I’m using .NET 6.0, my appsettings.json looks like this:
{
"Logging": {
"LogLevel": {
"Default": "Debug",
"System": "Information",
"Microsoft": "Information"
}
},
"Client_Version": {
"Name_of_client": "Mordor",
"Environment_of_client": "PROD"
}
}
Based on Name_of_client and Environment_of_client at runtime, different appsettings.json is used. In this case appsettings.Mordor.PROD.json is being used.
When I publish a profile like this mordor-prod.pubxml, I want that this appropriate appsettings.json is published.
And when using publish profile like this mordor-stage.pubxml to publish appsettings.json with this:
"Client_Version": {
"Name_of_client": "Mordor",
"Environment_of_client": "STAGE"
}
In .NET Core 2.1, I’m using a web.config with a xdt:Transform, and works fine.
Not easy to do with just .NET, IMO, I think you’ll need additional tools.
But even if you can’t change the appsettings.XXX.json file, you can change the configuration in code. As you know, the appsettings.XXX.json file (and other sources, such as environment variables, user secrets, and possibly others) are put together inside the IConfiguration instance automatically (in ASP.NET Core, for console, you need to do it yourself). From there, you are free to modify the values. See also Using ASP.NET Core’s ConfigurationBuilder in a Test Project.