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

Sahara is packaged with a basic sample configuration file: sahara.conf.sample-basic. This file contains all the essential parameters that are required for sahara. We recommend creating your configuration file based on this basic example.

If a more thorough configuration is needed we recommend using the tox tool to create a full configuration file by executing 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 copying the basic example or generating one, 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://username:password@host:port/database

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

auth_uri=http://127.0.0.1:5000/v2.0/
identity_uri=http://127.0.0.1:35357/

Specify the admin_user, admin_password and admin_tenant_name. These parameters must specify an Identity user who has the admin role in the given tenant. 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:

use_neutron=true

If you are using nova-network for networking then this parameter should be set to false.

With these parameters set, sahara is ready to run.

If you wish to increase the logging levels for troubleshooting there are two parameters in the [DEFAULT] section of the configuration file which control the level of logging output; verbose and debug. With verbose set to true sahara’s default logging level will be set to INFO, and with debug set to true it will be set to DEBUG. By default the sahara’s log level is set to WARNING.

Networking configuration

By default sahara is configured to use the nova-network implementation of OpenStack Networking. If an OpenStack cluster uses neutron, then the use_neutron parameter should be set to True in the sahara configuration file. Additionally, if the cluster supports network namespaces the use_namespaces property can be used to enable their usage.

[DEFAULT]
use_neutron=True
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:

• If using the nova-network, it may be configured to assign floating IP addresses automatically by setting the auto_assign_floating_ip parameter to True in the nova configuration file (usually nova.conf).
• 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. Whether using nova-network or neutron it is important to ensure that all instances running sahara have access to the fixed IP networks.

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

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.json 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.