AWS Elastic Beanstalk environment variables in ASP.NET Core 1.0
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.
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 Files\Amazon\ElasticBeanstalk\config\containerconfiguration",
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.
Had the same problem, and just received a reply from AWS support about this issue. Apparently environment variables are not properly injected into ASP.NET Core applications in elastic beanstalk.
As far as I know, they're working to fix the problem.
The workaround is to parse C:\Program Files\Amazon\ElasticBeanstalk\config\containerconfiguration into the configuration builder. This file is part of your elastic beanstalk environment and should be accessible upon deploying your project.
First add the file:
var builder = new ConfigurationBuilder()
.SetBasePath("C:\\Program Files\\Amazon\\ElasticBeanstalk\\config")
.AddJsonFile("containerconfiguration", optional: true, reloadOnChange: true);
Then access the values:
var env = Configuration.GetSection("iis:env").GetChildren();
foreach (var envKeyValue in env)
{
var splitKeyValue = envKeyValue.Value.Split('=');
var envKey = splitKeyValue[0];
var envValue = splitKeyValue[1];
if (envKey == "HelloWorld")
{
// use envValue here
}
}
Courtesy of G.P. from Amazon Web Services
I implemented the other answer to create a convenient workaround to load the environment properties from Elastic Beanstalk directly into your ASP.NET Core app configuration.
For ASP.NET Core 2.0 - edit your Program.cs
Note that this WebHost build was taken from the source code of WebHostBuilder.CreateDefaultBuilder()
https://github.com/aspnet/MetaPackages/blob/dev/src/Microsoft.AspNetCore/WebHost.cs
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Server.Kestrel.Core;
using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
namespace NightSpotAdm
{
public class Program
{
public static void Main(string[] args)
{
BuildWebHost(args).Run();
}
public static IWebHost BuildWebHost(string[] args)
{
// TEMP CONFIG BUILDER TO GET THE VALUES IN THE ELASTIC BEANSTALK CONFIG
IConfigurationBuilder tempConfigBuilder = new ConfigurationBuilder();
tempConfigBuilder.AddJsonFile(
@"C:\Program Files\Amazon\ElasticBeanstalk\config\containerconfiguration",
optional: true,
reloadOnChange: true
);
IConfigurationRoot tempConfig = tempConfigBuilder.Build();
Dictionary<string, string> ebConfig = ElasticBeanstalk.GetConfig(tempConfig);
// START WEB HOST BUILDER
IWebHostBuilder builder = new WebHostBuilder()
.UseKestrel()
.UseContentRoot(Directory.GetCurrentDirectory());
// CHECK IF EBCONFIG HAS ENVIRONMENT KEY IN IT
// IF SO THEN CHANGE THE BUILDERS ENVIRONMENT
const string envKey = "ASPNETCORE_ENVIRONMENT";
if (ebConfig.ContainsKey(envKey))
{
string ebEnvironment = ebConfig[envKey];
builder.UseEnvironment(ebEnvironment);
}
// CONTINUE WITH WEB HOST BUILDER AS NORMAL
builder.ConfigureAppConfiguration((hostingContext, config) =>
{
IHostingEnvironment env = hostingContext.HostingEnvironment;
// ADD THE ELASTIC BEANSTALK CONFIG DICTIONARY
config.AddJsonFile(
"appsettings.json",
optional: true,
reloadOnChange: true
)
.AddJsonFile(
$"appsettings.{env.EnvironmentName}.json",
optional: true,
reloadOnChange: true
)
.AddInMemoryCollection(ebConfig);
if (env.IsDevelopment())
{
Assembly appAssembly = Assembly.Load(new AssemblyName(env.ApplicationName));
if (appAssembly != null)
{
config.AddUserSecrets(appAssembly, optional: true);
}
}
config.AddEnvironmentVariables();
if (args != null)
{
config.AddCommandLine(args);
}
})
.ConfigureLogging((hostingContext, logging) =>
{
logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging"));
logging.AddConsole();
logging.AddDebug();
})
.UseIISIntegration()
.UseDefaultServiceProvider(
(context, options) => { options.ValidateScopes = context.HostingEnvironment.IsDevelopment(); })
.ConfigureServices(
services =>
{
services.AddTransient<IConfigureOptions<KestrelServerOptions>, KestrelServerOptionsSetup>();
});
return builder.UseStartup<Startup>().Build();
}
}
public static class ElasticBeanstalk
{
public static Dictionary<string, string> GetConfig(IConfiguration configuration)
{
return
configuration.GetSection("iis:env")
.GetChildren()
.Select(pair => pair.Value.Split(new[] { '=' }, 2))
.ToDictionary(keypair => keypair[0], keypair => keypair[1]);
}
}
}
For ASP.NET Core 1.0
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddJsonFile(@"C:\Program Files\Amazon\ElasticBeanstalk\config\containerconfiguration", optional: true, reloadOnChange: true)
.AddEnvironmentVariables();
var config = builder.Build();
builder.AddInMemoryCollection(GetEbConfig(config));
Configuration = builder.Build();
}
private static Dictionary<string, string> GetEbConfig(IConfiguration configuration)
{
Dictionary<string, string> dict = new Dictionary<string, string>();
foreach (IConfigurationSection pair in configuration.GetSection("iis:env").GetChildren())
{
string[] keypair = pair.Value.Split(new [] {'='}, 2);
dict.Add(keypair[0], keypair[1]);
}
return dict;
}
Instead of having to parse the containerconfiguration you can leverage the ebextensions options to set the variable as part of your deploy process:
commands:
set_environment:
command: setx ASPNETCORE_ENVIRONMENT "Development" /M
This will set a global environment variable as part of your application deployment. This variable use-case is officially supported and documented by Microsoft.
After deploying your app you can verify the setting is set correctly in the EC2 instance:
