C#

Automate Retrieving Azure VM Data Using Azure Resource Graph (ARG) and C#

Mihai AlbertLeave a comment

In this post, we’ll look into using Azure Functions to run C# code. We’ll keep things simple, and we’ll only use a timer-based function. The function itself will simply write output data to a storage account, as a simple JSON file. The payload is something we’ve looked at before in detail: the list of all Azure VMs with all their private and public IPs.

Why go over the same thing that was discussed previously? First, we’ve used several methods to gather the data in that post (Powershell, Azure Resource Graph Explorer (ARGE), Azure CLI) but neither involved C#. Secondly, the methods depicted weren’t automation-ready, in the sense that one would still have to perform things manually to get the results (for Powershell, run the script; for Azure CLI, run the commands; for ARGE, run the query and manually export the results).

This time, C# code within an Azure Function will automatically write our output .json file, without any sort of manual intervention, via a timer-based trigger. The underlying technology to get all the networking data for the Azure VMs will be Azure Resource Graph (ARG).

Continue reading →

Get the List of All AWS EC2 Instances With All Their Private and Public IPs

Mihai Albert2 Comments

You want to retrieve a list of all your AWS EC2 instances, complete with all their private and public IPs. You want to do this across your whole AWS organization, thereby targeting all the AWS accounts and all the regions enabled for each. And you’d also want to use C# for the job.

This post will detail how to do this, starting from explaining the base concepts and going all the way to building the code. The output – alongside basic console text – will consist of a .json file containing the following attributes for each EC2 instance:

  • Instance id
  • Instance type
  • All private IP addresses
  • All public IP addresses
  • Parent AWS account name
  • Parent AWS account id

If you’d like to skip directly to the C# code for retrieving private and public IP addresses for all EC2 instances using IAM users, go here. For the C# code that uses SSO users, go here.

Continue reading →

Use Microsoft Graph to Retrieve Users Photos and Store Them as Azure Blobs With C#

Mihai Albert2 Comments

A strange request comes your way. The photos of everyone in your organization’s Office 365 tenant need to be provided as .jpg files. They have to be imported into a proprietary app, and named based on an attribute that uniquely identifies to whom each belongs. It’s not clear yet if they just want all the photos as a giant .zip archive, or if their app runs in Azure and needs the photos stored in a storage account. You come across the Get-UserPhoto Powershell cmdlet, which seems to offer a quick solution, but it fails to deliver against those users that still have their mailbox on-premises. How to go about it?

TL;DR The sample code that retrieves photos from Office 365 and stores them both locally on disk, as well as in Azure Blob storage, can be found here.

The main goal of this post is to get users’ pictures from an Office 365 tenant. We’ll subsequently store them in 2 places: on disk and in an Azure storage account as block blobs. We’ll only target ‘live’ users, meaning those that have their account enabled and also have an employeeNumber. Our scenario further detailed:

Continue reading →

Using Microsoft Graph to Modify Excel Files Stored in Sharepoint Online With C#

Mihai Albert1 Comment

You just want to modify the content of a few cells in an Excel file stored in Sharepoint Online, using C#. A simple goal. Maybe your experience with Sharepoint APIs is fairly limited, so you spend a while researching. There’s questions over at Stack Overflow, that mention “CSOM”, “REST APIs”, “Graph” and various other cryptic terms, but aside the various limitations with each API, a concise and clear sample proves to be elusive.

TL;DR If you’re in a hurry to get to the sample code, skip right to it.

The goal of this post is to use Microsoft Graph to read and write to an Excel file stored in Sharepoint Online. As the main focus is getting to use Graph against Sharepoint Online just to get to an Excel file, in terms of operating against the file itself we’ll be content with just reading and updating the value of a single cell.

Continue reading →

List vs ArrayList in Azure Functions

Mihai AlbertLeave a comment

You’re using Azure Functions, and need to decide on the types to use in your C# code in order to implement whatever you’re trying to achieve. In today’s world of powerful cloud computing with sometimes cheap or downright free resources, is it worth pondering over the best type to use ? After all, you get 400,000 GB-s for free per month as part of the consumption plan. And the code within this Azure Function will be just a few dozen lines, tops. Would it matter selecting an efficient data structure for your implementation ?

Let’s get specific. Say storing 10 mil numbers is needed each minute as an interim step for further processing. Do you go with ArrayList or List<int> ? Your 2 options below:

Figure 1 – Function execution units for both the ArrayList and the List<int> functions against 10 mil elements, running once each minute

Oh, and you get to pay for the area under the graph of each function. How much does that come to ? Read on.

Continue reading →