EF Core 2.0 connection string in Azure Functions .NET Core

Question

I'm using EF core 2.0 in Azure Functions using .net core. I'm trying to read db ConnectionString from local.settings.json, which is defined:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "AzureWebJobsDashboard": "UseDevelopmentStorage=true"
  },
  "ConnectionStrings": {
    "MyDbConnStr": "Data Source=.;Initial Catalog=xxxxxxx"
  }
}

Environment.GetEnvironmentVariable() doesn't return any connection string info neither I can use ConfigurationManager.ConnectionStrings with .net core. How do I access the connection string from the code?

Answer 1

You could use one of the helper classes in Microsoft.Azure.WebJobs.Host:

AmbientConnectionStringProvider.Instance.GetConnectionString("MyDbConnStr")

This class is delegating the work to internal class called ConfigurationUtility, which does something in line with

var configuration = new ConfigurationBuilder()
    .AddEnvironmentVariables()
    .AddJsonFile("appsettings.json", true)
    .Build();
var conn = configuration.GetConnectionString("MyDbConnStr");

Answer 2

You can use Environment.GetEnvironmentVariable. The keys are "ConnectionStrings:YourKey"

Assuming your local.settings.json looks like the following:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "AzureWebJobsDashboard": "UseDevelopmentStorage=true"
  },
  "ConnectionStrings": {
    "sqldb_connection": "connection_string_here"
  }
}

Use Environment.GetEnvironmentVariable("ConnectionStrings:sqldb_connection", EnvironmentVariableTarget.Process); to get the value