Azure WebApp Containers and AppSettings/Environment Variables - azure

Question

I've created an AzureWebApp running a docker image. The app starts, but it does not appear to be getting a connection string. I've defined the connection string as an AppSetting but I am not seeing that setting passed as an environment variable.
Should I expect to see my AppSetting on the container output? Something like
docker run -e CONNSTR=FOO
The docs imply that it should just be passed automatically, but I feel like I'm missing something.
Thanks
Joe

Answer 1

Turns out it was working all along. I had a legit issue with authenticating against the db. I needed some logging in the service to verify that it was getting the right connection string.
It appears that the app settings are passed to the container implicitly without showing up in the logs as an -e param.

Answer 2

I run into a similar issues when deploying an .NET Core 2 Azure Function, which was reading settings and connection strings using System.Configuration.ConfigurationManager. The root cause in my case was that ASP.NET Core introduced a new configuration API.
Find more details at https://learn.microsoft.com/en-us/aspnet/core/fundamentals/configuration/?view=aspnetcore-2.0&tabs=basicconfiguration.
Assuming you're deploying an ASP.NET Core application deployed into Web Apps for Containers, you may be running into a similar issue. Please try to the following:
a) Initialize the configuration as follows:
using Microsoft.Extensions.Configuration;
...
IConfigurationRoot configuration = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("local.settings.json")
.AddEnvironmentVariables()
.Build();
b) Read connection strings as follows:
configuration.GetConnectionString("StorageAccountConnectionString");
c) Read settings as follows:
configuration["ContainerName"];
Here is a sample configuration file for my Azure Function:
{
"IsEncrypted": true,
"Values": {
"AzureWebJobsStorage": "UseDevelopmentStorage=true",
"AzureWebJobsDashboard": "UseDevelopmentStorage=true",
"ContainerName": "container"
},
"Host": {
"LocalHttpPort": 7071
},
"ConnectionStrings": {
"StorageAccountConnectionString": "UseDevelopmentStorage=true"
}
}