asp.net - How to read Elastic Beanstalk Environment Properties in .net?

Question

How can I read the Environment Properties from my AWS Elastic Beanstalk Application found here:

Configuration > Software Configuration > Environment Properties

None of the following approaches work:

ConfigurationManager.AppSettings["MyServiceUrl"]
ConfigurationManager.AppSettings["aws:elasticbeanstalk:application:environment.MyServiceUrl"]
Environment.GetEnvironmentVariable("MyServiceUrl")
Environment.GetEnvironmentVariable("aws:elasticbeanstalk:application:environment.MyServiceUrl")

The 'fully qualified' name attempt comes from the AWS EB documentation.

Any ideas?

Answer 1

In your .ebextensions/myoptions.config file:

option_settings:
  - option_name: MyServiceUrl
    value: change me

This will add the "MyServiceUrl" option in your EB Environment Properties section (as you're seeing already). When deployed, this will add the following to your Web.Config file:

<appSettings>
  <add key="MyServiceUrl" value="change me" />
</appSettings>

If you RDP into your EC2 instance, you'll see this.

When you change the property using the EB console, the setting will be modified in your Web.Config file.

So you access this property using the standard AppSettings method:

string value = ConfigurationManager.AppSettings["MyServiceUrl"];

The Catch:

You need to ensure that your Web.Config file does not contain this setting, otherwise EB does not replace it. If your Visual Studio deployment package includes this setting, then EB will not replace it and you will always receive the deployed value when you access the property via your code.

The Solution:

In you Web.Release.config file, have the setting removed during Visual Studio deployment:

<appSettings>
  <add key="MyServiceUrl" xdt:Transform="Remove" xdt:Locator="Match(key)" />
</appSettings>

This will remove the setting from Web.Config during Visual Studio deployment and will allow EB to add the value into the file during EB deployment.