OpenStack Configuration

Apart from configuring cASO, several actions need to be performed in your OpenStack installation in order to be able to extract accounting records.

User credentials (required)

In the next section you will configure an OpenStack Keystone credentials in order to extract the records. The cASO user has to be a member of each of the projects (another option is to convert that user in an administrator, but the former option is a safer approach) for which it is extracting the accounting. Otherwise, cASO will not be able to get the usages and will fail.

In order to do so, we are going to setup a new role accounting a new user accounting, adding it to each of the projects with that role:

openstack role create accounting
openstack user create --password <password> accounting
# For each of the projects, add the user with the accounting role
openstack role add --user accounting --project <project> accounting

Moreover, this user needs access to Keystone so as to extract the users information. In this case, we can can grant the user just the rights for listing the users adding the appropriate rules in your /etc/keystone/policy.json as follows. Replace the line:

"identity:list_users": "rule:admin_required",


"identity:list_users": "rule:admin_required or role:accounting",

Recent Keystone versions leverage a /etc/keystone/policy-yaml file, if this is your case, substitute the line:

"identity:list_users": "rule:admin_required"


"identity:list_users": "rule:admin_required or role:accounting"

Publishing benchmark information for OpenStack flavors (optional)

Starting with the V0.4 of the accounting record it is possible to publish benchmark information. In order to do so, you need to add this information to the flavor properties and configure caso to retrieve this information. There are two different values that need to be added to the flavor:

  • The benchmark name, indicated with the accounting:benchmark_name flavor property.
  • The benchmark value, indicated with the accounting:benchmark_value flavor property.

For example, if you are using HEPSPEC06 and the benchmark value is 99 for the flavor, the benchmark information is configured as follows:

openstack flavor set --property accounting:benchmark_name="HEPSPEC06" --property accounting:benchmark_value=99

Using different keys to specify bechmark information

If you do not want to use cASO’s default flavor properties accounting:benchmark_name and accounting:benchmark_value (for example because you are using different benchmark types and values) you can specify which properties cASO should look for by using the benchmark_name_key benchkark_value_key in the configuration file.


Please note that there is an OpenStack scheduler filter that removes hosts based on flavor properties. In order to not interfere with the behaviour of this filter you must prefix the property with a scope: so that cASO’s properties are not taken into account for this filtering. When adding these properties in cASO’s configuration file, please include the complete name (i.e. scope:property).

cASO configuration

cASO uses a config file (default at /etc/caso/caso.conf) with several sections. A sample file is available at etc/caso/caso.conf.sample.

[DEFAULT] section

The [DEFAULT] section configures the basic behavior of cASO. The sample config file (/etc/caso/caso.conf.sample) includes a description of every option. You should check at least the following options:

  • extractor (default value: nova), specifies which extractor to use for getting the data. The following APIs are supported: ceilomenter and nova. Both should generate equivalent information.

  • site_name (default value: <None>). Name of the site as defined in GOCDB.

  • service_name (default value: $site_name). Name of the service within a site. This is used if you have several endpoints within your site.

  • projects (list value, default empty). List of the projects to extract records from. You can use either the project ID or the project name. We recommend that you use the project ID, especially if you are using domain-based authentication, as otherwise gathering the information might fail.

  • messengers (list, default: noop). List of the messengers to publish data to. Records will be pushed to all these messengers, in order. Valid messengers shipped with cASO are:

    • ssm for publishing APEL V0.2 records (deprecated).
    • ssmv2 for publishing APEL V0.2 records (deprecated).
    • ssmv4 for publishing APEL V0.3 records (current).
    • logstash for publishing to Logstash.
    • noop do nothing at all.

    Note that there might be other messengers available in the system if they are registered into the caso.messenger entry point namespace.

  • mapping_file (default: /etc/caso/voms.json). File containing the mapping from VOs to local projects as configured in Keystone-VOMS, in the following form:

        "VO": {
            "projects": ["foo", "bar"],

    Note that you have to use either the project ID or project name for the mapping, as configured in the projects configuration variable.

  • benchmark_name_key and benchmark_value_key. These two configuration options are used by cASO to retrieve the benchmark information form the OpenStack flavors.

[keystone_auth] section

This section is used to specify the authentication credentials to be used to connect to the OpenStack APIs. cASO leverages the OpenStack keystoneauth library for authentication, so that it is possible to use any authentication plugin that is available there (so starting on version 1.0 of cASO it is possible to use the Keystone V3 API).


You need to specify the auth_type that you want to use (normally v3password is a good choice.

For an exhaustive list of available plugins please refer to the keystoneauth documentation.

[ssm] section

Options defined here configure the SSM messenger. There is only one option at the moment:

  • output_path (default: /var/spool/apel/outgoing/openstack), directory to put the generated SSM records. APEL/SSM should be configured to take records from that directory.

[logstash] section

Options defined here configure the logstash messenger. Available options:

  • host (default: localhost), host of Logstash server.
  • port (default: 5000), Logstash server port.

Other cASO configuration options

For an exhaustive list of the defined options, please check the following page: