Merging hashtables

Hash tables in PowerShell are very useful and can be used for a bunch of things.   Recently I had to use some code I found on StackOverflow to Merge hash tables. This post is about my experience and the really cool piece of code that iRon posted on StackOverFlow.

First I need to login to azure and find my application:



I see my resource in the Get-azureRmresource so now I know that I can query for it’s app settings using this command:

$myapp = Get-AzureRmWebAppSlot -resourcegroupname myresourcegroup -name myresourcename -slot production

This produces and object that contains all my web application settings in azure for my app in question.  The item i want to work on is the .siteconfig.AppSettings


This portion of the object will have the properties of the appsettings in the azure blade as shown below:


PS C:\Users\me> $myApp.siteconfig.AppSettings

Name Value


Now that I have the current version of what is in my application I now need to see what to do to put new settings in place and not wipe out any existing settings.  The cmdlet to do the addition is Set-AzureRmWebAppSlot.  After looking through the help I can see that I have a parameter that  I can pass for the settings i want called -appSettings.  It like most of the other settings require a hash table:  [[-AppSettings] <Hashtable>]

So The $myApp.SiteConfig.Appsettings is a list:

$appSettings = $Myapp.siteconfig.appsettings
&amp;nbsp;$appsettings -is [pscustomobject]

IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True List`1 System.Object

$appsettings -is [hashtable]

This means I need to convert my object from List`1 to a hashtable so I’ll iterate through it and create a hashtable:

$appSettingsHash = @{}
&amp;nbsp;foreach($k in $appSettings) { $appSettingsHash[$] = $k.value }

Name Value
---- -----

&amp;nbsp;$appsettingshash -is [hashtable]


Ok now that I have my current settings in a hashtable I need to now work with entries that I want to add to a hashtable and then post it.

$appSettings ='{"AppSettings:testkey1": "45test","AppSettings:TestId": "This is a Test Key 28"}'

$newAppSettings = $appSettings | convertfrom-json 

$newAppSettingsHash = @{}
 $ | ForEach-Object { $newAppSettingsHash[$_.Name] = $_.Value }

$newappsettingsHash -is [hashtable]

This is where the magic of iRon‘s script comes into play. Since  I need to use this in a deployment from TFS I created the hashtable in Json Format first and then convert the Json format to a [hashtable]. Then I call iRon’s Script with the $newappSettingsHash and the $appsettingsHash. Now I have a merged hashtable that I can now update my application with.

Function Merge-Hashtables([ScriptBlock]$Operator) {
$Output = @{}
ForEach ($Hashtable in $Input) {
If ($Hashtable -is [Hashtable]) {
ForEach ($Key in $Hashtable.Keys) {$Output.$Key = If ($Output.ContainsKey($Key)) {@($Output.$Key) + $Hashtable.$Key} Else {$Hashtable.$Key}}
If ($Operator) {ForEach ($Key in @($Output.Keys)) {$_ = @($Output.$Key); $Output.$Key = Invoke-Command $Operator}}

$hashtable = $newAppSettingsHash, $appSettingsHash | Merge-Hashtables {$_[0]} 
$results = Set-AzureRmWebAppSlot -AppSettings $hashtable -name $website -ResourceGroupName $resourceGroup -slot $slot
$r = $results.SiteConfig.AppSettings
Write-Output $r

The really cool thing about the Merging of the hashtables function is that you can merge more than 2 hash tables.  See this comment from iRon about how it works:



Full code for this merge hashtable function against a azure application is below:

I hope that when you need to merge hashtables this article makes it a  bit easier for you.


Until then keep scripting



Uploading files to Azure Applications (kudu)

I needed to copy some content to my azure application that the Build and deploy that I constructed for it wouldn’t need to do every deploy every time.   So my quest began on how do I upload files to an Azure application.  The most common and recognized way of uploading files to azure applications is through webdeploy. I didn’t think I needed to package up and use webdeploy so I sought out a way to do this with PowerShell.  This post is about that pursuit.

Thanks to this article most of the work was done Copy files to Azure Web App with PowerShell and Kudu API.  All I needed to do was to put a loop around my file upload and use Octavie van Haaften‘s scripts.

So I started with get-childitem -recurse “$downloadFolder\content”.  Now that I had my content in a variable called $files I can put this in a foreach loop and use Octavie van Haaften‘s  Upload-FileToWebapp.

During the upload of the files I need to determine if the file from my local disk is a File or Directory.  I used the following classes to determine this:

[System.IO.DirectoryInfo] &  [System.IO.FileInfo]

If the item was a directory then I had to make the upload location match the location on disk.  I did this through a little bit of replacement logic and used the $kudufolder as my variable to use for the upload function from Octavie.

$kudufolder = ((($file.FullName).Replace($uploadfrom,'Content'))`
$kudufolder = "$kudufolder/"
Upload-FileToWebApp -resourceGroupName myresourcegroup`
-webAppName mywebapp -kuduPath $kudufolder

The same holds true for the upload of a file. The only difference between the file and the directory is the /. When you are uploading/creating a directory / to kudu means a directory.

$kudufile = ((($file.FullName).Replace($uploadfrom,'Content'))`
Upload-FileToWebApp -resourceGroupName myresourcegroup`
-webAppName mywebapp -localPath $file.FullName -kuduPath $kudufile

Here is the full script in the foreach loop with each check for a directory or file.

$downloadfolder = 'c:\temp\myAzureStorage'

$uploadfrom = "$downloadfolder\Content"

$files = get-childitem -Recurse "$downloadfolder\Content"

foreach($file in $files)
if($file -is [System.IO.DirectoryInfo])
$kudufolder = ((($file.FullName).Replace($uploadfrom,'Content')).replace('\','/')).trimstart('/')
$kudufolder = "$kudufolder/"
Upload-FileToWebApp -resourceGroupName myresourcegroup -webAppName mywebapp -kuduPath $kudufolder
elseif($file -is [System.IO.FileInfo])
$kudufile = ((($file.FullName).Replace($uploadfrom,'Content')).replace('\','/')).trimstart('/')
Upload-FileToWebApp -resourceGroupName myresourcegroup -webAppName mywebapp -localPath $file.FullName -kuduPath $kudufile

I hope this helps someone
Until then keep Scripting