AWS Elastic Beanstalk environment variables in ASP.NET Core 1.0

Question

How do I get environment variables from elastic beanstalk into an asp.net core mvc application? I have added a .ebextensions folder with app.config file in it with the following:

option_settings:
- option_name: HelloWorld
  value: placeholder

- option_name: ASPNETCORE_ENVIRONMENT
  value: placeholder

The .ebextensions folder is included in the publish package.

On deployment, both the variables are visible in the aws elasticbeanstalk console at Configuration > Software Configuration > Environment Variables

However, when I try to read the variables in the application, none of the below options are working:

Environment.GetEnvironmentVariable("HelloWorld") // In controller
Configuration["HelloWorld"] // In startup.cs

Any ideas on what I could be missing? Thanks.

question from:https://stackoverflow.com/questions/40127703/aws-elastic-beanstalk-environment-variables-in-asp-net-core-1-0

Answer 1

I just implemented a slightly other solution which injects the beanstalk environment variables to the program so that you may access them by Environment.GetEnvironmentVariable():

private static void SetEbConfig()
{
    var tempConfigBuilder = new ConfigurationBuilder();

    tempConfigBuilder.AddJsonFile(
        @"C:Program FilesAmazonElasticBeanstalkconfigcontainerconfiguration",
        optional: true,
        reloadOnChange: true
    );

    var configuration = tempConfigBuilder.Build();

    var ebEnv =
        configuration.GetSection("iis:env")
            .GetChildren()
            .Select(pair => pair.Value.Split(new[] { '=' }, 2))
            .ToDictionary(keypair => keypair[0], keypair => keypair[1]);

    foreach (var keyVal in ebEnv)
    {
        Environment.SetEnvironmentVariable(keyVal.Key, keyVal.Value);
    }
}

Simply call SetEbConfig(); before building your webhost. With this solution, also AWS SDK does read it's settings like AWS_ACCESS_KEY_ID correctly.