Custom functions in Azure ARM Templates

Azure provides a helpful number of functions which can be used in ARM templates. It makes our life easier.

We can see the complete list of Azure ARM function here

Apart from that in some situations, you may find your self where you need to implement custom function inside ARM templates. So we can reuse it. So it is DRY.

Typically, we use complicated logic inside the function that we don’t want to duplicate in the ARM template.

So is it possible in ARM template? Yes, ARM templates give us the opportunity to implement custom functions. 🙂

Keep in mind. There are some restrictions when we use functions as below.

  • The function can’t access variables.
  • The function can only use parameters that are defined in the function. When you use the parameters function within a user-defined function, you’re restricted to the parameters for that function.
  • The function can’t call other user-defined functions.
  • The function can’t use the reference function.
  • Parameters for the function can’t have default values

The custom function should be declared inside functions property in an ARM template.

Following is a sample function which accepts the container name as a parameter and appends resource group location to container name.

{
"$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"functions": [
{
"namespace": "rt",
"members": {
"containerNameWithLocation": {
"parameters": [
{
"name": "containerName",
"type": "string"
}
],
"output": {
"type": "string",
"value": "[concat(parameters('containerName'), resourceGroup().location)]"
}
}
}
}
],
"parameters":{
"containerName": {
"type": "string",
"defaultValue": "blobcontainer"
}
}
}

Note that parameters used in scope of function should be declared in parameters section in ARM template.

Your functions require a namespace value to avoid naming conflicts with template functions. In above function we have used rt as namespace.

 

Then we can call the function as below

rt.containerNameWithLocation(parameters(‘containerName’))

Following snippet shows actual usage of this function.

"resources": [
{
"name": "[parameters('storageAccountName')]",
"type": "Microsoft.Storage/storageAccounts",
"apiVersion": "[variables('storageAccountApiVersion')]",
"location": "[parameters('location')]",
"properties": {
"accessTier": "[parameters('accessTier')]",
"supportsHttpsTrafficOnly": "[parameters('supportsHttpsTrafficOnly')]"
},
"dependsOn": [],
"sku": {
"name": "[parameters('accountType')]"
},
"kind": "BlobStorage",
"resources": [
{
"name": "[concat('default/', rt.containerNameWithLocation(parameters('containerName')))]",
"type": "blobServices/containers",
"apiVersion": "[variables('storageAccountApiVersion')]",
"dependsOn": [
"[parameters('storageAccountName')]"
]
}
]
}
],

 

So enjoy writing custom functions in ARM Template 🙂

msbuild copy

Copy directory recursively task in MSBuild

So I ran into a situation where I needed to copy a directory to a specific destination through MSBuild.

This is how I could achieve my goal.

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<ItemGroup>
<CloudArtifacts Include=".Cloud\Data\**\*.*"/>
</ItemGroup>
<Target Name="CopyFiles">
<Copy SourceFiles="@(CloudArtifacts)" DestinationFiles="@(CloudArtifacts->'c:\PackableFiles\%(RecursiveDir)%(Filename)%(Extension)')" />
</Target>
</Project>

We can get more details on MS Build Copy task in this link. 

🙂

Create Service Principal using Powershell and Login to Azure with Powershell

What is Service principle?

Service principle are non-interactive Azure accounts.  Applications use Azure services should always have restricted permissions.  Azure offers Service principals allow applications to login with restricted permission Instead having full privilege in non-interactive way.

Using Service Principal we can control which resources can be accessed.

For Security reason, it’s always recommended to use service principal with automated tools rather than allowing them to log in with user identity

Create a Service Principal with PowerShell. 

Note: For this demo we are using Azure RM PowerShell module. Azure has introduced new PowerShell module called AZ. Create AD App

Create AD app

#Create Service principal
New-AzureRmADServicePrincipal ApplicationId $app.ApplicationId `
DisplayName $dummyUrl `
Password $securePassword `
Scope "/subscriptions/<SUBSCRIPTION ID>" `
Role Contributor `
StartDate ([datetime]::Now) `
EndDate $([datetime]::now.AddYears(1)) Verbose

Create a Service Principal

#Create Service principal
New-AzureRmADServicePrincipal ApplicationId $app.ApplicationId `
DisplayName $dummyUrl `
Password $securePassword `
Scope "/subscriptions/<SUBSCRIPTION ID>" `
Role Contributor `
StartDate ([datetime]::Now) `
EndDate $([datetime]::now.AddYears(1)) Verbose

This service principal is valid for one year from the created date and it has Contributor Role assigned. Further using this Service principal application can access resource under given subscription.  We can scope to resources as we wish by passing resource id as a parameter for Scope.

View created AD app in Portal

   1. Log in Portal

  • Go to Azure Active Direcoty -> App Registrations
  • We can find the created app as below
  • Once we click the app we will see app details as below

We need this information when we need to login through Service principal

Login using Service Principal with Powershell

#Login with service principal
$clientId = "<CLIENT ID>"
$credentials = New-Object System.Management.Automation.PSCredential ($clientId, $securePassword)
LoginAzureRmAccount ServicePrincipal TenantId "<TENANTID>" `
SubscriptionId "<SUBSCRIPTIONID>" `
Credential $credentials

Fill out the required parameters.

Once we run the script we can successfully log in to Azure using Service Principal

Full code: 🙂

#Create AD app
$dummyUrl = "https://dummy.dummy.com"
$passpowrd = "Qwerty@123!"
$securePassword = ConvertTo-SecureString String $passpowrd AsPlainText Force
$app = New-AzureRmADApplication DisplayName $dummyUrl `
IdentifierUris $dummyUrl `
HomePage $dummyUrl `
Password $securePassword Verbose
#Create Service principal
New-AzureRmADServicePrincipal ApplicationId $app.ApplicationId `
DisplayName $dummyUrl `
Password $securePassword `
Scope "/subscriptions/<SUBSCRIPTION ID>" `
Role Contributor `
StartDate ([datetime]::Now) `
EndDate $([datetime]::now.AddYears(1)) Verbose
#Login with service principal
$clientId = "<CLIENT ID>"
$credentials = New-Object System.Management.Automation.PSCredential ($clientId, $securePassword)
LoginAzureRmAccount ServicePrincipal TenantId "<TENANTID>" `
SubscriptionId "<SUBSCRIPTIONID>" `
Credential $credentials

 

 

Powershell Identify whether running on Administrator

In some cases, we need to run some script in administrator mode.

Sometimes we face a situation where we want to know whether the script is running on Administrator mode.

Following script says whether PowerShell script is running on Administrator mode or not.


$elevated = [bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).groups -match "S-1-5-32-544")
if($elevated -eq $false)
{
throw "In order to install services, please run this script elevated."
}
else {
Write-Host "You are in Administrator mode"
}

🙂

Calling POST REST API in powershell with headers

In some cases we need to call POST REST API using Powershell.

Let’s go through sample code to get to know how it is done using Powershell.

In this Article we will go through below topics.

  • Create sample Web API
  • Invoke Web API in Powershell

Create Sample Web API

  1. Create ASP.NET Core Web Application

  1. Select API option

  1. Once project created we can see default values controller as below

We need our API to accept some Data. So we will create Modal class for that

  1. Create Modals Folder

  1. Create SampleData class under Modals Folder

  1. Add Sample properties to the class. I created Value1 and Value2 as string type.

  1. Implement API method in ValuesController as below.
[Route(“TestMethod”)]
[HttpPost]
public ActionResult TestMethod(SampleData data)
{
// Do what ever with Data
var authKey = Request.Headers[“AuthKey”];return Ok();

}

Invoke Web API in Powershell

  1. Open Powershell ISE and write following codes to invoke REST API.

 

  • Api url
$apiUri = “https://localhost:44326/api/values/TestMethod&#8221;
  • POST Body Data Object

 

$data = @{
‘Value1’ = “val1”
‘Value2’ = “val2”
}
  • Convert POST BODY data to json format
$requestBody = $data | ConvertTo-Json -Compress
  • Create request headers object
$requestHeaders = @{‘AuthKey’ = ‘sampleauth’}
  • Use Powershell Invoke-RestMethod with parameter as below
Invoke-RestMethod -Method Post -Uri $apiUri -Body $requestBody -ContentType “application/json” -Headers $requestHeaders
  1. Put break point on TestMethod and Run the API project in debug mode
  2. Run the Powershell snippet in Powershell ISE

  1. Breakpoint will be hit and we can see the data we passed.

  1. Once you step over to “authkey” line we can see “AuthKey” header value

 

So this is how we call POST REST API end point in Powershell. ☺

Connect Sitecore 9 instance in Sitecore Rocks

We have found our self needing to connect Sitecore Rocks to Sitecore 9 instance.

When we try to connect to Sitecore 9 instance in Sitecore Rocks in the first time we can not connect.

In order to make it work we have to tweak web.config with following entry to system.web xml node.

<location path="sitecore/shell/WebService">
<system.web>
<authorization>
<allow users="?,*" />
</authorization>
</system.web>
</location>

view raw
tweak.xml
hosted with ❤ by GitHub

🙂

 

Reading json file and update json file in powershell

There are some cases we need to update json files using powershell.

This is how I do it.

$filePath = "C:\jeevan\sample.json"
$file = ([System.IO.File]::ReadAllText($filePath) | ConvertFrom-Json)
Write-Host $file.property1
$file.property1 = Get-Random
$file | ConvertTo-Json | Out-File FilePath $filePath Encoding utf8 Force

view raw
readwritejson.ps1
hosted with ❤ by GitHub

1

I used following json file

{
"property1": 123,
"property2": "value2"
}

view raw
sample.json
hosted with ❤ by GitHub

Done 🙂

 

 

Double tap to exit in xamarin Android

So I had to implement double tap to exit from app in Android using xamarin. This how it is implemented

  • Create blank Android App

create project

 

  • Override OnBackPressed method in MainActivity.cs
private bool doubleBackToExitPressedOnce = false;
public override void OnBackPressed()
{
if (doubleBackToExitPressedOnce)
{
base.OnBackPressed();
Java.Lang.JavaSystem.Exit(0);
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.MakeText(this, "Double tap to exit", ToastLength.Short).Show();
new Handler().PostDelayed(() =>
{
doubleBackToExitPressedOnce = false;
}, 2000);
}

view raw
MainActivity.cs
hosted with ❤ by GitHub

  • That’s it 🙂 Run the app and see the out put

double tap to exit

GIF_Maker_VideoToGif_15-3-2018_95808_PM

Thanks. 🙂

 

Toast in android using xamarin forms

 

When we want to let user know that something happening we can use Toast.

Let’s see how to create Toast in in Android in Xamarin Forms

Create xamrin foms application with Android project

project

  • In .net standard project add a Interface
public interface IToastMessageService
{
void ShowToastMessage(string message);
}

  • In Android project add ToastMessageService and implement the IToastMessageService
[assembly: Xamarin.Forms.Dependency(typeof(ToastMessageService))]
namespace ToastTestXamarin.Droid
{
public class ToastMessageService : IToastMessageService
{
public void ShowToastMessage(string message)
{
Toast.MakeText(Android.App.Application.Context, message, ToastLength.Long).Show();
}
}
}

  • In MainPage.xaml add a button
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:ToastTestXamarin"
x:Class="ToastTestXamarin.MainPage">
<Button x:Name="BtnToastMessage" Text="Show Toast" Clicked="ShowToast"></Button>
</ContentPage>

view raw
MainPage.xaml
hosted with ❤ by GitHub

  • And in the code behind implement the event handler
private void ShowToast(Object sender, EventArgs args)
{
DependencyService.Get<IToastMessageService>().ShowToastMessage("Test Toast Message");
}

view raw
MainPage.xaml.cs
hosted with ❤ by GitHub

Finally run the project 🙂

 

toast

Get the sample project on Github

Download blob as a file in Angular

Recently I got a requirement to download base64 string as .pfx file in Angular application.

So I did that using Blob API in javascript.

More about Blob

So I did a sample application on stackblitz using Angular.

const data = 'some text';
const blob =new Blob([data],{type:'application/octet-stream'});
this.fileUrl =this.sanitizer.bypassSecurityTrustResourceUrl(window.URL.createObjectURL(blob));

As above we need to create Blob object. As second parameter we need to specify Mime type. And in Angular to make the Blob url safe in DOM we can use DomSanitizer.

We have to import DomSanitizer

import { DomSanitizer } from '@angular/platform-browser';</div>
// constructor
constructor(private sanitizer: DomSanitizer) { }

In html template

<a>DownloadFile</a>

Working sample on stackblitz

🙂