Akhmerov, on a regular basis
according to standard OpenStack community practices. We hold weekly team
meetings on IRC where we discuss Mistral design, blueprints, issues, roadblocks
and roadmap. We also use openstack-dev@lists.openstack.org mailing list for all
offline discussions related to new ideas, design and implementation. Blueprints
and bugs are tracked using Launchpad according to OpenStack rules. The gerrit
review board rules are strictly followed. Mistral is integrated with devstack,
and runs tempus functional tests as gate tests. Functional tests are integrated
with devstack, tempest, and rally and run as gates.

Mistral is implemented using libraries and technologies adopted by OpenStack
community such as SqlAlchemy for object persistence, oslo.messaging for RPC
communications, and others.

Mistral is also integrated with other OpenStack services. It has full dynamic
support for OpenStack actions - Keystone, Nova, Glance, Heat, Cinder, Neutron,
so any openstack operations can be used in workflows. Murano project has the
ability to call Mistral workflows from Murano PL. There are also two patches on
review that add Mistral related resources into Heat (workflows and cron
triggers). There is interest from other projects to using Mistral, expressed
from Congress, Trove, Solum, Barbican, Heat, and Keystone.

Change-Id: I5d0e877903c3f55ce2330e301b27da9435f677c5

reference/projects.yaml

@@ -886,3 +886,18 @@ Rally:
   url: https://wiki.openstack.org/wiki/Rally
   projects:
     - repo: openstack/rally
+
+Mistral:
+  ptl: Renat Akhmerov (rakhmerov)
+  service: Workflow Service
+  mission: >
+    Provide a simple YAML-based language to write workflows (tasks and transition rules)
+    and a service that allows to upload them, modify, run them at scale and in a highly
+    available manner, manage and monitor workflow execution state and state of individual tasks.
+  url: https://wiki.openstack.org/wiki/Mistral
+  projects:
+    - repo: openstack/mistral
+    - repo: openstack/mistral-dashboard
+    - repo: openstack/mistral-extra
+    - repo: openstack/python-mistralclient
+