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Develop Azure Functions using .NET Core 3.1

Jeff Hollan on October 17, 2019

<< Updated on Dec 9 2019 with go-live announcement of Azure Functions on .NET Core 3.1 >> We're extremely excited to announce you can ...

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Hamed • Oct 19 '19 • Edited

Hi,
I get these errors in this preview:
Microsoft.Data.SqlClient is not supported on this platform.
System.Drawing is not supported on this platform.

Jakob G. Svendsen • Oct 21 '19

Jeff Hollan • Oct 21 '19 • Edited

Can you let me know the package you are pulling in that is causing this, and how you are using it? Any steps I can take to repro would be great.

Marc • Oct 22 '19

I created an issue on GitHub. I'm getting the same thing. My suspicion is that it's coming from Entity Framework

github.com/Azure/Azure-Functions/i...

Hamed • Oct 22 '19

issue comes from Microsoft.EntityFrameworkCore.SqlServer when calls DB.
System.Drawing also in any call will get error.

Marc • Oct 23 '19

Do you know of a workaround / fix?

Marc • Oct 24 '19

Someone got back to me on my GitHub Issue (github.com/Azure/Azure-Functions/i...) with a workaround that fixes this.

Jakob G. Svendsen • Oct 30 '19

Sorry for not getting back to you earlier" been super busy in ignite planning! Great to see there is a workaround. Will test it ASAP!

Jeff Hollan • Dec 3 '19

Not sure where this landed but as an FYI just tested using both Entity Framework and SQL server on v3 bits and worked fine. Here's my repo: github.com/jeffhollan/functions-ch...

Hamed • Dec 13 '19

3.1 works perfectly. Good job.

John D'Alessandro • Nov 8 '19 • Edited

I'm having trouble building a v3-preview project in my DevOps Git repo CI pipeline. Despite applying all of the upgrade steps you gave it's still looking for a Microsoft.NETCore.App 2.1.0 framework. dotnet build works locally. Deployment also works locally, and I have my function app running just fine, but not having CI/CD is a bottleneck.

Patrick • Nov 18 '19 • Edited

Hi John I'm encountering the same issue. Did you find a solution?

It is compiling and running in my dev environment using .NET Core 3.0 but behind my Azure build Pipeline I get the following error

It was not possible to find any compatible framework version [/home/vsts/work/1/s/blah.csproj]
error : The specified framework 'Microsoft.NETCore.App', version '2.1.0' was not found.
error : - The following frameworks were found: [/home/vsts/work/1/s/blah.csproj]
error : 3.0.0 at [/opt/hostedtoolcache/dotnet/shared/Microsoft.NETCore.App]
error : [/home/vsts/work/1/s/blah.csproj]

Jeff Hollan • Nov 19 '19

Was able to repro. Found a bug. Tracked here: github.com/Azure/azure-functions-v...

workaround is to make sure 2.x is on the build box as well. I changed my deploy script to this and it worked in the interim.

- task: UseDotNet@2
  inputs:
    packageType: 'sdk'
    version: '2.1.x'
- task: UseDotNet@2
  inputs:
    packageType: 'sdk'
    version: '3.0.x'

doogdeb • Nov 6 '19

When trying to pull in a netcore3.0 logging component we've written, it complains with the following.

Error System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified.
File name: 'Microsoft.Extensions.Logging.Abstractions, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'
at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
at System.Reflection.RuntimeMethodInfo.FetchNonReturnParameters()
at System.Reflection.RuntimeMethodInfo.GetParameters()
at MakeFunctionJson.MethodInfoExtensions.GetDisabled(MethodInfo method)
at MakeFunctionJson.MethodInfoExtensions.HasUnsuportedAttributes(MethodInfo method, String& error)
at MakeFunctionJson.FunctionJsonConverter.GenerateFunctions(IEnumerable1 types)+MoveNext() at System.Collections.Generic.List1.AddEnumerable(IEnumerable1 enumerable) at System.Linq.Enumerable.ToList[TSource](IEnumerable1 source)
at MakeFunctionJson.FunctionJsonConverter.TryGenerateFunctionJsons()
at MakeFunctionJson.FunctionJsonConverter.TryRun()

Error generating functions metadata
Logging.UserAgent C:\Users\user.nuget\packages\microsoft.net.sdk.functions\1.0.30-beta2\build\Microsoft.NET.Sdk.Functions.Build.targets 41

Andreas Öhlund • Dec 9 '19

Are there any known issues with app insights when running locally?

Previously I could inject a TelemetryConfiguration into my function but since updating to v3 from the preview it blows up with:

Microsoft.Extensions.DependencyInjection.Abstractions: Unable to resolve service for type 'Microsoft.ApplicationInsights.Extensibility.TelemetryConfiguration'

Not tested if this works when publishing though.

Jeff Hollan • Dec 9 '19

No known issue but I imagine this is due to in conflicting with its own configuration and potentially something changed between versions. I’d open up a GitHub issue for this one

Elias Hdez • Dec 10 '19 • Edited

Overall, dependency injection issues has been since the .NET Core 3.0 release. Can you follow up this please?

github.com/Azure/azure-functions-d...

and this

github.com/Azure/azure-functions-d...

Andreas Öhlund • Dec 10 '19

Thanks, raised github.com/Azure/azure-functions-h... , seems to be more ppl with the same issue.

Andreas Öhlund • Dec 9 '19

Ie this no longer works locally docs.microsoft.com/en-us/azure/azu...

Patrick • Nov 18 '19 • Edited

Hi Jeff,

I have followed your article and my solution is compiling and running in my dev environment using .NET Core 3.0 but behind my Azure build Pipeline I get the following error. Could you please offer any suggestions?

Jeff Hollan • Nov 18 '19

Your app is set to target 2.1 so your build agent will need a 2.x version. Reads that build agent only has 3.x. Other option is change app target is csproj to netcoreapp3.0

Patrick • Nov 19 '19

Hi Jeff thanks heaps for your response it hugely appreciated!

My .csproj file currently contains the following. Would you then expect the Azure build pipeline to target 3.0 and not 2.1?

netcoreapp3.0
v3-preview

Jeff Hollan • Nov 19 '19

Hmm if that’s what your csproj says maybe the problem is the other way around. Can you confirm the devops agent has and is using dotnet 3? I don’t know where the 2.1 would come from if it’s not in your csproj file

Patrick • Nov 19 '19 • Edited

I'm executing a "use .NET Core" step beforehand which is set to version 3.0.x. I noticed John D'Alessandro also posted here with the same issue :(

I also tried setting the Agent Specification to windows-2019 value as suggested here stackoverflow.com/questions/565741...

Jeff Hollan • Nov 19 '19

Ok let me see if I can repro

Jeff Hollan • Nov 19 '19

Was able to repro. Found a bug. Tracked here: github.com/Azure/azure-functions-v...

workaround is to make sure 2.x is on the build box as well. I changed my deploy script to this and it worked in the interim.

- task: UseDotNet@2
  inputs:
    packageType: 'sdk'
    version: '2.1.x'
- task: UseDotNet@2
  inputs:
    packageType: 'sdk'
    version: '3.0.x'

Smartymind • Nov 14 '19 • Edited

Thanks for this updated information about what visual studio must be used. Maybe it is our fault behavior but we was not checking this article everyday so we did not get this notice before we updated visual studio to newest version therefore the development has stopped. Do you have any idea how could we install a specific version of visual studio 2019 community? I've found only links to professional and enterprise versions here.

Colby Tresness • Nov 14 '19

Hey there - we're really sorry that we had to make this change. Unfortunately it was necessary in order to prevent breaking old versions of Visual Studio once we take the experience out of preview. We don't expect it will happen again.

This should help: docs.microsoft.com/en-us/visualstu...

Smartymind • Nov 15 '19

This link did not help.

Vijay • Oct 29 '19

The main issue we have is that it’s incompatible with net standard 2.1.

If function project A exposes a class from net standard project B, when B is 2.0 everything works, when B is 2.1 the solution won’t even compile anymore.

This issue has been blocking since release with no comment from maintainers, are you able to have someone look into it?

Mr Simon C • Oct 19 '19

Came across this post by sheer luck last night - and tried it out. Works great! I can confirm Azure Function v3 with Microsoft Graph Auth works really well. Also really nice to use Null coalescing assignment and in-built Json Serializer. May I never have to hear "Newtonsoft" by choice ever again ;)

sjscheider-tt • Nov 13 '19

I had this working for a couple weeks now. After an OS update, I think that is the culprit, I'm getting the following error when I try to run any functions is Visual Studio.

"There is no Functions runtime available that matches the version specified in the project"

sjscheider-tt • Nov 16 '19

A co-working of mine was able to figure this one out with the assistance of this link:
github.com/Azure/azure-functions-t...

In the file feed.json (C:\Users\[user]\AppData\Local\AzureFunctionsTools\feed.json): it defines all capable versions you can debug in VS.
The feed.json updates automatically and for some reason the information for v3-preview disappeared for both my co-worker and I.

So we just "hardcoded" the executable path under Properties > Debug for the project.
Set the executable to: C:\Users\[user]\AppData\Local\AzureFunctionsTools\Releases\3.0.3\cli\func.exe
Set application arguments to: start

Mark Davies • Nov 19 '19

Cautionary note. I had a working function and re-factored to put one of the function service dependencies in its own .net standard library. It stopped working.

If you get an error like
FunctionApp1: Method not found: 'Microsoft.Extensions.DependencyInjection.IServiceCollection Microsoft.Azure.Functions.Extensions.DependencyInjection.IFunctionsHostBuilder.get_Services()'.
Then you may be missing the crucial step I missed : setting the AzureFunctionsVersion from v2 to v3-preview in the project file. It worked as V2 as a single project function and only stopped working when I separated the injected dependency service into its own library. HTH.

felicss • Dec 3 '19

Did this actually solve the problem for you? I am still getting the same error, even with v3-preview

felicss • Dec 3 '19

Fixed it => the latest preview-release of the Microsoft.EntityFrameworkCore 3.1.0-preview3 seems to cause the problem

smimon • Nov 18 '19

After running "npm install -g azure-functions-core-tools@preview", I do not have version 3 available in the C:\Users[User]\AppData\Local\AzureFunctionsTools\Releases folder - highest version is still 2.42.0

Any ideas how to pull in the preview version? Thanks

smimon • Nov 18 '19

Never mind, I found instructions on how to download it manually from here github.com/Azure/azure-functions-t...

Carlos Mendible • Nov 25 '19

Hi Jeff is there a preview version of the Docker image so I can update my mcr.microsoft.com/azure-functions/dotnet:2.0 refs?

zach pertee • Nov 26 '19

Ditto. I also badly need this feature. Can I simply update my dockerfile to install .net core 3 or is there more to it than that?

Jeff Hollan • Nov 27 '19

We have them published mcr.microsoft.com/azure-functions/...

zach pertee • Nov 27 '19

Thanks Jeff!

Carlos Mendible • Nov 27 '19

Thanks dude!

Chartlog • Nov 23 '19

After spending the entire day to try to get this working I have finally given up. I was in the midst of trying to automate my ef migrations using azure pipelines and ran into an issue where generated migration scripts would have syntactical issues described here

github.com/aspnet/EntityFrameworkC...

This led me to upgrade to ef core 3, which led me down a cascade of events in upgrading my solution to .netcore 3 and .net standard 2.. I will have to resort to manually running migrations on each release :*****(

anskanth • Aug 12 '20

Hey
Wondering if you have any solution/alternates for the problem I posted in here realted to deployment slots.. stackoverflow.com/questions/633845...

It's a bit bigger one but for sure an interesting one :)

abmis-mi • Jun 19 '20

Hi,
I want to add app insights logging to Azure Function v3 as we do in Web Jobs v3 like:
builder.ConfigureLogging((context, logging) =>
{
logging.AddApplicationInsightsWebJobs(o => o.InstrumentationKey = appInsightsKey);
});

I tried similar code there but it didn't work.
builder.Services.AddLogging(builder => {
builder.AddApplicationInsights(appInsightsKey);
});

Is there a documented way of adding app insights to azure functions in code?

David Poulin • Nov 22 '19 • Edited

Hey,

Just a fast feedback on my experience with Azure Functions using net core 3.0
I was feeling quite lazy about installing another preview of visual studio 2019, so i kept using my current version (16.3.8).

My main prerequisite was to install the latest version of the azure function preview tools (i did it on powershell).

How i got using my azure function .net core 3.0 (with net standard library 2.1 ?).

1/ Creating azure function with vs 2019 (non preview)
2/ change in csproj AzureFunctionsVersion from v2 to v3
3/ update Microsoft.NET.Sdk.Functions to 1.0.30-beta2 (the 3.xxx does not work for me).
Each time i tried to debug with vs, i got a crash.
4/ Then, tried to start my project with command lines ( func start --build )
5/ Every thing goes well locally and when deployed to azure

On Azure portal, I only had to activate the runtime preview (v3). nothing else.

As you can not debug with my solution, you will have to use efficiently logging (everyone is supposed to do it right ;p).

Abhishek @ Ace The Cloud • Oct 22 '19

The Git Repository that this Azure Fx package mentioned nuget.org/packages/Microsoft.NET.S...

is not having code related to 1.0.30-beta2 , and neither in Release section of git repo 1.0.30-beta2 is mentioned as Released.

github.com/Azure/azure-functions-v... , in branches there is branch for beta1 but not for beta2 , not sure why it is so ?

Elias Hdez • Dec 10 '19

Overall, dependency injection issues has been since the .NET Core 3.0 release. Can you follow up this please? @jeffhollan

github.com/Azure/azure-functions-d...

and this

github.com/Azure/azure-functions-d...

Kabue Charles • Oct 27 '19

Error generating functions metadata because of Microsoft.AspNetCore.Mvc.Abstractions, Version=3.0.0.0 , see: github.com/Azure/azure-functions-v...

Andrii Maksymets • Oct 18 '19

Can I use F# or do you have templates for it?

Jeff Hollan • Oct 18 '19

Yep! Have a few templates you can install via NuGet and dotnet cli here github.com/Azure/azure-functions-t... or VS Code will list and use if you select to view “All” templates github.com/microsoft/vscode-azuref...

miguelEsteban • Nov 11 '19

Colby Tresness • Nov 14 '19

Update to the latest Visual Studio 2019 preview if you're still having this issue.

Andreas Jakof • Oct 18 '19 • Edited

\o/
Good news, can't wait until .NET Core 3.0 is available everywhere in Azure, without having to install additional extensions.

zpittmansf • Oct 24 '19

I was able to see the preview in the drop down yesterday but today I cannot. I posted an issue on github github.com/Azure/azure-functions-h....

zpittmansf • Nov 15 '19

Another way to get around this is just running the version of func.exe that you want. You can do this by changing the debug settings of the csproj to
C:\Users\xxxx\AppData\Local\AzureFunctionsTools\Releases\3.0.2\cli\func.exe and a parameter of start.

Colby Tresness • Nov 14 '19

Update to the latest Visual Studio 2019 preview if you're still having this issue.

zpittmansf • Nov 15 '19

Thanks, I am not but hopefully they fix this mapping problem of versions before it gets out of preview ;)

jagge123 • Nov 13 '19

Did all the steps above and still no sign of Azure Functions v3 Preview - option in the drop down. Any ideas?

Colby Tresness • Nov 14 '19

You're likely not on the latest VS 2019 Preview. What version are you using?