Use the Starter device

Use the Starter device#

audience:all

Introduction#

The Starter device can be used to control other device servers running on the same host.

Possible use cases are:

  • start all device servers on system startup,

  • get a list of all started device servers,

  • start or stop a device server,

  • get logs from a device server.

Astor is a graphical client for Starter devices.

Installation#

There are several ways to install the Starter device server:

Configuration#

General recommendations for configuring the Starter:

  • there should be only one instance of a Starter device server running on a host,

  • the instance name can be arbitrary,

  • the Starter device server provides a Starter class,

  • the member part of a Starter device name must match the short name of the host.

  • the domain/family part of a Starter device name should be “tango/admin” in order for the Starter device to be detected by Astor.

Below is an example of how to define a Starter device using the tango_admin tool:

host=$(hostname -s)
tango_admin --add-server Starter/$host Starter tango/admin/$host
Starter $host

Note

The requirement for the member part of the name to match the hostname can be disabled by setting the environment variable DEBUG to true. The starter will be visible in Astor under the name specified in member.

Usage#

The Astor GUI can be used to start a new Tango device server using the Starter device.

Alternatively, the Starter interface can be used directly, e.g. to start a device server:

import tango
starter = tango.DeviceProxy("tango/admin/tangobox")
starter.command_inout("DevStart", "TangoTest/test")

The Starter device will use the paths from the StartDsPath property when looking for an executable of a device server to start. The paths are searched in the order in which they appear in the property. If the property is empty, Starter device server’s working directory is used when searching for executables.

Autostarting Starter#

The Starter device server can be automatically started during system startup using a service manager of choice. It can then start any other device server.

The following are example configuration files for different service managers:

Further references#