Add support for environment variables for configuration

[markjritchie]

As far as I can see there is no way to use environment variables to override the appsettings.json for the downstream API.

The file src/Microsoft.Identity.Web.TokenAcquisition/TokenAcquirerFactory.cs has the following method:

private IConfiguration ReadConfiguration()
        {
            if (Configuration == null)
            {
                // Read the configuration from a file
                var builder = new ConfigurationBuilder();
                string basePath = DefineConfiguration(builder);
                builder.SetBasePath(basePath)
                       .AddJsonFile("appsettings.json", optional: true);
                Configuration = builder.Build();
            }
            return Configuration;
        }

Changing it to:

private IConfiguration ReadConfiguration()
        {
            if (Configuration == null)
            {
                // Read the configuration from a file
                var builder = new ConfigurationBuilder();
                string basePath = DefineConfiguration(builder);
                builder.SetBasePath(basePath)
                       .AddJsonFile("appsettings.json", optional: true)
                       .AddEnvironmentVariables();
                Configuration = builder.Build();
            }
            return Configuration;
        }

would provide better flexibility.

Alternatively a way to pass in the configuration to be used would also work.

[jmprieur]

Thanks @markjritchie
Would you like to propose a PR?

[markjritchie]

Happy to, but thought I should check that I wasn't missing something

[markjritchie]

Is there a guide on setting up the necessary PAT to push to a branch and create the PR?

I get authentication failed when I try to push the branch

[jmprieur]

No. there is no PAT. You would have to fork the repo.