.Net 6 Azure Function App with use of Startup class - asp.net-core

Question

I have created an HTTP trigger-based .Net 6 Azure FunctionApp and trying to configure the database connection strings, other key values, and dependency injections for my service classes but, I don't know how to call my configure method of Startup.cs file from Program.cs main function. I am new to FunctionApp-based hosting.
I have tried with IHostBuilder like the following in the Program.cs file, but it says: "does not contain a definition for ConfigureWebHostDefaults" even used the namespace => using Microsoft.AspNetCore.Hosting;
public static void Main(string[] args)
{
var host = new HostBuilder().ConfigureFunctionsWorkerDefaults()
.Build();
host.Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
My Startup.cs file,
[assembly: FunctionsStartup(typeof(Startup))]
namespace kpi
{
public class Startup : FunctionsStartup
{
private static IConfiguration _configuration = null;
public override void Configure(IFunctionsHostBuilder builder)
{
var serviceProvider = builder.Services.BuildServiceProvider();
_configuration = serviceProvider.GetRequiredService<IConfiguration>();
var appSettingsSection = _configuration.GetSection("AppSetting");
builder.Services.Configure<AppSetting>(appSettingsSection);
var appSettings = appSettingsSection.Get<AppSetting>();
RuntimeConfig.appsettings = appSettings;
var ConnectionString = RuntimeConfig.appsettings.AppDBConnection;
builder.Services.AddDbContext<ShardingDbContext>(options =>
options.UseSqlServer(ConnectionString), ServiceLifetime.Transient);
}
}
}
I have used the FunctionStartup assembly, I don't know where I did go wrong, Can anyone help me to configure my connection strings from Startup.cs file in .Net6 Function App project?

Answer 1

You can refer below code to fix your issue. For more details, please read official doc.
Guide for running C# Azure Functions in an isolated process
1. Startup.cs file
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
[assembly: FunctionsStartup(typeof(triggerFunc.Startup))]
namespace triggerFunc
{
public class Startup : FunctionsStartup
{
private static IConfiguration _configuration = null;
public override void ConfigureAppConfiguration(IFunctionsConfigurationBuilder builder)
{
var context = builder.GetContext();
// optional: customize your configuration sources
// here, we add appsettings.json files
// Note that these files are not automatically copied on build or publish.
//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);
}
public override void Configure(IFunctionsHostBuilder builder)
{
// get the configuration from the builder
//var configuration = builder.GetContext().Configuration;
var serviceProvider = builder.Services.BuildServiceProvider();
_configuration = serviceProvider.GetRequiredService<IConfiguration>();
var appSettingsSection = _configuration.GetSection("AppSetting");
builder.Services.Configure<AppSetting>(appSettingsSection);
var appSettings = appSettingsSection.Get<AppSetting>();
RuntimeConfig.appsettings = appSettings;
var ConnectionString = RuntimeConfig.appsettings.AppDBConnection;
builder.Services.AddDbContext<ShardingDbContext>(options =>
options.UseSqlServer(ConnectionString), ServiceLifetime.Transient);
}
}
}
2. Program.cs file
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace triggerFunc
{
public class Program
{
public static async Task Main(string[] args)
{
var builder = Host
.CreateDefaultBuilder(args)
.ConfigureFunctionsWorkerDefaults()
.ConfigureAppConfiguration((hostingContext, configBuilder) =>
{
var env = hostingContext.HostingEnvironment;
;
})
.ConfigureServices((appBuilder, services) =>
{
var configuration = appBuilder.Configuration;
});
await builder.Build().RunAsync();
}
}
}

Answer 2

I just did override the function ConfigureAppConfiguration as below
public override void ConfigureAppConfiguration(IFunctionsConfigurationBuilder builder)
{
FunctionsHostBuilderContext context = builder.GetContext();
builder.ConfigurationBuilder
.AddJsonFile(Path.Combine(context.ApplicationRootPath, "local.settings.json"), optional: true, reloadOnChange: false)
.AddJsonFile(Path.Combine(context.ApplicationRootPath, $"local.settings.{context.EnvironmentName}.json"), optional: true, reloadOnChange: false)
.AddEnvironmentVariables();
}
It's working fine in my local without an isolated way or Program.cs file and I don't know whether this same code will work on a server or not.
My local.setings.json
{
"IsEncrypted": false,
"AppSettings": {
"AppDBConnection": "xyz....."
}
My Startup.cs file below and I can access the AppSettings section from my json file
public class Startup : FunctionsStartup
{
private static IConfiguration _configuration = null;
public override void Configure(IFunctionsHostBuilder builder)
{
//var connectionString = Environment.GetEnvironmentVariable("ConnectionStrings:DBConnection");
var serviceProvider = builder.Services.BuildServiceProvider();
_configuration = serviceProvider.GetRequiredService<IConfiguration>();
var appSettingsSection = _configuration.GetSection("AppSettings");
builder.Services.Configure<AppSettings>(appSettingsSection);
var appSettings = appSettingsSection.Get<AppSettings>();
RuntimeConfig.appsettings = appSettings;
var ConnectionString = RuntimeConfig.appsettings.AppDBConnection;
builder.Services.AddDbContext<ShardingDbContext>(options => options.UseSqlServer(ConnectionString), ServiceLifetime.Transient);
builder.Services.AddScoped<ITestService, TestService>();
}
public override void ConfigureAppConfiguration(IFunctionsConfigurationBuilder builder)
{
FunctionsHostBuilderContext context = builder.GetContext();
builder.ConfigurationBuilder
.AddJsonFile(Path.Combine(context.ApplicationRootPath, "local.settings.json"), optional: true, reloadOnChange: false)
.AddJsonFile(Path.Combine(context.ApplicationRootPath, $"local.settings.{context.EnvironmentName}.json"), optional: true, reloadOnChange: false)
.AddEnvironmentVariables();
}
}