Exporting

public class Module : IImportsAssembly<Module>
{
    /// <summary>Singleton</summary>
    public static Module Instance { get; } = new();

    /// <summary>Export pre-build action</summary>
    public Action<IHostBuilder> HostBuilderAction = (IHostBuilder cb) => WriteLine("Host builder action");
    /// <summary>Export pre-build action</summary>
    public Action<HostBuilderContext, object> ContainerAction = (HostBuilderContext ctx, object container) => WriteLine("Configuring container");
    /// <summary>Export post-build action</summary>
    public Action<IHost, object> PostBuildAction = (IHost host, object container) => WriteLine("Post-build action");
}

Importing to IHostBuilder

HostingContainer.ModuleImportCached[Module.Instance].ConfigureHostBuilder(hostBuilder, installDependencies) installs module on IHostBuilder.

// Initialize host builder
IHostBuilder hostBuilder = new HostBuilder();
hostBuilder.UseServiceProviderFactory(HostServiceProviderFactory.Instance);
HostingContainer.ModuleImportCached[Module.Instance].ConfigureHostBuilder(hostBuilder, installDependencies: true);
// Capture container
object[] containers = new object[1];
hostBuilder.ConfigureContainer<object>((HostBuilderContext ctx, object container) => containers[0] = container);
// Build host
IHost host = hostBuilder.Build();
// Post-build actions must be invoked manually
if (containers[0] is IHostBuildActions hostBuildActions) foreach (var action in hostBuildActions.PostBuildActions) action(host, hostBuildActions);
// Invoke post build actions
IServiceProvider services = host.Services;

Full Example

Full example

using Avalanche.Hosting;
using Avalanche.Module;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using static System.Console;

public class hostbuilder
{
    public static void Run()
    {
        {
            // <01>
            // Initialize host builder
            IHostBuilder hostBuilder = new HostBuilder();
            hostBuilder.UseServiceProviderFactory(HostServiceProviderFactory.Instance);
            HostingContainer.ModuleImportCached[Module.Instance].ConfigureHostBuilder(hostBuilder, installDependencies: true);
            // Capture container
            object[] containers = new object[1];
            hostBuilder.ConfigureContainer<object>((HostBuilderContext ctx, object container) => containers[0] = container);
            // Build host
            IHost host = hostBuilder.Build();
            // Post-build actions must be invoked manually
            if (containers[0] is IHostBuildActions hostBuildActions) foreach (var action in hostBuildActions.PostBuildActions) action(host, hostBuildActions);
            // Invoke post build actions
            IServiceProvider services = host.Services;
            // </01>
        }
    }

    // <99>
    public class Module : IImportsAssembly<Module>
    {
        /// <summary>Singleton</summary>
        public static Module Instance { get; } = new();

        /// <summary>Export pre-build action</summary>
        public Action<IHostBuilder> HostBuilderAction = (IHostBuilder cb) => WriteLine("Host builder action");
        /// <summary>Export pre-build action</summary>
        public Action<HostBuilderContext, object> ContainerAction = (HostBuilderContext ctx, object container) => WriteLine("Configuring container");
        /// <summary>Export post-build action</summary>
        public Action<IHost, object> PostBuildAction = (IHost host, object container) => WriteLine("Post-build action");
    }
    // </99>

}