Remove files and foldes on Azure before a new deploy from VSTS

Question

As part of my build process in VSTS I want to delete all files and folders (except af few) from my azure site before a new deploy. My guess is, that using a Azure Powershell script would be a good idea and I would prefer making an inline script.

I am using Azure Resource Manager as connection type, I have selected my subscription and script type (Inline Script) but then I am lost, how do i select my app service and, for a start, list my files?

Trying just, this for a test, only gives my files in my VSTS environment

Get-ChildItem -Path $(build.sourcesDirectory)

Answer 1

First, it’s better to include the files to the project that the web app needs, then just check Remove additional files at destination option (Check Publish using Web Deploy option first) to remove additional files.

Secondly, you can remove the files through Kudu API.

DELETE /api/vfs/{path}    (Delete the file at path)

More information, you can refer to: Interacting with Azure Web Apps Virtual File System using PowerShell and the Kudu API

Update (Add Kudu sample):

1. Add Azure PowerShell step/task
2. Sepcify arguments, for example: -resourceGroupName XXX -webAppName XXX -kuduPath Global.asax

Script:

param(
    [string]$resourceGroupName,
    [string]$webAppName,
    [string]$slotName="", 
    [string]$kuduPath
)
function Get-AzureRmWebAppPublishingCredentials($resourceGroupName, $webAppName, $slotName = $null){
    if ([string]::IsNullOrWhiteSpace($slotName)){
        $resourceType = "Microsoft.Web/sites/config"
        $resourceName = "$webAppName/publishingcredentials"
    }
    else{
        $resourceType = "Microsoft.Web/sites/slots/config"
        $resourceName = "$webAppName/$slotName/publishingcredentials"
    }
    $publishingCredentials = Invoke-AzureRmResourceAction -ResourceGroupName $resourceGroupName -ResourceType $resourceType -ResourceName $resourceName -Action list -ApiVersion 2015-08-01 -Force
    Write-Host $publishingCredentials   
    return $publishingCredentials
}
function Get-KuduApiAuthorisationHeaderValue($resourceGroupName, $webAppName, $slotName = $null){
    $publishingCredentials = Get-AzureRmWebAppPublishingCredentials $resourceGroupName $webAppName $slotName
    Write-Host $publishingCredentials.Properties.PublishingUserName
    Write-Host $publishingCredentials.Properties.PublishingPassword
    return ("Basic {0}" -f [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $publishingCredentials.Properties.PublishingUserName, $publishingCredentials.Properties.PublishingPassword))))
}
function Delete-FileToWebApp($resourceGroupName, $webAppName, $slotName = "", $kuduPath){

    $kuduApiAuthorisationToken = Get-KuduApiAuthorisationHeaderValue $resourceGroupName $webAppName $slotName
    if ($slotName -eq ""){
        $kuduApiUrl = "https://$webAppName.scm.azurewebsites.net/api/vfs/site/wwwroot/$kuduPath"
    }
    else{
        $kuduApiUrl = "https://$webAppName`-$slotName.scm.azurewebsites.net/api/vfs/site/wwwroot/$kuduPath"
    }

    Write-Output $kuduApiUrl
    Write-Output $kuduApiAuthorisationToken
    Invoke-RestMethod -Uri $kuduApiUrl `
                        -Headers @{"Authorization"=$kuduApiAuthorisationToken;"If-Match"="*"} `
                        -Method DELETE
}

Delete-FileToWebApp $resourceGroupName $webAppName $slotName $kuduPath

Answer 2

Here's a tweaked version of the script which should be included in your project and exported as an artefact as part of your build, I call mine Delete-WebAppFiles.ps1

It expands on the previous answer by also handling virtual applications and having error handling for the case when the files do not exist e.g. on first deployment to a new environment

param(
    [string]$resourceGroupName,
    [string]$webAppName,
    [string]$appPath="wwwroot",
    [string]$slotName="", 
    [string]$kuduPath,
    [bool]$recursive=$false
)
function Get-AzureRmWebAppPublishingCredentials($resourceGroupName, $webAppName, $slotName = $null){
    if ([string]::IsNullOrWhiteSpace($slotName)){
        $resourceType = "Microsoft.Web/sites/config"
        $resourceName = "$webAppName/publishingcredentials"
    }
    else{
        $resourceType = "Microsoft.Web/sites/slots/config"
        $resourceName = "$webAppName/$slotName/publishingcredentials"
    }
    $publishingCredentials = Invoke-AzureRmResourceAction -ResourceGroupName $resourceGroupName -ResourceType $resourceType -ResourceName $resourceName -Action list -ApiVersion 2015-08-01 -Force
    Write-Host $publishingCredentials   
    return $publishingCredentials
}
function Get-KuduApiAuthorisationHeaderValue($resourceGroupName, $webAppName, $slotName = $null){
    $publishingCredentials = Get-AzureRmWebAppPublishingCredentials $resourceGroupName $webAppName $slotName
    Write-Host $publishingCredentials.Properties.PublishingUserName
    Write-Host $publishingCredentials.Properties.PublishingPassword
    return ("Basic {0}" -f [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $publishingCredentials.Properties.PublishingUserName, $publishingCredentials.Properties.PublishingPassword))))
}
function Delete-KuduFile($resourceGroupName, $webAppName, $appPath, $slotName, $kuduPath, $recursive){

    $kuduApiAuthorisationToken = Get-KuduApiAuthorisationHeaderValue $resourceGroupName $webAppName $slotName
    if ($recursive -eq $true) {
        if (-not ($kuduPath.endswith("recursive=true"))) {
           if (-not ($kuduPath.endswith("/"))) {
              $kuduPath += "/"
           }
           $kuduPath += "?recursive=true"
        }
    }
    if ($slotName -eq ""){
        $kuduApiUrl = "https://$webAppName.scm.azurewebsites.net/api/vfs/site/$appPath/$kuduPath"
    }
    else{
        $kuduApiUrl = "https://$webAppName`-$slotName.scm.azurewebsites.net/api/vfs/site/$appPath/$kuduPath"
    }

    Write-Output $kuduApiUrl
    Write-Output $kuduApiAuthorisationToken

    try
    {
        Invoke-RestMethod -Uri $kuduApiUrl `
                        -Headers @{"Authorization"=$kuduApiAuthorisationToken;"If-Match"="*"} `
                        -Method DELETE
    } catch {
        Write-Host "StatusCode:" $_.Exception.Response.StatusCode.value__ 
        Write-Host "StatusDescription:" $_.Exception.Response.StatusDescription
        if (-not ($_.Exception.Response.StatusCode.value__ -eq 404)) {
            throw $PSItem
        }
    }    
}

Delete-KuduFile $resourceGroupName $webAppName $appPath $slotName $kuduPath $recursive

You can then add a Powershell task as mentioned above which should look a little like this...

Answer 3

This is how you can test your settings that you use in the PowerShell scripts above using Postman.

I found it useful to play with the REST API using Postman to understand what the PowerShell scripts above were doing and understand what status codes I could expect back from the API. I also noticed that the recursive logic for deleting a directory returns a 409 Conflict error even though is DOES delete the files.

In the examples below, my app service is called "YatesDeleteMe"

Create a base 64 encoded username and password string to use below in your authorization header OR run the PowerShell scripts above and it will output one for you

1. Download your app service's publish file, which can be downloaded from the Overview tab in the Azure portal.
2. Open the file with a text editor
3. Find the username (user name example: $YatesDeleteMe ) and password (password example: ch222cDlpCjx4Glq333qo4QywGPMs1cK2Rjrn6phqZ9HswtgEEE12CrhDmcn )
4. Create a string out of them and separate them with a colon (should look something like this: $YatesDeleteMe:ch222cDlpCjx4Glq333qo4QywGPMs1cK2Rjrn6phqZ9HswtgEEE12CrhDmcn )
5. Base 64 encode them using your own program a site. The result should look something like this: JFlhdGVzRGVsZXRlTWU6Y2gyMjJjRGxwQ2p4NEdscTMzM3FvNFF5d0dQTXMxY0syUmpybjZwaHFaOUhzd3RnRUVFMTJDcmhEbWNu

Retrieve a single file

1. Open Postman
2. Change the verb to GET
3. Enter your URL to the file you want to retrieve (e.g., https://YatesDeleteMe.scm.azurewebsites.net/api/vfs/site/wwwroot/web.config). For more info on paths see this
4. Added a header-->
   • Key: Authorization
   • Value: Basic YourBase64EncodedStringFromAbove
5. Left-click the "Send" button and the file will download

Delete a single file

1. Open Postman
2. Change the verb to DELETE
3. Enter your URL to the file you want to delete (e.g., https://YatesDeleteMe.scm.azurewebsites.net/api/vfs/site/wwwroot/web.config)
4. Added a header-->
   • Key: Authorization
   • Value: Basic YourBase64EncodedStringFromAbove
5. Added a header-->
   • Key: If-Match
   • Value: *
6. Left-click the "Send" button and the file will deleted

Delete all the files in a directory

1. Open Postman
2. Change the verb to DELETE
3. Enter your URL to the folder you want to delete PLUST add slash and then the query string ?recursive=true (e.g., https://YatesDeleteMe.scm.azurewebsites.net/api/vfs/site/wwwroot/?recursive=true)
4. Added a header-->
   • Key: Authorization
   • Value: Basic YourBase64EncodedStringFromAbove
5. Added a header-->
   • Key: If-Match
   • Value: *
6. Left-click the "Send" button and the folder will deleted. I always get a 409 error back, but the folder is deleted.

Reference

• Blog post with pictures here.