Powershell script task

[patrickfarry]

I wrote a small extension task that embeds a powershell script. We will be using it for complex build tasks. The script can access the Nant project object (get and set properties etc.). It also supports named powershell runspaces - so you can continue executing a script after setting up the parameters.

Anyone interested in this? I haven't contributed anything before - not sure if it is worthy or how to go about it.

Here is an example of the task in NAnt

The top level build file. $var = "this is the script" $myvar.Properties["tmpLog"] = "Hello" $myvar.Project.ProjectName $var = "running from a new runspace" $var $var

[patrickfarry]

Sorry - that looks ugly - here is my test build file

<project name="My project" default="build" basedir=".">
  <description>The top level build file.</description>

  <property name="tmpLog" value="c:\tempSVNUpdate" />
  <property name="results" value="Unknown" />

<target name="build" >
    <powershell  property="results"  taskvar = "myvar" runspace="myrunspace">
        $var = "this is the script"
        $myvar.Properties["tmpLog"] = "Hello"
        $myvar.Project.ProjectName
    </powershell>
    <powershell  property="results">
        $var = "running from a new runspace"
        $var
    </powershell>
    <powershell  property="results" runspace="myrunspace">
        $var
    </powershell>

</target>
</project>

[patrickfarry]

Here is the source - -

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
using NAnt.Core;
using NAnt.Core.Attributes;
using System.Management.Automation;
using System.Management.Automation.Runspaces;

namespace PowershellPlugin
{
[TaskName("powershell" )]
public class PowershellTask : Task
{

  private string _runspaceName = string.Empty;
  private string _taskVarName = "task";
  private bool _isNamedRunspace = false;
  private string _property = string.Empty;
  static private Dictionary<string, Runspace> _namedSession;


  [TaskAttribute("runspace", Required = false)]
  [StringValidator(AllowEmpty = false)]
  public string RunspaceName
  {
      get { return _runspaceName; }
      set { _isNamedRunspace = true; _runspaceName = value; }
  }

  [TaskAttribute("taskvar", Required = false)]
  [StringValidator(AllowEmpty = false)]
  public string TaskVar
  {
      get { return _taskVarName; }
      set { _taskVarName = value; }
  }

  [TaskAttribute("property", Required = false)]
  [StringValidator(AllowEmpty = false)]
  public string Property
  {
      get { return _property; }
      set { _property = value; }
  }


    public PowershellTask()
    {
        _runspaceName = String.Empty;
        if (_namedSession == null)
        {
            object l = new object();
            lock (l)
            {
                if (_namedSession == null)
                {
                    _namedSession = new Dictionary<string, Runspace>();
                }
            }
        }

    }




  protected override void ExecuteTask()
  {
      Runspace runspace = null;

      try
      {


          StringBuilder scriptText = new StringBuilder();
          scriptText.Append(XmlNode.InnerText);
            object l = new object();
            lock (l)
            {

                if (!_namedSession.TryGetValue(_runspaceName, out runspace))
                {
                    InitialSessionState iss = InitialSessionState.CreateDefault();
                    SessionStateVariableEntry thisTask = new SessionStateVariableEntry(_taskVarName, this, "The task being called in nant");
                    iss.Variables.Add(thisTask);
                    runspace = RunspaceFactory.CreateRunspace(iss);

                    if (_isNamedRunspace)
                    {
                        _namedSession.Add(_runspaceName, runspace);
                    }
                    runspace.Open();

                }
            }
          PowerShell ps = PowerShell.Create();
          ps.Runspace = runspace;
          ps.AddScript(scriptText.ToString());
          Collection<PSObject> results = ps.Invoke();
          StringBuilder resultString = new StringBuilder();
          if (_property != String.Empty)
          {
              foreach (PSObject po in results)
              {

                 resultString.AppendLine(po.ToString());

              }
              this.Properties[_property] = resultString.ToString();
          }
      }
      finally
      {
          if (!_isNamedRunspace && runspace != null)
          {
              runspace.Close();
              runspace.Dispose();
          }
      }

  }

}
}

[dguder]

Here is the source - -
(now using github markdown)

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
using NAnt.Core;
using NAnt.Core.Attributes;
using System.Management.Automation;
using System.Management.Automation.Runspaces;

namespace PowershellPlugin
{
    [TaskName("powershell" )]
    public class PowershellTask : Task
    {

      private string _runspaceName = string.Empty;
      private string _taskVarName = "task";
      private bool _isNamedRunspace = false;
      private string _property = string.Empty;
      static private Dictionary<string, Runspace> _namedSession;


      [TaskAttribute("runspace", Required = false)]
      [StringValidator(AllowEmpty = false)]
      public string RunspaceName
      {
          get { return _runspaceName; }
          set { _isNamedRunspace = true; _runspaceName = value; }
      }

      [TaskAttribute("taskvar", Required = false)]
      [StringValidator(AllowEmpty = false)]
      public string TaskVar
      {
          get { return _taskVarName; }
          set { _taskVarName = value; }
      }

      [TaskAttribute("property", Required = false)]
      [StringValidator(AllowEmpty = false)]
      public string Property
      {
          get { return _property; }
          set { _property = value; }
      }


        public PowershellTask()
        {
            _runspaceName = String.Empty;
            if (_namedSession == null)
            {
                object l = new object();
                lock (l)
                {
                    if (_namedSession == null)
                    {
                        _namedSession = new Dictionary<string, Runspace>();
                    }
                }
            }

        }




      protected override void ExecuteTask()
      {
          Runspace runspace = null;

          try
          {


              StringBuilder scriptText = new StringBuilder();
              scriptText.Append(XmlNode.InnerText);
                object l = new object();
                lock (l)
                {

                    if (!_namedSession.TryGetValue(_runspaceName, out runspace))
                    {
                        InitialSessionState iss = InitialSessionState.CreateDefault();
                        SessionStateVariableEntry thisTask = new SessionStateVariableEntry(_taskVarName, this, "The task being called in nant");
                        iss.Variables.Add(thisTask);
                        runspace = RunspaceFactory.CreateRunspace(iss);

                        if (_isNamedRunspace)
                        {
                            _namedSession.Add(_runspaceName, runspace);
                        }
                        runspace.Open();

                    }
                }
              PowerShell ps = PowerShell.Create();
              ps.Runspace = runspace;
              ps.AddScript(scriptText.ToString());
              Collection<PSObject> results = ps.Invoke();
              StringBuilder resultString = new StringBuilder();
              if (_property != String.Empty)
              {
                  foreach (PSObject po in results)
                  {

                     resultString.AppendLine(po.ToString());

                  }
                  this.Properties[_property] = resultString.ToString();
              }
          }
          finally
          {
              if (!_isNamedRunspace && runspace != null)
              {
                  runspace.Close();
                  runspace.Dispose();
              }
          }

      }

   }
}

[patrickfarry]

Do you what the whole solution?

[dguder]

First of all I wanted to see the whole code. Do you have any tests?
Some review:

• Your lock object should be defined at class level.
• What happens if powershell could not be found? (e.g on WinXP or on mono on linux?)
• Some comments for documentation are required (see other nantcontrib source files)

[rmboggs]

I like the idea. If you are wanting to submit this task to NAntContrib, I would ask if you could submit this via a pull request, details can be found here.

Documentation for this task would also be very helpful. :)

[patrickfarry]

I don' t have anything else. Happy to spend some time bringing it up to
standard.

I will look at the other contrib projects and figure out what to do. Will
send an update when I get it done.

Cheers.

Connected by DROID on Verizon Wireless

-----Original message-----
From: Dominik Guder
<reply+i-2528372-b66055b90339b6ceec05f59b133e8fb0fc42c4db-1258583@reply.githu
b.com>
To: patrickfarry [email protected]
Sent: Mon, Dec 12, 2011 23:01:25 GMT+00:00
Subject: Re: [nantcontrib] Powershell script task (#5)

First of all I wanted to see the whole code. Do you have any tests?
Some review:

• Your lock object should be defined at class level.
• What happens if powershell could not be found? (e.g on WinXP?)
• Some comments for documentation is required (see other nantcontrib source
  files)

---

Reply to this email directly or view it on GitHub:
#5 (comment)

[patrickfarry]

Will do. I got mail from Dominik. I will be upgrading what I did to fit the
project and will get back to you guys.

Connected by DROID on Verizon Wireless

-----Original message-----
From: Ryan Boggs
<reply+i-2528372-b66055b90339b6ceec05f59b133e8fb0fc42c4db-1258583@reply.githu
b.com>
To: patrickfarry [email protected]
Sent: Mon, Dec 12, 2011 23:14:02 GMT+00:00
Subject: Re: [nantcontrib] Powershell script task (#5)

I like the idea. If you are wanting to submit this task to NAntContrib, I
would ask if you could submit this via a pull request, details can be found
here.

Documentation for this task would also be very helpful. :)

---

Reply to this email directly or view it on GitHub:
#5 (comment)

[rmboggs]

Sounds great.

[andrewducker]

Did this ever get merged in?