PreStep element

Article
03/28/2018

Defines the PreStep stage of a custom diagnostic test, The PreStep stage performs validation and prepares the environment for running the test.

Usage

<PreStep
  Command = "character_string"
  ResultXml = "boolean">
  child elements
</PreStep>

Attributes

Attribute Type Required Description

Attribute	Type	Required	Description
Command	character_string	Yes	Specifies the command line for the command or application that you want to run for the PreStep stage of the test. You can specify any command or application that you can run from a command prompt, if performs the tasks described in Diagnostic Test Stages. Possible commands include command-line commands, command files or batch files, instances of Windows PowerShell, and compiled console applications. If the command that you want to specify includes quotation marks (such as a command that includes a path with spaces) or other special characters in XML, use character entities to specify the characters, for example, `"`. For more information about character entities, see Character and Entity References (https://go.microsoft.com/fwlink/p/?linkid=165386). The maximum length of the command line is 255 characters.
ResultXml	boolean	No	Indicates whether the test generates a PreStepResult.xml file in the working directory on the head node. True indicates that test generates a PreStepResult.xml file that the diagnostic service should use to obtain the results of the stage. This file can specify a node list that overrides the list of nodes the user specified when the user started the test. This file also specifies custom parameters for the RunStep stage of the test. If the PreStepResult.xml file contains an empty Nodes element, the test fails. If the PreStepResult.xml file does not contains a Nodes element, the RunStep stage runs on the nodes that the user specified when the user started the test. False indicates that the diagnostic service should not use the information in the PreStepResult.xml file, and that the diagnostic service should check the last line of standard output of the PreStep command for a node list, rather than check the PreStep.xml file. If the last line of standard output has a format of Nodes: Node1, Node2,..., the diagnostic service runs the RunStep stage on the nodes in that list. If the last line does not start with Nodes, the RunStep stage runs on the nodes that the user specified when the user started the test. If the last line starts with Nodes but does not specify any nodes, the test fails.

Command

character_string

Yes

Specifies the command line for the command or application that you want to run for the PreStep stage of the test.

You can specify any command or application that you can run from a command prompt, if performs the tasks described in Diagnostic Test Stages. Possible commands include command-line commands, command files or batch files, instances of Windows PowerShell, and compiled console applications.

If the command that you want to specify includes quotation marks (such as a command that includes a path with spaces) or other special characters in XML, use character entities to specify the characters, for example, ". For more information about character entities, see Character and Entity References (https://go.microsoft.com/fwlink/p/?linkid=165386).

The maximum length of the command line is 255 characters.

ResultXml

boolean

Indicates whether the test generates a PreStepResult.xml file in the working directory on the head node.

True indicates that test generates a PreStepResult.xml file that the diagnostic service should use to obtain the results of the stage. This file can specify a node list that overrides the list of nodes the user specified when the user started the test. This file also specifies custom parameters for the RunStep stage of the test. If the PreStepResult.xml file contains an empty Nodes element, the test fails. If the PreStepResult.xml file does not contains a Nodes element, the RunStep stage runs on the nodes that the user specified when the user started the test.

False indicates that the diagnostic service should not use the information in the PreStepResult.xml file, and that the diagnostic service should check the last line of standard output of the PreStep command for a node list, rather than check the PreStep.xml file. If the last line of standard output has a format of Nodes: Node1, Node2,..., the diagnostic service runs the RunStep stage on the nodes in that list. If the last line does not start with Nodes, the RunStep stage runs on the nodes that the user specified when the user started the test. If the last line starts with Nodes but does not specify any nodes, the test fails.

Child elements

Element	Description
EnvironmentVariables	Represents a set of one or more environment variables that you want to set for the PreStep stage of the diagnostic test.
Parameter	Defines a set of one or more parameters for the PreStep stage in the diagnostic test.

EnvironmentVariables

Represents a set of one or more environment variables that you want to set for the PreStep stage of the diagnostic test.

Parameter

Defines a set of one or more parameters for the PreStep stage in the diagnostic test.

Child element sequence

Parameter?EnvironmentVariables?

Parent elements

Element	Description
DiagnosticTest	Defines a custom diagnostic test, including the metadata, parameters, environment variables, and commands for the test.

DiagnosticTest

Defines a custom diagnostic test, including the metadata, parameters, environment variables, and commands for the test.

Remarks

The PreStep stage of a diagnostic test runs only on the head node. A PreStep element is required in the test definition for a diagnostic test that runs a job.

Element information

Schema file	DiagnosticTests.xsd
Can be empty	Yes