How to use azure feature flag in asp.net core Blazor

[danroth27]

From @ajai1109 on Friday, October 25, 2019 12:30:26 PM

How to use azure feature flag in asp.net core Blazor

Copied from original issue: aspnet/AspNetCore#15592

[danroth27]

From @javiercn on Monday, October 28, 2019 8:49:51 AM

@ajai1109 thanks for contacting us.

Can you provide a bit more details on what you are trying to achieve? We're not sure what "azure feature flag" means in this context.

[danroth27]

From @ajai1109 on Monday, October 28, 2019 1:46:04 PM

I am trying to implement azure feature flags in asp.net core blazor project. Please go through this link https://docs.microsoft.com/en-us/azure/azure-app-configuration/quickstart-feature-flag-aspnet-core for your reference

[danroth27]

From @javiercn on Monday, October 28, 2019 1:57:23 PM

@ajai1109 There's no specific support on Blazor to do that, and that's not something that the ASP.NET Core team works on.

@bradygaster Can you loop in the right people here so that we can provide guidance or improve the experience for Blazor users?

To get a faster response we suggest posting your questions to StackOverflow using the asp.net-core-blazor tag.

[ajai1109]

Is there any documentation to implement azure feature flags in asp.net core blazor application.

[danroth27]

@yegu-ms

[zhenlan]

@ajai1109 good question. This is an area we didn't look into feature management support yet.

The Azure App Configuration is mainly targeting server/service scenarios at this point. We are interested to extend it to client scenarios in the future (eg. support millions of concurrent client requests for one config store). Blazor is for client web development. We need to explore how the App Configuration can be useful with Blazor.

Microsoft.FeatureManagement.AspNetCore as a feature management framework for ASP.NET Core is independent of App Configuration. I think we should definitely look into what support we need to add for Blazor.

[zhenlan]

This is also tracked in https://github.com/microsoft/FeatureManagement-Dotnet/issues/4

[bradygaster]

@danroth27 and rest - apologies, just saw this note. @ajai1109 have you taken a look at this documentation?

https://docs.microsoft.com/en-us/azure/azure-app-configuration/quickstart-feature-flag-aspnet-core

If so, is there a functionality gap you're witnessing with Blazor apps? Or, are you more explicitly asking about client-side Blazor support for Azure Feature Flags and/or Azure App Configuration?

[ajai1109]

@bradygaster I have gone through that document but it is not straight forward to implement Azure-Feature-Flags in Blazor app (server-side). If any document specific to Blazor applications it will be helpful for all those who are planning to implement Azure-Feature-Flags in Blazor app. Thanks!

[robertmclaws]

@bradygaster et al, I'm working to implement Feature Flags in our Blazor WebAssembly port of BurnRate.io. Are there any docs specifically for this yet? I saw the Server-Side version here (thanks Brady!), but it isn't entirely clear how to call .ConfigureAppConfiguration() in a client-side scenario, and it's not clear that this issue has been resolved either.

Any insights you could provide would be awesome. Thanks so much!

[jimmyca15]

@robertmclaws

There aren't any docs for using Azure App Configuration feature flags in Blazor. As you mentioned we have a solution laid out and documented for server-side feature flags and configuration but there are still improvements to be made before we can have parity for client-side feature flags.

[robertmclaws]

If you are porting an app from Javascript, then you don't get all the fancy Feature Flag wire-up stuff that you get on the server-side. So I think it's important to manage expectations on both sides.

Honestly, I think this is what most people are looking for right now: https://docs.microsoft.com/en-us/dotnet/api/overview/azure/data.appconfiguration-readme?view=azure-dotnet-preview. Just found the docs for it, and I think pointing people to this library for now is sufficient, given the circumstances.

Thanks!

[jimmyca15]

@robertmclaws

I see, if the SDK suits your needs then that is perfect. One thing I want to call out here though for client-side usage is scalability.

Azure App Configuration has a request quota detailed here. Depending on the scale of the client-side application it is possible to reach limits quickly. Client-side and server side scaling are different in this regard. Server side instances are usually smaller in number and can do better caching. This is one of the areas with room for improvement that I was talking about previously. What we have suggested before to resolve this issue is to host a proxy-like web application that queries App Configuration and caches it for use by client-side applications.

[zhenlan]

Feature flags are supported in server side Blazor apps. Here is an example: https://github.com/microsoft/FeatureManagement-Dotnet/tree/main/examples/BlazorServerApp

@zhiyuanliang-ms, we should have a quickstart document on this topic.