/// <summary>
/// Add json file settings based on current environment and the specified
/// environment inheritance layers.
/// If environments param is null, only appsettings.json will be added.
/// </summary>
/// <param name="configBuilder">config builder</param>
/// <param name="environments">array of defined environments</param>
/// <returns>config builder</returns>
private static IConfigurationBuilder AddJsonFiles(
this IConfigurationBuilder configBuilder,
IEnumerable <HostEnvironment> environments)
{
var currentEnvName = HostEnvironment.Environment;
// Try to look the current environment up from the given environment list
var env = environments?.FirstOrDefault(e => string.Equals(e.Name, currentEnvName, StringComparison.OrdinalIgnoreCase));
if (env == null)
{
// If the current environment cannot be found from the environments list, we fall back to
// the .net core behavior by creating a temp environment using current environment's name.
env = new HostEnvironment(currentEnvName);
}
// Find the layering hierarchy (sigle direction list from children to parent), then reverse it (parent to children).
var layers = new List <HostEnvironment>();
while (env != null)
{
layers.Add(env);
env = env.Parent;
}
layers.Reverse();
// Add json files based on parent to child chains. Note appsettings.json is always included first.
configBuilder.AddJsonFile("appsettings.json", optional: true, reloadOnChange: false);
foreach (var environment in layers)
{
configBuilder.AddJsonFile($"appsettings.{environment.Name}.json", optional: true, reloadOnChange: false);
}
return(configBuilder);
}
/// <summary>
/// Initializes a new Environment object
/// </summary>
/// <param name="name">environment name which is set in IHostEnvironment</param>
/// <param name="parent">Parent environment, can be null and defaults to null</param>
public HostEnvironment(string name, HostEnvironment parent = null)
{
this.Name = name ?? throw new ArgumentNullException(nameof(name));
this.Parent = parent;
}
