Download Blob as file in Javascript

August 2, 2019 jeevan2 Comments

While we are working with Javascript we may find our self in a situation where we need to let users download blob as File.

So In this post, I’ll share basic javascript function which allows us to download blob as a file in the browser.


const downloadBlobAsFile = function(data, filename){
				const contentType = 'application/octet-stream';
        if(!data) {
            console.error(' No data')
            return;
        }

        if(!filename) filename = 'filetodonwload.txt'

        if(typeof data === "object"){
            data = JSON.stringify(data, undefined, 4)
        }

        var blob = new Blob([data], {type: contentType}),
            e    = document.createEvent('MouseEvents'),
            a    = document.createElement('a')

        a.download = filename
        a.href = window.URL.createObjectURL(blob)
        a.dataset.downloadurl =  [contentType, a.download, a.href].join(':')
        e.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null)
        a.dispatchEvent(e)
    }
    
    // call the function 
    const data = "some data";
    const fileName = "filetodonwload.txt";
    downloadBlobAsFile(data, fileName);

You can find a working sample here.

🙂

Deploy storage account and output connection string with SAS token using ARM template

July 29, 2019 jeevan1 Comment

I found my self in a situation where I needed to deploy Azure storage account with a blob container and generate connection string with SAS token and update one of the web app’s settings with generated connection strings.

For this purpose, I used linked ARM template and created Storage account and blob container and generated the connection string with SAS token and output from that template so that master template can use this value.

Table of content

Craft arm template

We need to Craft ARM template as below for our requirement.

	{
	"$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
	"contentVersion": "1.0.0.0",
	"variables": {
	"storageAccountApiVersion": "2018-07-01",
	"storageAccountNameTidy": "[toLower(trim(parameters('storageAccountName')))]",
	"blobEndPoint":"[concat('https://',variables('storageAccountNameTidy'),'.blob.core.windows.net/')]"
	},
	"parameters": {
	"location": {
	"type": "string",
	"defaultValue": "southeastasia"
	},
	"storageAccountName": {
	"type": "string",
	"defaultValue": "awesomestorage"
	},
	"accountType": {
	"type": "string",
	"defaultValue": "Standard_LRS"
	},
	"accessTier": {
	"type": "string",
	"defaultValue": "Hot"
	},
	"supportsHttpsTrafficOnly": {
	"type": "bool",
	"defaultValue": true
	},
	"sasTokenExpiry": {
	"type": "string",
	"defaultValue": "2020-12-31T23:59:00Z"
	},
	"containerName": {
	"type": "string",
	"defaultValue": "test"
	},
	"accountSasProperties": {
	"type": "object",
	"defaultValue": {
	"signedServices": "b",
	"signedPermission": "rl",
	"signedResourceTypes": "sco",
	"keyToSign": "key2",
	"signedExpiry": "[parameters('sasTokenExpiry')]"
	}
	}
	},
	"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/', parameters('containerName'))]",
	"type": "blobServices/containers",
	"apiVersion": "[variables('storageAccountApiVersion')]",
	"dependsOn": [
	"[parameters('storageAccountName')]"
	]
	}
	]
	}
	],
	"outputs": {
	"storageAccountConnectionString": {
	"type": "string",
	"value": "[concat('DefaultEndpointsProtocol=https;AccountName=', variables('storageAccountNameTidy'), ';AccountKey=', listKeys(resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountNameTidy')), variables('storageAccountApiVersion')).keys[0].value)]"
	},
	"storageAccountConnectionStringWithSAS": {
	"type": "string",
	"value": "[concat('BlobEndpoint=',variables('blobEndPoint'),';SharedAccessSignature=', listAccountSas(variables('storageAccountNameTidy'), variables('storageAccountApiVersion'), parameters('accountSasProperties')).accountSasToken)]"
	}
	}
	}

view raw

storage-account-out-connectionstring-withSAS.json

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generate connection string with sas token

As per the above full ARM Template, we can see connection string is generated with full access and another is generated with SAS token.

In order to generate a connection string with SAS token, I have used listAccountSas ARM function.

Find More details on this function here

"storageAccountConnectionStringWithSAS": { "type": "string", "value": "[concat('BlobEndpoint=',variables('blobEndPoint'),';SharedAccessSignature=', listAccountSas(variables('storageAccountNameTidy'), variables('storageAccountApiVersion'), parameters('accountSasProperties')).accountSasToken)]" }

We need to pass three parameters for this function

resourceIdenifier

The name of the storage account within the specified resource group

apiVersion

The API version to use for this operation

requestParameters

We need to pass parameters as specified here

"accountSasProperties": {
            "type": "object",
            "defaultValue": {
                "signedServices": "b",
                "signedPermission": "rl",
                "signedResourceTypes": "sco",
                "keyToSign": "key2",
                "signedExpiry": "[parameters('sasTokenExpiry')]"
            }
        }

We can find more details about parameters specified herein above Microsoft documentation.

Generate connection string with storage account key

We can generate connection string which has full access to storage account with Storage account access keys. We can use listKeys ARM function for this.

We can find more details on this function here.

We need to pass two parameters for this function

Storage account resource id
API version

This function gives you all keys in the storage account and we can select one key to create connection string as below.


listKeys(resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountNameTidy')), variables('storageAccountApiVersion')).keys[0].value

Deploy ARM template

We can use the following PowerShell script to deploy ARM template.

Note: Fill out the required parameters. (denotes in caipatal)


$password = "SECRET"
$clientId = "CLIENTID"
$securePassword = ConvertTo-SecureString $password -AsPlainText -Force
$credentials = New-Object System.Management.Automation.PSCredential ($clientId, $securePassword)
Login-AzureRmAccount -ServicePrincipal -TenantId "TENANTID" -SubscriptionId "SUBSCRIPTIONID" -Credential $credentials 


$templateFilePath = "ARM TEMPLATE PATH"

$resourceGroupName = "RESOURCEGROUPNAME"
$resourceGroupLocation = "LOCATION"
$deploymentName = "DEPLOYMENTNAME"

#Create or check for existing resource group
$resourceGroup = Get-AzureRmResourceGroup -Name $resourceGroupName -ErrorAction SilentlyContinue
if(!$resourceGroup)
{
    Write-Host "Resource group '$resourceGroupName' does not exist. To create a new resource group, please enter a location.";
    if(!$resourceGroupLocation) {
        $resourceGroupLocation = Read-Host "resourceGroupLocation";
    }
    Write-Host "Creating resource group '$resourceGroupName' in location '$resourceGroupLocation'";
    New-AzureRmResourceGroup -Name $resourceGroupName -Location $resourceGroupLocation
}
else{
    Write-Host "Using existing resource group '$resourceGroupName'";
}


# Start the deployment
Write-Host "Starting deployment...";
New-AzureRmResourceGroupDeployment -ResourceGroupName $resourceGroupName -Name $deploymentName -TemplateFile $templateFilePath;

We can see the following output once deployment is successful.

So this is how we deploy storage account and generate connection strings. 🙂

Custom functions in Azure ARM Templates

July 29, 2019July 29, 2019 jeevanLeave a comment

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"
	}
	}
	}

view raw

arm-template-function.json

hosted with ❤ by GitHub

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')]"
	]
	}
	]
	}
	],

view raw

arm-custom-function-usage.json

hosted with ❤ by GitHub

So enjoy writing custom functions in ARM Template 🙂

Copy directory recursively task in MSBuild

July 25, 2019July 25, 2019 jeevan1 Comment

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>

view raw copy-direcotry-recursive-msbuild.xml hosted with ❤ by GitHub

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

🙂

Create Service Principal using Powershell and Login to Azure with Powershell

July 15, 2019July 25, 2019 jeevanLeave a comment

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

view raw CreateServicePrincipal.ps1 hosted with ❤ by GitHub

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

view raw CreateServicePrincipal.ps1 hosted with ❤ by GitHub

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 with service principal

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

view raw LoginWithServicePrincipal.ps1 hosted with ❤ by GitHub

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)
	Login-AzureRmAccount -ServicePrincipal -TenantId "<TENANTID>" `
	-SubscriptionId "<SUBSCRIPTIONID>" `
	-Credential $credentials

view raw ServicePrinciplePowershell.ps1 hosted with ❤ by GitHub

Powershell Identify whether running on Administrator

March 8, 2019 jeevanLeave a comment

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

November 13, 2018January 21, 2019 jeevanLeave a comment

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

Create ASP.NET Core Web Application

Select API option

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

Create Modals Folder

Create SampleData class under Modals Folder

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

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

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

Api url

$apiUri = “https://localhost:44326/api/values/TestMethod”

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

Put break point on TestMethod and Run the API project in debug mode
Run the Powershell snippet in Powershell ISE

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

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

August 19, 2018 jeevanLeave a comment

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

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🙂

Reading json file and update json file in powershell

March 17, 2018 jeevanLeave a comment

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

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I used following json file

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

view raw

sample.json

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Done 🙂

Double tap to exit in xamarin Android

March 15, 2018 jeevan3 Comments

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

Create blank Android App

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

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

Thanks. 🙂

randomtutes

.NET, SQL Server , WEB, Angular, Powershell, Azure

Author: jeevan