Friday, February 03, 2017

Powershell problem : With remote PSSession, Running EXE in path with spaces and getting back response using Write-Output

I think some of the most trouble I've recently had in coding Powershell has been trying to run an executable on a remote Hyper-V VM that was located under Program Files and then actually getting the response back properly so I could iterate though the results.

The first trickiness was with running the command properly when there were spaces in the path.

In double quotes you have to use the ampersand (&) and then write the path to the EXE in single quotes and then at the end of the string before the closing quotes character, append an argument.

For example :

$commandLocation = "& 'C:\Program Files\....\application_name.exe' argument"

This is the proper syntax that you can then pass to an Invoke-Expression that's inside a ScriptBlock called by Invoke-Command. Invoke-Expression is a very helpful commandlet to run EXEs, when, for example, running Powershell on a remote machine.

The second issue was understanding how I could use Write-Output to pipe the remote call output back a Powershell variable within the ScriptBlock that I could then use in the calling function.

I read that you could use 4>&1 at the end of the ScriptBlock but never found it useful in my case.

Here's some example code :

Function RunConsulCommandOnXM([string] $blahParameter, [string] $remoteMachineAddress)
{

    $defaultBlahCommandLocation = "& 'C:\Program Files\...\blah.exe' "

    WriteLogAndConsole "Default blah directory : $defaultBlahCommandLocation"
 
    $fullCommand = $defaultBlahCommandLocation +  $blahParameter

    WriteLogAndConsole "Full command with arguments being run : $fullCommand"

    $scriptToExecute = { param($passedCommand)
        begin {
            Write-Host "Start of command:"
        }
        process {
            $consoleOutput = Invoke-Expression -Verbose -Command $passedCommand
        }
        end {
            Write-Host "Output from remote command:"
            Write-Host $consoleOutput
            Write-Host "************"
            Write-Output $consoleOutput
            }
     }

    $blahCommandResult = Invoke-Command -Session $global:session -Verbose -ScriptBlock $scriptToExecute -ArgumentList $fullCommand

    #Write-Host "Result of blah argument command: " $blahCommandResult

    return $blahCommandResult

}

Thursday, January 19, 2017

Powershell New-PS Drive using Administrator credentials. User name or password is incorrect

Sometimes you forget the obvious when your doing scripting.

Although not recommended, I was using powershell to create a new psdrive session using the Administrator.

Problem is that with just Administrator and the password, powershell was complaining about a bad username and password combination.

Since the VM was connected to a development domain I wasn't qualifying the Administrator name therefore confusing powershell.

I add the computername\Administrator and tried again. Much better success

Wednesday, December 21, 2016

Elasticsearch analogies

I work a lot with Elasticsearch.

At my job we have migrated from using SQL Server to Elasticsearch for log storage.

Sometimes, when you're learning new grammar for a new technology you're working on it's nice to have metaphors or similes to use when learning the component parts.

One of the best similies I've heard of for what Elasticsearch represents is that it's like an index at the end of a book. Additionally, Elasticsearch by many, even those who work at Elastic, consider it not a DB.

If you start using Elasticsearch a lot more you'll begin to work with types, templates and mappings.

A type could be analogous to a regular SQL table.

Mappings could be similar to a a table column that stores a field a certain way that could be something like a string, int, varchar.

How mappings and settings are created and loaded has changed from Elasticsearch 1.x to 2.x+. Now that we use Elasticsearch 2.x we have to load template files that are used when new indices are created. They combine settings and the mappings for the fields that get parsed out and placed into an index.

Thanks to this website for giving me those Aha! analogies.

http://swops.com/blog/elasticsearch-mappings-and-templates

Rebuild project of 18 year old Mansfield Toilet

I just completed a toilet rebuild last weekend. The toilet began leaking a year or two ago; especially during warm weather.

Although I wasn't working the whole time the total time from start to finish was a half day. I did initial work and investigations starting Friday night, I let the tank dry out overnight, and I finished about 1 PM the following day having started around 10 AM with the installation of the new parts on the tank.

Actual time working was probably around 4 hours.

Work entailed replacing the fill valve, flush valve, new bolts attaching the tank to the bowl, new shutoff valve and supply line too.





New shutoff valve
New Supply Line to Tank
All parts replaced in dry tank
Tank full with water

All parts were ordered from Mansfield and the cost was just under 50 bucks. I went to Home Depot for the new shutoff valve and supply line.

Total cost was about 60 bucks.

Issues encountered after the replacement was slight leaking from one of the bolts, which I had to tighten down more to prevent further leakage.

As mentioned on my Twitter post, I'd say this home project was a 2-3 out of 10.



Wednesday, July 20, 2016

Perl : subroute redefined, prototype mismatch

I was refactoring my code and placing some common methods into a base module in my Perl lib directory.

Unfortunately some of my new method names had name collisions with possible subroutines in other packages.

I was able to rename the methods that I was exporting for use in my PL files and the errors went away.

Wednesday, March 30, 2016

Python Indentation Error

I've only been using Python for a year.

Before that, my focuses were Java and Perl.

An interesting error I came across, since Python has stricter criteria for formatting was: "IndentationError: expected an indented block"

The code in question:






The error might be considered a red herring since the problem with the else: statement was that there was no real code to run after the if statement.

Once I added a logging statement:






The error went away.

Friday, June 12, 2015

Setting up a new hyper-v Windows 2012 server to be pingable and allow RDP connections

At my current company we are needing to test deployments not only to Linux but Windows too.

To quickly have preconfigured systems come up we use virtualization (Hyper-V) along with other technologies like Vagrant and Ansible with other configuration and testing scripts like Python and/or Powershell.

I just setup a new Windows 2012 R2 Machine in Hyper-V using a ISO image.

By default, some features aren't enabled to make my testing easier. For example, to be able to ping the machine or RDP into it for GUI related tasks.

To enable Windows to respond to a ping you have to go into Windows Firewall with Advanced Security > Inbound Rules and enable File and Printer Sharing (Echo Request - ICMPv4-In) by right clicking on the rule name.

For remote desktop connections I had to do two things:

1) Type SystemPropertiesRemote and select "Allow remote connections to this computer."  I also deselected the "Allow connections only..." beneath it
2) I ran this command: netsh advfirewall firewall set rule group="Remote Desktop" new enable=yes

If for some reason I disabled Allow remote connections again I would have to do the two steps again to get RDP to allow my remote client to connect.

Friday, May 08, 2015

Caveats/setup notes for running pytest with Jenkins on Windows 2012 R2 server

I've been writing test code in Python for the last few weeks.  Although it's been great to have Perl and Java as my predominant testing languages, it is nice to try a new scripting language on for size.

I first used Python on Linux and this last week - due to testing requirements - I needed to use it on Windows.

Python Installation :

Installing Python is pretty straightforward. Go to python.org. and download it. Installation is very easy.

After the install, I needed to add the Python to the System Path.

Pip and Pytest Installation :

Pip seemed a little different to install -vs- Linux. With Linux I could install with yum and call pip directly. To use Pip on Windows I had to call it through Python first

Installing Pytest then required me calling Python to call pip and then install PyTest. See below:

python -m pip install pytest

With Pytest installed I needed to incorporate it into my Python test class:

1) Import PyTest in the Python script using : import pytest.
2) Use an assert statement for test results.
3) Place the test statements in a test method (def testSomething(): )  For the tests to work correctly with JUnit output I needed to put the asserts in a test method.
4) Create JUnit output for Jenkins. When I did run my basic test class without outputting to an XML file it seemed to work just fine, but if I wanted to get results to Jenkins I needed to get an XML file for Jenkins to read.
5) Once I solved the above issues I needed to make sure a JUnit XML file was created. This is how I called it below:

python -m pytest scripts\CheckMSIBuildStatus.py --junitxml=results.xml