mistral 5.0.0.0b1

Mistral Project

========================
Team and repository tags
========================

.. image:: http://governance.openstack.org/badges/mistral.svg
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Mistral
=======

Workflow Service for OpenStack cloud. This project aims to provide a mechanism
to define tasks and workflows without writing code, manage and execute them in
the cloud environment.

Installation
~~~~~~~~~~~~

The following are the steps to install Mistral on debian-based systems.

To install Mistral, you have to install the following prerequisites:

$ apt-get install python-dev python-setuptools libffi-dev \
libxslt1-dev libxml2-dev libyaml-dev libssl-dev

**Mistral can be used without authentication at all or it can work with
OpenStack.**

In case of OpenStack, it works **only with Keystone v3**, make sure **Keystone
v3** is installed.


Install Mistral
---------------

First of all, clone the repo and go to the repo directory::

$ git clone https://git.openstack.org/openstack/mistral.git
$ cd mistral


**Devstack installation**

Information about how to install Mistral with devstack can be found
`here <http://docs.openstack.org/developer/mistral/developer/devstack.html>`_.

Configuring Mistral
~~~~~~~~~~~~~~~~~~~

Mistral configuration is needed for getting it work correctly with and without
an OpenStack environment.

#. Install and configure a database which can be *MySQL* or *PostgreSQL*
(**SQLite can't be used in production.**). Here are the steps to connect
Mistral to a *MySQL* database.

* Make sure you have installed ``mysql-server`` package on your Mistral
machine.
* Install *MySQL driver* for python::

$ pip install mysql-python

or, if you work in virtualenv, run::

$ tox -evenv -- pip install mysql-python

NOTE: If you're using Python 3 then you need to install ``mysqlclient``
instead of ``mysql-python``.

* Create the database and grant privileges::

$ mysql -u root -p
CREATE DATABASE mistral;
USE mistral
GRANT ALL ON mistral.* TO 'root'@'localhost';

#. Generate ``mistral.conf`` file::

$ oslo-config-generator \
--config-file tools/config/config-generator.mistral.conf \
--output-file etc/mistral.conf.sample

#. Copy service configuration files::

$ sudo mkdir /etc/mistral
$ sudo chown `whoami` /etc/mistral
$ cp etc/event_definitionas.yml.sample /etc/mistral/event_definitions.yml
$ cp etc/logging.conf.sample /etc/mistral/logging.conf
$ cp etc/policy.json /etc/mistral/policy.json
$ cp etc/wf_trace_logging.conf.sample /etc/mistral/wf_trace_logging.conf
$ cp etc/mistral.conf.sample /etc/mistral/mistral.conf

#. Edit file ``/etc/mistral/mistral.conf`` according to your setup. Pay attention to
the following sections and options::

[oslo_messaging_rabbit]
rabbit_host = <RABBIT_HOST>
rabbit_userid = <RABBIT_USERID>
rabbit_password = <RABBIT_PASSWORD>

[database]
# Use the following line if *PostgreSQL* is used
# connection = postgresql://<DB_USER>:<DB_PASSWORD>@localhost:5432/mistral
connection = mysql://<DB_USER>:<DB_PASSWORD>@localhost:3306/mistral

#. If you are not using OpenStack, add the following entry to the
``/etc/mistral/mistral.conf`` file and **skip the following steps**::

[pecan]
auth_enable = False

#. Provide valid keystone auth properties::

[keystone_authtoken]
auth_uri = http://<Keystone-host>/identity_v2_admin/v3
identity_uri = http://<Keystone-host/identity_v2_admin
auth_version = v3
admin_user = <user>
admin_password = <password>
admin_tenant_name = <tenant>

#. Register Mistral service and Mistral endpoints on Keystone::

$ MISTRAL_URL="http://[host]:[port]/v2"
$ openstack service create --name mistral workflowv2
$ openstack endpoint create mistral public $MISTRAL_URL
$ openstack endpoint create mistral internal $MISTRAL_URL
$ openstack endpoint create mistral admin $MISTRAL_URL

#. Update the ``mistral/actions/openstack/mapping.json`` file which contains
all available OpenStack actions, according to the specific client versions
of OpenStack projects in your deployment. Please find more detailed
information in the ``tools/get_action_list.py`` script.

Before the First Run
--------------------

After local installation you will find the commands ``mistral-server`` and
``mistral-db-manage`` available in your environment. The ``mistral-db-manage``
command can be used for migrating database schema versions. If Mistral is not
installed in system then this script can be found at
``mistral/db/sqlalchemy/migration/cli.py``, it can be executed using Python
command line.

To update the database schema to the latest revision, type::

$ mistral-db-manage --config-file <path_to_config> upgrade head

To populate the database with standard actions and workflows, type::
$ mistral-db-manage --config-file <path_to_config> populate

For more detailed information about ``mistral-db-manage`` script please check
file ``mistral/db/sqlalchemy/migration/alembic_migrations/README.md``.

Running Mistral API server
--------------------------

To run Mistral API server::

$ tox -evenv -- python mistral/cmd/launch.py \
--server api --config-file <path_to_config>

Running Mistral Engines
-----------------------

To run Mistral Engine::

$ tox -evenv -- python mistral/cmd/launch.py \
--server engine --config-file <path_to_config>

Running Mistral Task Executors
------------------------------

To run Mistral Task Executor instance::

$ tox -evenv -- python mistral/cmd/launch.py \
--server executor --config-file <path_to_config>

Note that at least one Engine instance and one Executor instance should be
running in order for workflow tasks to be processed by Mistral.

If you want to run some tasks on specific executor, the *task affinity* feature
can be used to send these tasks directly to a specific executor. You can edit
the following property in your mistral configuration file for this purpose::

[executor]
host = my_favorite_executor

After changing this option, you will need to start (restart) the executor. Use
the ``target`` property of a task to specify the executor::

... Workflow YAML ...
task1:
...
target: my_favorite_executor
... Workflow YAML ...

Running Multiple Mistral Servers Under the Same Process
-------------------------------------------------------

To run more than one server (API, Engine, or Task Executor) on the same
process::

$ tox -evenv -- python mistral/cmd/launch.py \
--server api,engine --config-file <path_to_config>

The value for the ``--server`` option can be a comma-delimited list. The valid
options are ``all`` (which is the default if not specified) or any combination
of ``api``, ``engine``, and ``executor``.

It's important to note that the ``fake`` transport for the ``rpc_backend``
defined in the configuration file should only be used if ``all`` Mistral
servers are launched on the same process. Otherwise, messages do not get
delivered because the ``fake`` transport is using an in-process queue.

Project Resources
-----------------

* `Mistral Official Documentation <http://docs.openstack.org/developer/mistral/>`_

* Project status, bugs, and blueprints are tracked on
`Launchpad <https://launchpad.net/mistral/>`_

* Additional resources are linked from the project
`Wiki <https://wiki.openstack.org/wiki/Mistral/>`_ page

* Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0