PowerShell on Ash Tewari

Kusto Queries on AKS Clusters

Sun, 25 Apr 2021 19:40:55 +0000

Kusto query language can be used to get insights into Azure Kubernetes Service (AKS) clusters. Container insights collects data from AKS clusters and forwards it to Log Analytics workspace, if enabled for a cluster. This data is available for querying in the Azure Monitor. Here is an example of how you can query the pods not in running state in specific namespaces.

KubePodInventory
| where Namespace in ("dv","test","prod")
| where ContainerStatus != "Running"
| where ContainerStatusReason !in ("", "Completed")
| distinct Namespace, Name

The following query includes the name of the AKS cluster and renders the output as a stacked bar chart.

KubePodInventory
| where Namespace in ("dv","test","prod")
| where ContainerStatus != "Running"
| where ContainerStatusReason !in ("", "Completed")
| distinct ClusterName, Namespace, Name
| summarize dcount(Name) by ClusterName, Namespace
| render columnchart kind=stacked100

You can include multiple AKS clusters in the scope in which this query is executed by clicking on [Select scope] hyperlink.

Create an Azure Dashboard panel with this output by clicking on [Pin to dashboard] button.

You can also execute this Kusto query directly using powershell.

$workspaceName = "DefaultWorkspace-6637b095-xxxx-xxxx-xxxx-xxxxxxxxxxx-EUS"
$workspaceRG = "defaultresourcegroup-eus"
$WorkspaceID = (Get-AzOperationalInsightsWorkspace -Name $workspaceName -ResourceGroupName $workspaceRG).CustomerID

$query = 'KubePodInventory | where Namespace in ("dv","test","prod") | where ContainerStatus != "Running" | where ContainerStatusReason !in ("", "Completed") | distinct ClusterName, Namespace, Name | summarize dcount(Name) by ClusterName, Namespace'

$result = Invoke-AzOperationalInsightsQuery -WorkspaceId $WorkspaceID -Query $query -Timespan (New-TimeSpan -days 1)
$result.results

This allows you to include the results of your custom Kusto queries in any reports you might run using Azure Automation Runbooks.

AKS Supported Kubernetes Versions

Mon, 09 Nov 2020 03:08:17 +0000

Azure Kubernetes Service (AKS) supports specific versions of Kubernetes.
It is necessary to regularly monitor the release of new versions and upgrade your AKS clusters to supported versions in order to remain in compliance with AKS Kubernetes Version Support Policy.

AKS announces the planned date of a new minor version release and corresponding old version deprecation via AKS Release notes at least 30 days prior to removal. An email notification is sent to the subscription administrators with the planned version removal dates. You get 30 days from version removal to upgrade to a supported minor version release. Patch versions can be released anytime and you get 30 days from the removal date to upgrade to a supported patch version.

You should test new target Kubernetes versions and upgrade your AKS clusters in a timely manner. For that, it is necessary to proactively monitor the AKS release notes. This can easily become a chore in a large Enterprise environment. Here is a Powershell script to make it easier to stay on top of Kubernetes version releases in AKS and publish/share it with others: Get-AksSupportedVersions.

$aksVersionsJson = az aks get-versions --location eastus

$aksVersions = $aksVersionsJson | ConvertFrom-Json
$aksVersions.orchestrators.upgrades.orchestratorVersion

$data = $aksVersions.orchestrators | Select-Object `
 -Property @{Name="Version";Expression={$_.orchestratorVersion}} `
 , @{Name="Default";Expression={$_.default}} `
 , @{Name="Preview";Expression={$_.isPreview}} `
 , @{Name="Upgrades";Expression={$_.upgrades.orchestratorVersion -join ", "}}

$versionTable = $data | ConvertTo-Html -Fragment
$versionTableString = $versionTable | Out-String
$html = New-Object -ComObject "HTMLFile"
$html.IHTMLDocument2_write($versionTableString)
$tables = $html.body.getElementsByTagName("table")

$rptString = ""
ForEach($table in $tables){
 ForEach($row in $table.rows){
 $cellCount = 0
 ForEach($cell in $row.cells){
 $cellCount++
 if(($cellCount -eq 2) -and ($cell.innertext -eq 'True'))
 {
 $row.className = "OkStatus"
 }
 if(($cellCount -eq 3) -and ($cell.innertext -eq 'True'))
 {
 $row.className = "WarningStatus"
 }
 }
 }
 $rptString += $table.outerHTML
}

$reportDate = $(get-date -DisplayHint DateTime) | Out-String
$fileTS = $(get-date -Format "yyyyMMdd")
$fileName = "aks-versions-$fileTS.html"

$rptTitle = "<h1>AKS Kubernetes Versions</h1><p>$reportDate</p>"
$report = ConvertTo-Html -Title "AKS Versions" -Body "$rptTitle $rptString" -Head $header
$report | Out-File "$fileName"

It creates an HTML report of currently supported Kubernetes versions in AKS along with their respective upgrade paths. Here is an example of the report generated by the script referenced above :

AKS Kubernetes Versions

Sunday, November 8, 2020 8:47:42 PM

Version	Default	Preview	Upgrades
1.16.13			1.16.15, 1.17.9, 1.17.11
1.16.15			1.17.9, 1.17.11
1.17.9			1.17.11, 1.18.6, 1.18.8
1.17.11	True		1.18.6, 1.18.8
1.18.6			1.18.8, 1.19.0
1.18.8			1.19.0
1.19.0		True

Reference: How To Create An HTML Report With PowerShell

Using Powershell with Splunk

Tue, 23 Feb 2016 03:20:14 +0000

Splunk Powershell Resource Kit is a convenient and very capable wrapper over Splunk REST API. You can use the Powershell commandlets exposed by this resource kit to deploy, check and manage splunk services as well as execute splunk searches. In this post, you will be introduced to the Splunk Powershell Resource Kit, you will learn how to use powershell commandlets to connect to a splunk instance and execute searches.

1. First, you will need to download the resource kit from github. 2. Installation is very simple. All you have to do is download and extract the files from the zip archive and double click on install.bat to install the splunk powershell module. 3. Open Windows Powershell console from Windows Start menu. 4. Verify that the Splunk module is installed by executing Get-Module commandlet.

Get-Module SplunkSearch

5. Import splunk resource kit commandlets using Import-Module command.

Import-Module -Name Splunk

6. Next, you need to use Get-Credentials and then Connect-Splunk commandlets to connect to splunk. You need to do this once per session or if you need to switch to a different splunk instance.

$credential = Get-Credential
Connect-Splunk -Credential $credential -ComputerName localhost

I have a local Splunk Enterprise instance running on my machine, so I am using localhost as the ComputerName to connect to it. If you have a SplunkCloud subscription you can use YourSubscriptionId.splunkcloud.com as the ComputerName to connect to your subscription. Like so -

Connect-Splunk -Credential $credential -ComputerName MySubscription.splunkcloud.com

7. Next, use Search-Splunk commandlet to execute searches -

Search-Splunk -Search "Error"

Here is a sample script:

$lastDay = ( get-date ).addDays( -1 ).toString( ‘s’ )

$searches = @(
 "ERROR"
 , "source=""tutorialdata.zip:*"" ERROR"
 , "CreditDoesNotMatch"
 ,"source=""tutorialdata.zip:.\\www3/access.log"" productId=WC-SH-G04"
)

Write-Output $lastDay
foreach($search in $searches)
{
 $qry = $search + " | stats count"
 Write-Output $qry
 Search-Splunk -Search $qry -StartTime $lastDay | Select-Object -ExpandProperty Count
}

The sample script executes multiple Splunk searches and outputs the count of results matching these search queries. Note that I am “-StartTime” parameter to scope the search to a narrower time window and “stats count” command to get the count of results. You can get this sample script as a github gist.

You can also use -EndTime and –MaxReturnCount to further constrain the query results and Format-List, Format-Table, Format-Wide commands to format the results. You can learn more about other Search parameters as well as other capabilities exposed in the resource kit documentation.

Resources :

Image credit : terminal by Andrea Mazzini from the Noun Project

Code Validation in TortoiseSVN pre_commit_hook

Thu, 01 Apr 2010 04:32:10 +0000

If you want to abort a commit if your code fails certain rule and you don’t have access to the SVN Server to configure a hook. What do you do ?

Assuming you are using TortoiseSVN, you can configure a Client-Side hook.

Here is an example - Say you want to abort commit if you have a comment in your code that starts with //Do Not Commit. You can create a PowerShell script that validates all the files in your changeset and use this script as a Client-Side pre_commit_hook in TortoiseSVN.

TortoiseSVN-Settings-HookScripts

The pre_commit_hook configuration :

Configure-Hook-Scripts

//Powershell script : pre_commit.ps1

$donotcommit = “//Do Not Commit”;

$changeset = Get-Content$args[0];

foreach($file in $changeset) { if( Get-Content$file | Select-String$donotcommit-quiet ) { Write-Error “$file contains code that you are not supposed to commit. [$donotcommit]”; exit9; } }

Now, if your changeset has a file with a comment starting with //Do Not Commit and you click on OK to commit this change, the commit will be aborted with this error message -

pre_commit_hook-validation