Author Archives: Chris

Improving Documentation via the Community.

Have you ever had to deal with incorrect documentation? Or been frustrated by a typo? Or been annoyed that a how-to guide uses an old version of an interface?

Now you can fix it!

Many software providers are now using community-editable documentation online. This isn’t a Wikipedia style free-for-all, but a carefully moderated process ensuring that the resulting document is accurate.  If you come across an error in an online doc, or even a PowerShell help page, check and see if you can submit edits.

Continuous deployment pipelines mean that these edits can make it into live documentation in a matter of hours or days- impressive times if you’ve ever submitted an errata to a printed book, or submitted a bug request to get online documentation fixed.

docs.Microsoft.com

If you visit a Microsoft docs page, you’ll see an Edit link at the top of the screen (see (1) in the screenshot below). Clicking on this takes you to a page on Github with the source of the document. Click there to edit the file and a git fork will be made under your own profile- make your edits and submit a merge request and, once approved, your updates will appear in the original website. You’ll even get a little credit (see (2) in the screenshot below) for your contribution.

image

In this particular example I was following the step-by-step guide and noticed that the wording in the document no longer matched the Azure Portal. I was quickly able to suggest a fix and later that day the page was updated and anyone else following the instructions wouldn’t be misled. Two minutes of my time hopefully saved ten minutes of head-scratching by someone else.

VMware PowerCLI Example Scripts

As the name suggests, the source code for some example PowerCLI scripts has been published by VMware supported by members of the #vCommunity. If you find an error in the scripts you can pop over to Github and correct them- and remember this isn’t just the code of the script, but also it’s accompanying documentation.

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In this example a typo in the get-help file was spotted and quickly corrected. Whilst the spelling mistake wasn’t a show-stopper this shows how quick and easy it is to contribute to these projects without being a coding guru.

Summary

Many of these projects use Github and learning how to use that version control platform isn’t arduous- especially for small changes like these- and is a useful skill to pickup if you don’t already have it. The important message here is you don’t need to be a developer to contribute to the code.

So, next time you spot a mistake in documentation, see if you can fix it yourself and help the next person who comes along.

Azure: Deploy a WebApp with PowerShell

A quick runthrough on using PowerShell to deploy a new WebApp. ASP.NET code for the website has been zipped up (into myapp.zip) and this code snippet will upload it to a new WebApp, hosted in a new App Service Plan and a new Resource Group.

From a local PowerShell session use Connect-AZAccount before running this code to sign-in to Azure. Alternatively this code can be run (with the exception of the upload itself) from the Cloud Shell directly in the Azure Portal.

The code also writes out the URL of the resulting WebApp and the PowerShell necessary to tear down the resources when they are no longer required.

#Set some parameters
$location="UK South"
$resourceGroupName= “rsg-myapp”
$webAppName=”web-myapp”
$appServicePlanName=”asp-myapp”
$codeZIPPath=”C:\myapp.zip”

#Create Resource Group
"-- Creating Resource Group"
New-AzResourceGroup -Location $location -Name $resourceGroupName -tag $Tags

#Create ServicePlan
"-- Creating Service Plan"
New-AzAppServicePlan -ResourceGroupName $resourceGroupName -Name $appServicePlanName -Location $location -Tier Free

#Create Web App
"-- Creating Web App"
New-AzWebApp -ResourceGroupName $resourceGroupName -Name $webAppName -Location $location -AppServicePlan $appServicePlanName

#Upload the web code
"-- Uploading Web App Code"
Publish-AzWebApp -ResourceGroupName $resourceGroupName -Name $webAppName -ArchivePath $codeZIPPath –Force

#Show user code to destroy this (useful for testing)
#  and the website that has been created.
"-- Tidy Up Code: "
" Remove-AzResourceGroup -Name $resourceGroupName"
"-- Website: "
"-- https://$WebAppName.azurewebsites.net"

"-- Done"

The resulting website can be viewed just by pointing a browser at the given URL. The created resources can be checked in the Azure portal:

image

vSAN Cluster Shutdown

A few weeks ago I had to shutdown a vSAN Cluster temporarily for a planned site-wide 24 hour power outage that was blacking out a datacentre. With the amount of warning and a multi-datacentre design this wasn’t an issue, but I made use of vSphere tags and some Powershell/PowerCLI to help with the evacuation and repopulation of the affected cluster. Hopefully some of this may be useful to others.

The infrastructure has two vSAN Clusters – Cluster-Alpha and Cluster-Beta. Cluster-Beta was the one being affected by the power outage, and there was sufficient space on Cluster-Alpha to absorb migrated workloads. Whilst they exist in different datacentres both clusters are on the same LAN and under the same vCenter.

I divided the VMs on Cluster-Beta into three categories:

  1. Powered-Off VMs and Templates. These were to stay in place, they would be inaccessible for the outage but I determined this wouldn’t present any issues.
  2. VMs which needed to migrate and stay on. These were tagged with the vSphere tag “July2019Migrate”
  3. VMs which needed to be powered off but not migrated. For example test/dev boxes which were not required for the duration. These were tagged with “July2019NOMigrate”

The tagging was important, not only to make sure I knew what was migrating and what was staying, but also what we needed to move back or power on once the electrical work had completed. PowerCLI was used to check that all powered-on VMs in Cluster-Beta were tagged one way or another.

Get the VMs in CLuster-Beta where the tag “July2019Migrate” is not assigned and the tag “July 2019NOMigrate” is not assigned and the VM is Powered On.

Get-Cluster -Name "Cluster-Beta" |Get-VM | where {
 (Get-TagAssignment -Entity $_).Tag.Name –notcontains "July2019Migrate" –and
 (Get-TagAssignment -Entity $_).Tag.Name –notcontains "July2019NOMigrate" –and
 $_.PowerState –eq “PoweredOn”}

In the week approaching the shutdown the migration was kicked off:

#Create a List of the VMs in the Source Cluster which are tagged to migrate
$MyTag= Get-Tag -Name "July2019Migrate"
$MyVMs=Get-Cluster "Cluster-Beta" | Get-VM | Where-Object {(Get-TagAssignment -Entity $_).Tags -contains $MyTag }
#Do the Migration
$TargetCluster= "Cluster-Alpha" #Target Cluster
$TargetDatastore= "vSANDatastore-Alpha" #Target Datastore on Target Cluster
$MyVMs | Move-VM -Destination (Get-Cluster -Name $TargetCluster) -Datastore (Get-Datastore -Name $TargetDatastore) -DiskStorageFormat Thin -VMotionPriority High

At shutdown time, a quick final check of the remaining powered on VMs was done and then all remaining VMs in Cluster-Beta were shut down. Once there were no running workloads on Beta it was time to shut down the vSAN cluster. This part I didn’t automate as I’m not planning on doing it a lot, and there’s comprehensive documentation in the VMware Docs site. The process is basically one of putting all the hosts into maintenance mode and then once the whole cluster is done, powering them off.

You are in a dark, quiet datacentre. There are many servers, all alike. There may be Grues here.

When power was restored, the process was largely reversed. I powered on the switches providing the network interconnect between the nodes, and then powered on those vSAN hosts and waited for them to come up. Once all the hosts were visible to vCenter, it was just a case of selecting them all and choosing “Exit Maintenance Mode”

2019-07-29 (8)

There was a momentary flash of alerts as nodes come up and wonder where their friends are, but in under a minute the cluster was passing the vSAN Health Check

image

At this point it was all ready to power on the VMs that had been shutdown and left on the cluster, and vMotion the migrated virtual machines back across. Again, PowerCLI simplified this process:

#Create a List of the VMs in the Source Cluster which are tagged to stay but need powering on.
$MyTag= Get-Tag -Name "July2019NOMigrate"
$MyVMs=Get-Cluster “Cluster-Alpha” | Get-VM | Where-Object {(Get-TagAssignment -Entity $_).Tags -contains $MyTag }
#Power on those VMs
$MyVMs | Start-VM

#Create a List of the VMs in the Source Cluster which are tagged to migrate (back)
$MyTag= Get-Tag -Name "July2019Migrate"
$MyVMs=Get-Cluster “Cluster-Alpha” | Get-VM | Where-Object {(Get-TagAssignment -Entity $_).Tags -contains $MyTag }
#Do the Migration
$TargetCluster= "Cluster-Beta" #New Target Cluster
$TargetDatastore= "vSANDatastore-Beta" #Target Datastore on Target Cluster
$MyVMs | Move-VM -Destination (Get-Cluster -Name $TargetCluster) -Datastore (Get-Datastore -Name $TargetDatastore) -DiskStorageFormat Thin -VMotionPriority High

Then it was just a case of waiting for the data to flow across the network and finally check that everything had migrated successfully and normality had been restored.

we have normality, I repeat we have normality…Anything you still can’t cope with is therefore your own problem. Please relax.

Trillian, via the keyboard of Douglas Adams. The Hitchhiker’s Guide to the Galaxy

Microsoft Azure Fundamentals

Earlier this week I took and passed the Microsoft AZ-900 exam- the requirement for the Microsoft Azure Fundamentals badge. Whilst this is the entry-level cert and not a requirement for the more advanced ones in the pathways, it is still useful for experienced techies moving into the Azure space, perhaps from other cloud platforms or on-premises architectures.

I had some prior experience dabbling in Azure, so wasn’t coming into this green. This was coupled with my general experience in server and cloud technologies so the generic concepts weren’t new to me. But I personally found working to the certification a useful way of ensuring I have a good grounding in the platform and specific terminologies before moving onto other things.

azure-fundamentals-600x600

Learning Materials

There’s plenty of material out there, including a new book, but I studied by going through the free online “Azure fundamentals” learning path from Microsoft: https://docs.microsoft.com/en-us/learn/paths/azure-fundamentals/

This is a series of articles, short videos, and mini-tests with a couple of practical exercises in the Azure Portal thrown in. It covers everything from the basics (what is cloud computing etc.) through to some of the specific Azure products which are in the exam syllabus.

I coupled this learning pathway with some further exploration and experimentation in the Azure Portal and associated documentation.

The Exam

The exam itself- once all the pre-ramble, surveys, and commenting sections are removed – is 60 minutes and my test had (IIRC) 44 questions. The first 5/6 questions were in a separate section where I couldn’t revisit them once I’d answered and moved on, but for the remainder I was able to go back and forth and review as necessary.

Question Styles

No, I’m not going to reveal what questions I was asked, but knowing the way the questions can be asked in advance is helpful. It’s been some years since I took a Microsoft exam and question styles change.

My particular test (and remember, they’re all different) had a mixture of multiple choice (sometimes just one of four answers, sometimes more than one may have been required) and drag-and-drop answers. Within the multiple choice there were also a number of questions where I was given a statement and had to replace (if necessary) the words given in bold. For example (and this is obviously not a real AZ-900 question!)

The Microsoft Solitaire game was first released with Windows 95 to help introduce the graphical user interface.

Review the text in bold. If it makes the statement correct select “No change needed”, otherwise select the answer which makes the statement correct.

  • A-No change needed
  • B-Windows 3.0
  • C-Windows Bob
  • D-OS X

Correct Answer- B

Check out the “Exam formats and question types” videos from Microsoft for more detail.

Subjects Covered

The subjects are fully covered in the “Skills Measured” section of the exam webpage and I felt there was a good match between these lists and the questions I was posed on the day.

Going into this with a firm background in the generic cloud concepts the trickiest part for me was matching up which Azure product does what and remembering the names. I’d recommend making sure you’ve remembered as many as possible of these from the core offerings- and also be prepared to spot fake product names in the multiple choice (I’m pretty sure I saw a few of these). For example (and again, not a real AZ-900 question!)

In Microsoft Windows 10, which application could you use to assign local administrator rights to an Active Directory user.

  • A-Active Directory Users and Computers
  • B-Local Users and Groups
  • C-Windows Administrator Control
  • D-Microsoft Rights Manager

Correct Answer- B. As far as I know C and D don’t exist.

Conclusion

I’m obviously happy with my pass, and I’d recommend looking at this to anyone starting out on an Azure journey, possibly from scratch or by transitioning from other technologies. The exam isn’t compulsory, but it does validate your learning- either to yourself or your employer.