Azure Functions - using appsettings.json

Question

Is it possible to use an appsettings.json file in Azure Functions?

There is documentation for environment variables here..

https://docs.microsoft.com/en-us/a

Answer 1

According to the changes made to the configuration files, you should only use local.settings.json since the appsettings.json was renamed to local.settings.json

Reference to the change: azure-functions-cli

Answer 2

Only environment variables are supported for app settings and connection strings. appsettings.json is not supported.

However, you can use Azure Resource Manager (ARM) Templates to configure the settings for your Function App. Here's a blog post that describe this in more detail.

Answer 3

For dependencies you should use/create the project.json inside your function. There you can specify your dependencies. Please check: https://docs.microsoft.com/en-us/azure/azure-functions/functions-reference-csharp#package-management

For example:

{
  "frameworks": {
    "net46":{
      "dependencies": {
        "Microsoft.ProjectOxford.Face": "1.1.0"
      }
    }
   }
}

Answer 4

Configuration source customization is available beginning in Azure Functions host versions 2.0.14192.0 and 3.0.14191.0.

To specify additional configuration sources, override the ConfigureAppConfiguration method in your function app's StartUp class.

using System.IO;
using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
[assembly: FunctionsStartup(typeof(MyNamespace.Startup))]
using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
[assembly: FunctionsStartup(typeof(MyNamespace.Startup))]
namespace MyNamespace
{
    public class Startup : FunctionsStartup
    {
        public override void ConfigureAppConfiguration(IFunctionsConfigurationBuilder 
builder)
        {
            FunctionsHostBuilderContext context = builder.GetContext();

            builder.ConfigurationBuilder
                .AddJsonFile(Path.Combine(context.ApplicationRootPath, 
"appsettings.json"), optional: true, reloadOnChange: false)
                .AddJsonFile(Path.Combine(context.ApplicationRootPath, $"appsettings. 
{context.EnvironmentName}.json"), optional: true, reloadOnChange: false)
                .AddEnvironmentVariables();
        }
    }
}

// update configuration in csproject

<None Update="appsettings.json">
  <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>      
</None>

<None Update="appsettings">
    <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    <CopyToPublishDirectory>Never</CopyToPublishDirectory>
</None>

From inside the Startup.Configure method, you can extract values from the IConfiguration instance into your custom type using the following code:

builder.Services.AddOptions<MyOptions>()
    .Configure<IConfiguration>((settings, configuration) =>
    {
        configuration.GetSection("MyOptions").Bind(settings);
    });

using System;
using Microsoft.Extensions.Options;

public class HttpTrigger
{
    private readonly MyOptions _settings;

    public HttpTrigger(IOptions<MyOptions> options)
    {
        _settings = options.Value;
    }
}

Refer: https://docs.microsoft.com/en-us/azure/azure-functions/functions-dotnet-dependency-injection#customizing-configuration-sources

Answer 5

In Azure Functions, setting are stored in local.settings.json (create this file if doesn't exist in your solution/ name should be exact as mentioned).

once you add setting file, you have to configure it under your Run() method as mentioned bellow,

When Accessing setting, use below

IConfigurationRoot config;
config["fromEmail"];

use below command to publish settings

func azure functionapp publish *YourAppName* --publish-local-settings -i

Answer 6

For your needs the answer is YES! Azure Functions can use appsettings.json for your configurations. But there are some ordering sequence that Azure will do when a Function is requested.

1º) Azure will look for that KEYS that you used on .GetEnvironmentVariables("[KEY]") method, through Keys that were configured on Application Settings blade in Azure Functions settings

2º) If Azure wasn't able to find out that configurations through Application Settings keys, then Azure will try looking for after appsettings.json file into your root folder of the Function that you working on.

3º) Finally, if Azure wasn't able to find out this keys either on Application Settings neither on appsettings.json file, then Azure will do the last attempt to find out web.config for looking for into this file appsettings section keys.

For your appreciation, you'll able to find out these configurations by the sample on my github repo: here and here

I hope that these information help you.