Sahara Configuration Guide

This guide covers the steps for a basic configuration of sahara. It will help you to configure the service in the most simple manner.

Basic configuration

A full configuration file showing all possible configuration options and their defaults can be generated with the following command:

$ tox -e genconfig

Running this command will create a file named sahara.conf.sample in the etc/sahara directory of the project.

After creating a configuration file by either generating one or starting with an empty file, edit the connection parameter in the [database] section. The URL provided here should point to an empty database. For example, the connection string for a MySQL database will be:

connection=mysql+pymsql://username:password@host:port/database

Next you will configure the Identity service parameters in the [keystone_authtoken] section. The www_authenticate_uri parameter should point to the public Identity API endpoint. The auth_url should point to the internal Identity API endpoint. For example:

www_authenticate_uri=http://127.0.0.1:5000/v3/
auth_url=http://127.0.0.1:5000/v3/

Specify the username, user_domain_name, password, project_name. and project_domain_name. These parameters must specify an Identity user who has the admin role in the given project. These credentials allow sahara to authenticate and authorize its users.

Next you will configure the default Networking service. If using neutron for networking the following parameter should be set in the [DEFAULT] section:

With these parameters set, sahara is ready to run.

By default the sahara’s log level is set to INFO. If you wish to increase the logging levels for troubleshooting, set debug to true in the [DEFAULT] section of the configuration file.

Networking configuration

By default sahara is configured to use the neutron. Additionally, if the cluster supports network namespaces the use_namespaces property can be used to enable their usage.

[DEFAULT]
use_namespaces=True

Note

If a user other than root will be running the Sahara server instance and namespaces are used, some additional configuration is required, please see Non-root users for more information.

Floating IP management

During cluster setup sahara must access instances through a secure shell (SSH). To establish this connection it may use either the fixed or floating IP address of an instance. By default sahara is configured to use floating IP addresses for access. This is controlled by the use_floating_ips configuration parameter. With this setup the user has two options for ensuring that the instances in the node groups templates that requires floating IPs gain a floating IP address:

• The user may specify a floating IP address pool for each node group that requires floating IPs directly.

From Newton changes were made to allow the coexistence of clusters using floating IPs and clusters using fixed IPs. If use_floating_ips is True it means that the floating IPs can be used by Sahara to spawn clusters. But, differently from previous versions, this does not mean that all instances in the cluster must have floating IPs and that all clusters must use floating IPs. It is possible in a single Sahara deploy to have clusters setup using fixed IPs, clusters using floating IPs and cluster that use both.

If not using floating IP addresses (use_floating_ips=False) sahara will use fixed IP addresses for instance management. When using neutron for the Networking service the user will be able to choose the fixed IP network for all instances in a cluster.

Notifications configuration

Sahara can be configured to send notifications to the OpenStack Telemetry module. To enable this functionality the following parameter enable should be set in the [oslo_messaging_notifications] section of the configuration file:

[oslo_messaging_notifications]
enable = true

And the following parameter driver should be set in the [oslo_messaging_notifications] section of the configuration file:

[oslo_messaging_notifications]
driver = messaging

By default sahara is configured to use RabbitMQ as its message broker.

If you are using RabbitMQ as the message broker, then you should set the following parameter in the [DEFAULT] section:

rpc_backend = rabbit

You may also need to specify the connection parameters for your RabbitMQ installation. The following example shows the default values in the [oslo_messaging_rabbit] section which may need adjustment:

rabbit_host=localhost
rabbit_port=5672
rabbit_hosts=$rabbit_host:$rabbit_port
rabbit_userid=guest
rabbit_password=guest
rabbit_virtual_host=/

Orchestration configuration

By default sahara is configured to use the heat engine for instance creation. The heat engine uses the OpenStack Orchestration service to provision instances. This engine makes calls directly to the services required for instance provisioning.

Policy configuration

Warning

JSON formatted policy file is deprecated since Sahara 15.0.0 (Xena). This oslopolicy-convert-json-to-yaml tool will migrate your existing JSON-formatted policy file to YAML in a backward-compatible way.

Sahara’s public API calls may be restricted to certain sets of users by using a policy configuration file. The location of the policy file(s) is controlled by the policy_file and policy_dirs parameters in the [oslo_policy] section. By default sahara will search for a policy.yaml file in the same directory as the sahara.conf configuration file.

Examples

Example 1. Allow all method to all users (default policy).

{
    "default": ""
}

Example 2. Disallow image registry manipulations to non-admin users.

{
    "default": "",

    "data-processing:images:register": "role:admin",
    "data-processing:images:unregister": "role:admin",
    "data-processing:images:add_tags": "role:admin",
    "data-processing:images:remove_tags": "role:admin"
}

API configuration

Sahara uses the api-paste.ini file to configure the data processing API service. For middleware injection sahara uses pastedeploy library. The location of the api-paste file is controlled by the api_paste_config parameter in the [default] section. By default sahara will search for a api-paste.ini file in the same directory as the configuration file.