Setting Azure App Service server stack on a Bicep template - azure-web-app-service

Question

I'm trying to deploy a .NET Core 3.1 Azure App Service on Linux using a Bicep template from Azure CLI. The app service and corresponding app service plan are deployed correctly but the app service stack settings are empty on the Azure portal and I have to set these manually. I tried setting the metadata property on the 'Microsoft.Web/sites' resource and also on the 'Microsoft.Web/sites/config' resource, but the result was the same.
This is my app service plan:
resource appServicePlan 'Microsoft.Web/serverfarms#2021-02-01' = {
name: 'MyAppService'
location: resourceGroup().location
properties: {
reserved: true
}
sku: {
name: 'P1v2'
}
kind: 'linux'
}
Here is my first attempt to set the stack using 'Microsoft.Web/sites' as suggested here:
https://github.com/Azure/bicep/issues/3314
resource appService 'Microsoft.Web/sites#2021-02-01' = {
name: 'MyApp'
location: resourceGroup().location
identity: {
type: 'SystemAssigned'
}
kind: 'app'
properties: {
enabled: true
serverFarmId: appServicePlan.id
siteConfig: {
linuxFxVersion: 'dotnet|3.1'
appCommandLine: 'dotnet MyApp.dll'
metadata: [
{
name: 'CURRENT_STACK'
value: 'dotnetcore'
}
]
}
}
}
Here is my second attempt to set the stack using 'Microsoft.Web/sites/config' as suggested here:
Bicep - How to config Runtime Stack to Azure App Service (Bicep version 0.4)
resource appService 'Microsoft.Web/sites#2021-02-01' = {
name: 'MyApp'
location: resourceGroup().location
identity: {
type: 'SystemAssigned'
}
kind: 'app'
properties: {
enabled: true
serverFarmId: appServicePlan.id
siteConfig: {
linuxFxVersion: 'dotnet|3.1'
appCommandLine: 'dotnet MyApp.dll'
}
}
resource webConfig 'config' = {
name: 'web'
properties: {
metadata: [
{
name: 'CURRENT_STACK'
value: 'dotnetcore'
}
]
}
}
}
The result is the same. The deployment is completed with the following warning:
Warning BCP037: The property "metadata" is not allowed on objects of
type "SiteConfig". Permissible properties include
"acrUseManagedIdentityCreds", "acrUserManagedIdentityID", "alwaysOn",
"apiDefinition", "apiManagementConfig", "autoHealEnabled",
"autoHealRules", "autoSwapSlotName", "azureStorageAccounts",
"connectionStrings", "cors", "defaultDocuments",
"detailedErrorLoggingEnabled", "documentRoot", "experiments",
"ftpsState", "functionAppScaleLimit",
"functionsRuntimeScaleMonitoringEnabled", "handlerMappings",
"healthCheckPath", "http20Enabled", "httpLoggingEnabled",
"ipSecurityRestrictions", "javaContainer", "javaContainerVersion",
"javaVersion", "keyVaultReferenceIdentity", "limits", "loadBalancing",
"localMySqlEnabled", "logsDirectorySizeLimit", "managedPipelineMode",
"managedServiceIdentityId", "minimumElasticInstanceCount",
"minTlsVersion", "netFrameworkVersion", "nodeVersion",
"numberOfWorkers", "phpVersion", "powerShellVersion",
"preWarmedInstanceCount", "publicNetworkAccess", "publishingUsername",
"push", "pythonVersion", "remoteDebuggingEnabled",
"remoteDebuggingVersion", "requestTracingEnabled",
"requestTracingExpirationTime", "scmIpSecurityRestrictions",
"scmIpSecurityRestrictionsUseMain", "scmMinTlsVersion", "scmType",
"tracingOptions", "use32BitWorkerProcess", "virtualApplications",
"vnetName", "vnetPrivatePortsCount", "vnetRouteAllEnabled",
"websiteTimeZone", "webSocketsEnabled", "windowsFxVersion",
"xManagedServiceIdentityId". If this is an inaccuracy in the
documentation, please report it to the Bicep Team.
[https://aka.ms/bicep-type-issues]
The resources are deployed, but the app service stack setting is blank and I have to set it manually to make it work.
I know that in the ARM template this is set on the CURRENT_STACK property of the Microsoft.Web/sites/config metadata (as suggested here https://cloudstep.io/2020/11/18/undocumented-arm-oddities-net-core-app-services/). However, this doesn't seem to be supported (yet) in Bicep. If anyone has found a working solution, please post it here.
Thanks.

Answer 1

The Metadata parameter is not available anymore in the SiteConfig. The stack setting can be mentioned LinuxFxVersion.
So, solution will be Instead of using dotnet|3.1 , You should use DOTNETCORE|3.1.The over all code will be as below:
resource appServicePlan 'Microsoft.Web/serverfarms#2021-02-01' = {
name: 'MyAppService'
location: resourceGroup().location
properties: {
reserved: true
}
sku: {
name: 'P1v2'
}
kind: 'linux'
}
resource appService 'Microsoft.Web/sites#2021-02-01' = {
name: 'anumantestapp'
location: resourceGroup().location
identity: {
type: 'SystemAssigned'
}
kind: 'app'
properties: {
enabled: true
serverFarmId: appServicePlan.id
siteConfig: {
linuxFxVersion: 'DOTNETCORE|3.1'
appCommandLine: 'dotnet MyApp.dll'
}
}
}
Ouptut: