If you've attempted to deploy your ASP.NET 5 MVC 6 apps to Azure from Visual Studio Online or Team Foundation Server, you may have used Microsoft's PowerShell Deployment Scripts. Overall, their script example works really well for basic Azure web apps.
However, their script does not compensate for Azure Web Apps that are either configured with multiple deployment slots, configured with a traffic manager instance, or both.
There are two problematic lines in their script. The first is this:
$website = Get-AzureWebsite -Name $websiteNameThe Get-AzureWebsite commandlet can potentially return a System.Object[]
when there are multiple slots configured for the web app.
Oddly enough, the property mentioned in the next block still returns when
EnabledHostNames is asked for, it just includes all hostnames from the
app. For example, if I have a web app my-azure-website.azurewebsites.net,
with a Staging slot configured, it'll return the following:
This leads to the second issue in the deployment script (comment left intact since it's actually the problem):
# get the scm url to use with MSDeploy. By default this will be the second in the array
$msdeployurl = $website.EnabledHostNames[1]In addition to the multiple slot issue above, we run into another issue when Traffic Manager is configured on the web app. Assuming we have a traffic manager instance called my-azure-website-trafficmanager.trafficmanager.net and one for our staging deployments at my-azure-website-staging-trafficmanager.trafficmanager.net, we can expect an output like this:
We can now see that the code above, looking for an index of 1, will not work
in this scenario. It will end up pushing the actual staging URL to the msdeploy
process, even if we wanted the actual production SCM instance.
Keep in mind that even if we specifically ask for staging through an alternative method (i.e. asking for my-azure-website(Staging)), it would still not work because of Traffic Manager:
To fix these issues, we need to add an optional slot parameter, and then check to make sure we're not getting more web apps or host names than we expect.
Here is the new param line with our change:
param($websiteNames, $packOutput, $slotName)And now checking to see if multiple sites are returned:
$website = if ([string]::IsNullOrWhiteSpace($slotName)) { Get-AzureWebsite -Name $websiteName } else { Get-AzureWebsite -Name $websiteName -Slot $slotName }And finally, specifically seek out our SCM url:
# Grab SCM url to use with MSDeploy; there should only be one
$msdeployurl = $website.EnabledHostNames | Where-Object {$_ -like "*.scm.*"}
if($msdeployurl -is [System.Object[]]) {
throw [System.Exception] "Multiple SCM urls returned for $websiteName; consult Kudu/Azure portal to clarify."
}With those changes, we should be all set!
Here is the actual script that I use in my deployments. Note that I added some additional functionality such as deploying to multiple web apps with the same packaged app and restarting the web app before it is deployed to in an attempt to reduce file locking issues.
#Requires -Version 3.0
param($websiteNames, $packOutput, $slotName)
$VerbosePreference = "continue"
$ErrorActionPreference = "continue"
Write-Verbose "Published requested of the following website(s): $websiteNames"
$websiteNames.split(',') | % {
$websiteName = $_
Write-Verbose "Restarting Azure Websites $websiteName to ensure no locks"
Restart-AzureWebsite -Name $websiteName
Write-Verbose "Starting publish of $websiteName"
$website = if ([string]::IsNullOrWhiteSpace($slotName)) { Get-AzureWebsite -Name $websiteName } else { Get-AzureWebsite -Name $websiteName -Slot $slotName }
# If we have an array, we most likely have additional slots on this website. Throw an exception and leave.
if($website -is [System.Object[]]) {
throw [System.Exception] "Multiple websites returned for $websiteName; please specify a slot"
}
# Grab SCM url to use with MSDeploy; there should only be one
$msdeployurl = $website.EnabledHostNames | Where-Object {$_ -like "*.scm.*"}
if($msdeployurl -is [System.Object[]]) {
throw [System.Exception] "Multiple SCM urls returned for $websiteName; consult Kudu/Azure portal to clarify."
}
$publishProperties = @{'WebPublishMethod'='MSDeploy';
'MSDeployServiceUrl'=$msdeployurl;
'DeployIisAppPath'=$website.Name;
'EnableMSDeployAppOffline'=$true;
'MSDeployUseChecksum'=$true;}
Write-Verbose "Using the following publish properties (excluding username and password):"
Write-Verbose ($publishProperties | Format-List | Out-String)
$publishProperties.Add('Username', $website.PublishingUsername)
$publishProperties.Add('Password', $website.PublishingPassword)
$publishScript = "${env:ProgramFiles(x86)}\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\Microsoft\Web Tools\Publish\Scripts\default-publish.ps1"
Write-Verbose "Running publish script $publishScript"
. $publishScript -publishProperties $publishProperties -packOutput $packOutput
Write-Verbose "Finished publish of $websiteName"
}
Write-Verbose "Finished requested publish of the following website(s): $websiteNames"