One more article before Christmas! 😁 This time, I’ll be fixing a function that’s triggering based on new messages received through my IoT Hub in my Azure Functions project. Technically speaking, this is super simple to implement – your function needs to define an IoTHubTrigger, with an Event Hub name and usually a Connection String (I don’t know why I’m Sentence Casing that, too, but I’ll stick to it!) You can tap a practically unlimited number of Azure Function triggers to any Event Hubs (or…Continue reading How to fix “Microsoft.WindowsAzure.Storage: Server encountered an internal error. Please try again after some time.” when using IoTHub trigger for Azure Functions?
Another fun one with Azure Functions! At least it’s a simple one: this time, I ran into a weird issue while doing some code reusing – well, copy-pasting – between a couple of different projects. I was lovingly hand-crafting some Azure Functions, while suddenly the Azure Functions host would throw me this in ugly, red letters: Mono.Cecil.AssemblyResolutionException: Failed to resolve assembly: ‘Microsoft.AspNetCore.Mvc.Core, Version=126.96.36.199, Culture=neutral, PublicKeyToken=adb9793829ddae60’ at Mono.Cecil.BaseAssemblyResolver.Resolve(AssemblyNameReference name, ReaderParameters parameters) at Mono.Cecil.BaseAssemblyResolver.Resolve(AssemblyNameReference name) at Mono.Cecil.DefaultAssemblyResolver.Resolve(AssemblyNameReference name) at Mono.Cecil.MetadataResolver.Resolve(TypeReference type) at Mono.Cecil.ModuleDefinition.Resolve(TypeReference type) at Mono.Cecil.TypeReference.Resolve() at…Continue reading Azure Function build fails with “Mono.Cecil.AssemblyResolutionException: Failed to resolve assembly: Microsoft.AspNetCore.Mvc.Core”
This article explains how to fix an issue where your Azure Functions function (yes, that’s a capital F and a lowercase f to denote the difference between the product and the piece of compute) fails to fire when a POST request comes in, even though it’s configured to do so, and instead throws a somewhat confusing error message about HttpRequestMessage not being castable to HttpRequest – even though you KNOW HttpRequestMessage works just fine for receiving POST requests with payload! So, why is this happening…Continue reading How to fix “Unable to cast object of type ‘System.Net.Http.HttpRequestMessage’ to type ‘Microsoft.AspNetCore.Http.HttpRequest’.”
This article explains another fun issue you might run into, when developing Azure Functions in your local environment. It was weird how unclear the few results I could find were, and the issue is just… Very hazy in general. But I was able to track the issue down, and thought I’d document the solution :) It’s for myself, really, because I’m pretty sure I’ll run into this one again. But if you find it useful, good for you! 😉 Problem So what is it, that’s…Continue reading ILogger binding suddely failing for Azure Functions – what to do?
This article aims to patch one annoying gap in Microsoft’s documentation: how, exactly, do you update Azure Function App’s application settings using an Azure DevOps build/release pipeline? It sounds easy, and like something that should happen almost automatically – and for Azure Web Apps (or App Services, as they are often called) it IS practically automatic. But for Azure Functions, it isn’t. And the docs aren’t perfect. Let me try and fix that. Problem Azure Functions won’t take your appsettings.json file, “mapping” your variable groups…Continue reading How to update application settings of an Azure Functions App in Azure DevOps Pipeline
Another day, another issue with Azure Functions! For such a simple and powerful tool, it sure does produce a lot of topics for blog articles! 😁 So let’s get down to fixing another Azure Functions configuration issue. But wait – what WAS the problem again? Problem When firing up your Azure Functions project locally, this error is what you’re confronted with: “Missing value for AzureWebJobsStorage in local.settings.json. This is required for all triggers other than httptrigger, kafkatrigger. You can run ‘func azure functionapp fetch-app-settings ‘…Continue reading How to fix “Missing value for AzureWebJobsStorage in local.settings.json” when you’re debugging Azure Functions locally?
Sometimes, you need to change the hosting model (or tier) for your resources on Azure. Maybe you’ve outgrown whatever you’ve originally selected, maybe you’ve got too much cash on your hands, or maybe you’re like me, and you get absolutely and completely fed up with the cold starts for your Azure Function apps on Consumption plan. For these situations, you have the possibility of changing the hosting tier – the plan – you’re on. Although, this has been implemented in a disturbingly non-intuitive way! You’ll…Continue reading How to upgrade your Azure Function app plan when you originally selected “Consumption”?
Well, that title is a mouthful. But it’s the topic for today, so what can you do? That said, this article should be pretty topical, as the issue started popping up only a few days ago. Chances are it’ll be patched soon enough, but in the meantime, it’s always useful to document the fix! Problem When running or debugging Azure Functions locally, your runtime just blurts our this error and fails to compile your functions: [2021-01-11T10:28:11.495Z] A host error has occurred during startup operation ‘0d00defa-b8bd-4fb8-9794-b0e5950a4c38’.…Continue reading How to fix “System.IO.FileSystem: Could not find a part of the path \AppData\Local\AzureFunctionsTools\Releases\3.17.0\workers. Value cannot be null. (Parameter ‘provider’)” when running Azure Functions locally?
Ah, one more on the related topics of different configurations for your Azure Function apps. In this article, I will describe how you can configure the Entity Framework Core database context to be injected into your Azure Functions App. In my experience, this is a very typical and often-needed model to structure your Azure Functions. Therefore, while tooling and templates aren’t quite there, it’s worthwhile to document how to do this somewhere – well, here. Solution I’ve posted before about how to instantiate a database…Continue reading How to inject EF Core DbContext in an Azure Function
Azure Functions use dependency injection, and that allows us to define all kinds of prebuilt or custom-built services as being available for our functions really easily. This is a really easy way to initialize scoped resources to be used in your different functions… But how do you actually configure them in an Azure Functions App? Problem Okay, a step back – there’s a bit of a problem that we need to resolve before we can proceed with the configuration. When you create a new Azure…Continue reading How to configure Azure Function’s startup
Hah – another interesting one. This article describes how to resolve an error along the lines of “Microsoft.Data.SqlClient: Microsoft.Data.SqlClient is not supported on this platform.“, thrown by Azure Functions host. Apparently you can run into this issue either on your local development machine or even in Azure. Problem For me, this error popped up after some house cleaning tasks – dependency updates, merging feature branches… You know the stuff. And suddenly, while the Azure Function App would build and run just fine, my SQL calls…Continue reading How to resolve “Microsoft.Data.SqlClient is not supported on this platform.” in an Azure Function App?
This article describes a solution to an error “Insufficient memory to continue the execution of the program.” I was debugging an Azure Function locally and ran into it – it stopped my Azure Function from starting at all. So, this is what I got: Insufficient memory to continue the execution of the program. Ohh… kay..? My development machines have plenty of RAM, surely enough to run an Azure Function! Hell, I’m sure I have enough memory to have Google Chrome running while debugging a pesky…Continue reading How to resolve error “Insufficient memory to continue the execution of the program.” when debugging Azure Functions locally?
So, another interesting issue I ran into when developing Azure Functions locally. What an endless bag of funsies! 😁 This time, the issue was simple but infuriating – my Azure Functions host would just silently close when debugging: none of the breakpoints would be hit, no information would be logged anywhere. Azure Functions Core Tools (2.4.432 Commit hash: 3371a87e0fce2aa35986c0de8e77d5d618163b91) Function Runtime Version: 2.0.12332.0 The system cannot find the file specified Press any key to continue . . . I first encountered this by the Azure…Continue reading Azure Functions host quits with “The system cannot find the file specified”
I dont’ know about you, but it’s happened to me a few times: fire up your Azure functions project, hit F5 to start debugging, project builds without errors, Azure Functions host starts… And shuts down right away. This article has a few quick and simple tips on how to extract a bit more information from Azure Functions host (func.exe), when it’s just silently failing. This means by default you won’t get any information about what’s going wrong. However, a couple of steps should get you…Continue reading How to extract more information out of your Azure Functions host failing silently?
This post describes how you can easily enable debug/verbose information for your Azure Functions for a lightweight and built-in way to extract just a bit more information out of your Azure Function executions. There’s different methods available for Azure and your local development environment. Problem Azure Functions are awesome. But by default, your tools on gathering information without some additional configuration are not that great. The “monitor” view of the function doesn’t give you more than an excerpt of the console. This applies not only…Continue reading How to enable verbose logging for Azure Functions?
This post describes how you can access your Entity Framework Core model classes and the database context in your Azure Functions. In my example I’m using EF Core 2.1, but the main principle should be the same for later versions as well. Please note, that I use Azure functions runtime v2 (but it should work the same in v3 !) Another easy one, that I was unable to find much guidance on! But first, let’s start with the basics. Why would you want to have…Continue reading How to access Entity Framework Core’s DbContext in an Azure Function?
Welp – another interesting error encountered while deploying Azure Functions to Azure. So, everything runs nicely locally, but when you deploy your well-tested, functional and pretty code to run them in the cloud, you’ll just get these ugly and unfriendly errors. Long story short, “Function compilation error” is what you’re faced with. Example error below: Function compilation error Microsoft.CodeAnalysis.Scripting.CompilationErrorException : Script compilation failed. at async Microsoft.Azure.WebJobs.Script.Description.DotNetFunctionInvoker.CreateFunctionTarget(CancellationToken cancellationToken) at C:\azure-webjobs-sdk-script\src\WebJobs.Script\Description\DotNet\DotNetFunctionInvoker.cs : 314 at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at async Microsoft.Azure.WebJobs.Script.Description.FunctionLoader`1.GetFunctionTargetAsync[T](Int32 attemptCount) at C:\azure-webjobs-sdk-script\src\WebJobs.Script\Description\FunctionLoader.cs : 55 at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at async…Continue reading Sudden “Function compilation error” for an Azure Function
Have you ever run into a situation, where you just wanted to remove the currently standing function definitions from your app service without actually nuking the whole Functions app? I have! App Service configuration is usually easy to manage programmatically or by scripting, so even if you need to redo the deployment, it should be fairly straightforward. But what if you don’t have the setup scripted, and have already configured everything the way you like it – you’d really like to NOT nuke the whole…Continue reading How to remove Azure Functions without deleting the Functions App?
I recently ran into an issue when developing Azure Functions locally. My SPFx webpart was configured to request information from my locally running Azure Function, but suddenly started ending up in error. Browser only showed 404 for the first request (OPTIONS) the SPFx webpart was sending – although I knew the function was up and running! So what to do? Posts Related to “Azure Functions failing on “OPTIONS” call? Quick fix!”:How to get application settings for your Azure Function App using C#?How to fix an…Continue reading Azure Functions failing on “OPTIONS” call? Quick fix!
Ignite 2018 is done and dusted, and it’s a good time to quickly recap what’s new for Azure Functions in the coming months. They’ve certainly been getting a lot of love from Microsoft, which is GREAT! New features for Azure Functions There was a bunch of exciting new things announced! Not all of the things in this blog post are necessarily completely new – but rather reached General Availability. Let’s go through them one by one… Posts Related to “Ignite 2018 recap: What’s new for…Continue reading Ignite 2018 recap: What’s new for Azure Functions?