Mistral Configuration Guide

Mistral configuration is needed for getting it work correctly either with real OpenStack environment or without OpenStack environment.

NOTE: The most of the following operations should performed in mistral directory.

1. Generate mistral.conf (if it does not already exist):

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

2. Edit file etc/mistral.conf.

3. If you are not using OpenStack, skip this item. Provide valid keystone auth properties:

   [keystone_authtoken]
   auth_uri = http://<Keystone-host>:5000/v3
   identity_uri = http://<Keystone-host:35357/
   auth_version = v3
   admin_user = <user>
   admin_password = <password>
   admin_tenant_name = <tenant>
   

4. If you want to configure SSL for Mistral API server, provide following options in config file:

   [api]
   enable_ssl_api = True
   
   [ssl]
   ca_file = <path-to-ca file>
   cert_file = <path-to-certificate file>
   key_file = <path-to-key file>
   

5. If you don’t use OpenStack or you want to disable authentication for the Mistral service, provide auth_enable = False in the config file:

   [pecan]
   auth_enable = False
   

6. If you are not using OpenStack, skip this item. Register Mistral service and Mistral endpoints on Keystone:

   $ MISTRAL_URL="http://[host]:[port]/v2"
   $ openstack service create workflow --name mistral --description 'OpenStack Workflow service'
   $ openstack endpoint create workflow --publicurl $MISTRAL_URL --adminurl $MISTRAL_URL --internalurl $MISTRAL_URL
   

7. Configure transport properties in the corresponding config section: for RabbitMQ it is oslo_messaging_rabbit:

   [oslo_messaging_rabbit]
   rabbit_userid = <user_id>
   rabbit_password = <password>
   rabbit_host = <host>
   

NOTE: Make sure that backend transport configuration is correct. Example for RabbitMQ:

[DEFAULT]
rpc_backend = rabbit

8. Configure database. SQLite can’t be used in production. Use MySQL or PostgreSQL instead. Here are the steps how to connect MySQL DB to Mistral:

Make sure you have installed mysql-server package on your Database machine (it can be your Mistral machine as well).

Install MySQL driver for python:

pip install mysql-python

Create the database and grant privileges:

mysql -u root -p

CREATE DATABASE mistral;
USE mistral
GRANT ALL ON mistral.* TO 'root':<password>@<database-host>;

Configure connection in Mistral config:

[database]
connection = mysql://<user>:<password>@<database-host>:3306/mistral

NOTE: If PostgreSQL is used, configure connection item as below:

connection = postgresql://<user>:<password>@<database-host>:5432/mistral

9. If you are not using OpenStack, skip this item. Update mistral/actions/openstack/mapping.json file which contains all allowed OpenStack actions, according to the specific client versions of OpenStack projects in your deployment. Please find more detailed information in tools/get_action_list.py script.

10. Configure Task affinity feature if needed. It is needed for distinguishing either single task executor or one task executor from group of task executors:

    [executor]
    

    host = my_favorite_executor

Then, this executor can be referred in DSL by:

...Workflow YAML...
my_task:
  ...
  target: my_favorite_executor
...Workflow YAML...

11. Configure role based access policies for Mistral endpoints (policy.json):

    [oslo_policy]
    policy_file = <path-of-policy.json file>
    

    Default policy.json file is in mistral/etc/. For more deatils see policy.json file.

12. After that try to run mistral engine and see it is running without any error:

    mistral-server --config-file <path-to-config> --server engine