WindowsFileConfigurator Operator

The WindowsFileConfigurator operator allows configuring systems tuned by Akamas by interpolating configuration parameters into files on remote Windows machines.

The operator performs the following operations:

1. It reads an input file from a remote machine containing templates for interpolating the configuration parameters generated by Akamas

2. It replaces the values of configuration parameters in the input file

3. It writes the file with replaced configuration parameters on a specified path on another remote machine

Access on remote machines is performed using WinRM

Templates for configuration parameters

The Windows File Configurator allows writing templates for configuration parameters in two ways:

• a single parameter is specified to be interpolated:

${component_name.parameter_name}

• all parameters of a component to be interpolated:

${component_name.*}

Adding a suffix or prefix for interpolated parameters

It is possible to add a prefix or suffix to interpolated configuration parameters by acting at the component-type level:

name: Component Type 1
description: My Component type
parameters:
- name: x1
  domain:
    type: real
    domain: [-5.0, 10.0]
  defaultValue: -5.0
  # Under this section, the operator to be used to configure the parameters is defined
  operators:
    WindowsFileConfigurator:
        # using this OPTIONAL confTemplate property is possible to interpolate the parameter value with a prefix and a suffix
        confTemplate: "PREFIX${value}SUFFIX"

In the example above, the parameter x1 will be interpolated with the prefix PREFIX and the suffix SUFFIX, ${value} will be replaced with the actual value of the parameter at each experiment.

Example

Suppose we have the configuration of the following parameters for experiment 1 of a study:

component1.param1: 1024
component1.param2: Category1
component2.param3: 7
component2.param4: 35.4

where component1 is of type MyComponentType defined as follows:

name: MyComponentType
description: "MyComponentType
parameters:
- name: param1
  domain:
    type: real
    domain: [-5.0, 10.0]
  defaultValue: -5.0
  # Under this section, the operator to be used to configure the parameters is defined
  operators:
    WindowsFileConfigurator:
        # using this OPTIONAL confTemplate property is possible to interpolate the parameter value with a prefix and a suffix
        confTemplate: "X1:${value}MB"
# ...

A template file to interpolate only parameter component1.param1 and all parameters from component2 would look like this:

myexecutable.exe /PARAM ${component1.param1} /PARAMS ${component2.*}

The file after the configuration parameters are interpolated would look like this:

myexecutable.exe /PARAM X1:1024MB /PARAMS 7 35.4

Note that the file in this example contains a bash command whose arguments are constructed by interpolating configuration parameters. This represents a typical use case for the WindowsFileConfigurator: to construct the right bash commands that configure a system with the new configuration parameters computed by Akamas.

Operator arguments

Name	Type	Value Restrictions	Required	Default	Description
source	Object	It should have a structure like the one defined in the next section	No, if the Component whose name is defined in component has properties that map to the ones defined within source		Information relative to the source/input file to be used to interpolate optimal configuration parameters discovered by Akamas
target	Object	It should have a structure like the one defined in the next section	No, if the Component whose name is defined in component has properties that map to the ones defined within target		Information relative to the target/output file to be used to interpolate optimal configuration parameters discovered by Akamas
component	String	It should match the name of an existing Component of the System under test	No		The name of the Component whose properties can be used as arguments of the operator

source and target structure and arguments

Here follows the structure of either the source or target operator argument

Name	Type	Value Restrictions	Required	Default	Description
hostname	String	It should be a valid host address	Yes		Windows host
username	String		Yes		Login username
password	String	Windows password for the specified user	Yes		Login password
path	String	It should be a valid path	Yes		The path of the file to be used either as the source or target of the activity to applying Akamas computed configuration parameters using files

Get operator arguments fromcomponent

The component argument can be used to refer to a Component by name and use its properties as the arguments of the operator. In case the mapped arguments are already provided to the operator, there is no override.

Notice that in this case, the operator replaces in the template file only tokens referring to the specified component. A parameter bound to any component causes the substitution to fail.

Component property to operator argument mapping

Component property	Operator argument
hostname	source->hostname target->hostname
username	source->username target->username
password	source->password target->password
sourcePath	source->path
targetPath	target->path

Examples

Configure parameters for an Apache server with explicit source and target information

name: RemoteConfOperatorTestStandalone
operator: WindowsFileConfigurator
arguments:
  source:
    hostname: template-server
    username: akamas-user1
    password: akamas-password1
    path: C:\templates\frontned-httpd.conf
  target:
    hostname: frontend-server
    username: akamas-user2
    password: akamas-password22
    path: c:\httpd\httpd.conf

Configure parameters for an Apache server with information taken from a Component

name: RemoteConfOperatorTestStandalone
operator: WindowsFileConfigurator
arguments:
  component: apache-server-1

Where the apache-server-1 component is defined as:

name: apache-server-1
description: The Apache server instance
componentType: Apache Server 2.4

properties:
  hostname: apache.akamas.io
  username: administrator
  sourcePath: c:\template\httpd.conf.template
  targetPath: c:\httpd\httpd.conf