Mistral Installation Guide

Mistral Installation Guide

Prerequisites

It is necessary to install some specific system libs for installing Mistral. They can be installed on most popular operating system using their package manager (for Ubuntu - apt, for Fedora - dnf, CentOS - yum, for Mac OS - brew or macports). The list of needed packages is shown below:

  1. python-dev

  2. python-setuptools

  3. python-pip

  4. libffi-dev

  5. libxslt1-dev (or libxslt-dev)

  6. libxml2-dev

  7. libyaml-dev

  8. libssl-dev

In case of Ubuntu, just run:

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

NOTE: Mistral can be used without authentication at all or it can work with OpenStack. In case of OpenStack, it works only on Keystone v3, make sure Keystone v3 is installed.

Installation

NOTE: If it is needed to install Mistral using devstack, please refer to Mistral Devstack Installation

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

$ git clone https://github.com/openstack/mistral.git
$ cd mistral

Install tox:

$ pip install tox

Generate config:

$ tox -egenconfig

Configure Mistral as needed. The configuration file is located in etc/mistral.conf.sample. You will need to modify the configuration options and then copy it into /etc/mistral/mistral.conf. For details see Mistral Configuration Guide

Virtualenv installation:

$ tox

This will install necessary virtual environments and run all the project tests. Installing virtual environments may take significant time (~10-15 mins).

Local installation:

$ pip install -e .

or:

$ pip install -r requirements.txt
$ python setup.py install

NOTE: Differences pip install -e and setup.py install. pip install -e works very similarly to setup.py install or the EasyInstall tool, except that it doesn’t actually install anything. Instead, it creates a special .egg-link file in the deployment directory, that links to your project’s source code.

Before the first run

After installation you will see mistral-server and mistral-db-manage commands in your environment, either in system or virtual environment.

NOTE: In case of using virtualenv, all Mistral related commands available via tox -evenv –. For example, mistral-server is available via tox -evenv – mistral-server.

mistral-db-manage command can be used for migrations.

For updating the database to the latest revision type:

$ mistral-db-manage --config-file <path-to-mistral.conf> upgrade head

Before starting Mistral server, run mistral-db-manage populate command. It prepares the database with standard actions and workflows which Mistral will provide for all users.:

$ mistral-db-manage --config-file <path-to-mistral.conf> populate

For more detailed information about mistral-db-manage script please see Mistral Upgrade Guide.

NOTE: For users who want a dry run with SQLite database backend(not used in production), mistral-db-manage is not recommended for database initialization because of SQLite limitations. Please use sync_db script described below instead for database initialization.

If you use virtualenv:

$ tools/sync_db.sh --config-file <path-to-mistral.conf>

Or run sync_db directly:

$ python tools/sync_db.py --config-file <path-to-mistral.conf>

Running Mistral API server

To run Mistral API server perform the following command in a shell:

$ mistral-server --server api --config-file <path-to-mistral.conf>

Running Mistral Engines

To run Mistral Engine perform the following command in a shell:

$ mistral-server --server engine --config-file <path-to-mistral.conf>

Running Mistral Task Executors

To run Mistral Task Executor instance perform the following command in a shell:

$ mistral-server --server executor --config-file <path-to-mistral.conf>

Running Mistral Notifier

To run Mistral Notifier perform the following command in a shell:

$ mistral-server --server notifier -- config-file <path-to-mistral.conf>

Note that at least one Engine instance and one Executor instance should be running so that workflow tasks are processed by Mistral.

Running Multiple Mistral Servers Under the Same Process

To run more than one server (API, Engine, or Task Executor) on the same process, perform the following command in a shell:

$ mistral-server --server api,engine --config-file <path-to-mistral.conf>

The –server command line option can be a comma delimited list. The valid options are “all” (by default if not specified) or any combination of “api”, “engine”, “notifier” and “executor”. It’s important to note that the “fake” transport for the rpc_backend defined in the config file should only be used if “all” the Mistral servers are launched on the same process. Otherwise, messages do not get delivered if the Mistral servers are launched on different processes because the “fake” transport is using an in process queue.

Running Mistral By Systemd

  1. Create an upstart config, it could be named as /etc/systemd/system/mistral-api.service:

    [Unit]
    Description = Openstack Workflow Service API
    
    [Service]
    ExecStart = /usr/bin/mistral-server --server api --config-file /etc/mistral/mistral.conf
    User = mistral
    
    [Install]
    WantedBy = multi-user.target
    
  2. Enable and start mistral-api:

    # systemctl enable mistral-api
    # systemctl start mistral-api
    
  3. Verify that mistral-api services are running:

    # systemctl status mistral-api
    
  4. Create an upstart config, it could be named as /etc/systemd/system/mistral-engine.service:

    [Unit]
    Description = Openstack Workflow Service Engine
    
    [Service]
    ExecStart = /usr/bin/mistral-server --server engine --config-file /etc/mistral/mistral.conf
    User = mistral
    
    [Install]
    WantedBy = multi-user.target
    
  5. Enable and start mistral-engine:

    # systemctl enable mistral-engine
    # systemctl start mistral-engine
    
  6. Verify that mistral-engine services are running:

    # systemctl status mistral-engine
    
  7. Create an upstart config, it could be named as /etc/systemd/system/mistral-notifier.service:

    [Unit]
    Description = Openstack Workflow Service Notifier
    
    [Service]
    ExecStart = /usr/bin/mistral-server --server notifier --config-file /etc/mistral/mistral.conf
    User = mistral
    
    [Install]
    WantedBy = multi-user.target
    
  8. Enable and start mistral-notifier:

    # systemctl enable mistral-notifier
    # systemctl start mistral-notifier
    
  9. Verify that mistral-notifier services are running:

    # systemctl status mistral-notifier
    
  10. Create an upstart config, it could be named as /etc/systemd/system/mistral-executor.service:

    [Unit]
    Description = Openstack Workflow Service Executor
    
    [Service]
    ExecStart = /usr/bin/mistral-server --server executor --config-file /etc/mistral/mistral.conf
    User = mistral
    
    [Install]
    WantedBy = multi-user.target
    
  11. Enable and start mistral-executor:

    # systemctl enable mistral-executor
    # systemctl start mistral-executor
    
  12. Verify that mistral-executor services are running:

    # systemctl status mistral-executor
    

Mistral And Docker

Docker containers provide an easy way to quickly deploy independent or networked Mistral instances in seconds. This guide describes the process to launch an all-in-one Mistral container.

Docker Installation

The following links contain instructions to install latest Docker software:

Build the Mistral Image Manually

Execute the following command from the repository top-level directory:

docker build -t mistral -f tools/docker/Dockerfile .

The Mistral Docker image has one build parameter:

Name

Default value

Description

BUILD_TEST_DEPENDENCIES

false

If the BUILD_TEST_DEPENDENCIES equals true, the Mistral test dependencies will be installed inside the Docker image

Running Mistral using Docker Compose

To launch Mistral in the single node configuration:

docker-compose -f tools/docker/docker-compose/infrastructure.yaml \
             -f tools/docker/docker-compose/mistral-single-node.yaml \
             -p mistral up -d

To launch Mistral in the multi node configuration:

docker-compose -f tools/docker/docker-compose/infrastructure.yaml \
             -f tools/docker/docker-compose/mistral-multi-node.yaml \
             -p mistral up -d

The infrastructure docker-compose file contains examples of RabbitMQ, PostgreSQL and MySQL configurations. Feel free to modify the docker-compose files as needed.

The docker-compose Mistral configurations also include the CloudFlow container. It is available at link

The –build option can be used when it is necessary to rebuild the image, for example:

docker-compose -f tools/docker/docker-compose/infrastructure.yaml \
             -f tools/docker/docker-compose/mistral-single-node.yaml \
             -p mistral up -d --build

Running the Mistral client from the Docker Compose container

To run the mistral client against the server in the container using the client present in the container:

docker run -it mistral_mistral mistral workflow-list

Configuring Mistral

The Docker image contains the minimal set of Mistral configuration parameters by default:

Name

Default value

Description

MESSAGE_BROKER_URL

rabbit://guest:guest@rabbitmq:5672

The message broker URL

DATABASE_URL

sqlite:///mistral.db

The database URL

UPGRADE_DB

false

If the UPGRADE_DB equals true, a database upgrade will be launched before Mistral main process

MISTRAL_SERVER

all

Specifies which mistral server to start by the launch script.

LOG_DEBUG

false

If set to true, the logging level will be set to DEBUG instead of the default INFO level.

RUN_TESTS

false

If the UPGRADE_DB equals true, the Mistral unit tests will be launched inside container

The /etc/mistral/mistral.conf configuration file can be mounted to the Mistral Docker container by uncommenting and editing the volumes sections in the Mistral docker-compose files.

Launch tests inside Container

Build mistral:

docker build -t mistral -f tools/docker/Dockerfile \
      --build-arg BUILD_TEST_DEPENDENCIES=true .

Run tests using SQLite:

docker run -it -e RUN_TESTS=true mistral

or PostgreSQL:

docker run -it \
  -e DATABASE_URL=postgresql://postgres:postgres@localhost:5432/postgres \
  -e RUN_TESTS=true mistral

Keycloak integration

If you set AUTH_ENABLE to True value in the mistral.env file then Mistral will enable Keycloak integration by default. Keycloak will be deployed with mistral/mistral credentials. You should uncomment the volume line in the infrastructure.yaml for the CloudFlow.

Next step you login in the administrative console using the http://localhost:8080/auth/admin URL. Create a oauth client, you can specify only a name, for example mistral.

Specify valid redirect URL: http://localhost:8000/* and turn on the “Implicit Flow Enabled” in the your client page. Save your changes.

Add the following line to your /etc/hosts file:

127.0.0.1   keycloak

Export the following environments variable for mistral cli:

export MISTRAL_AUTH_TYPE=keycloak-oidc
export OS_AUTH_URL=http://keycloak:8080/auth
export OS_TENANT_NAME=master
export OS_USERNAME=mistral
export OS_PASSWORD=mistral
export OS_MISTRAL_URL=http://localhost:8989/v2
export OPENID_CLIENT_ID=mistral
export OPENID_CLIENT_SECRET=
export MISTRALCLIENT_INSECURE=True

Check your configuration:

mistral workflow-list

Or open a cloud flow page in a browser:

http://localhost:8000

Using Mistral Client with Docker

The Mistral API will be accessible from the host machine on the default port 8989. Install python-mistralclient on the host machine to execute mistral commands.

Mistral Client Installation

Please refer to Mistral Client / CLI Guide

Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.