Hosting Extensions

Many cloud hosting providers, including Cloud Foundry, dynamically provide port numbers at runtime. For ASP.NET Core applications, Steeltoe provides a extension methods for both IWebHostBuilder and IHostBuilder to read in these values and configure the application to lisen on the assigned port.

UseCloudHosting

UseCloudHosting is provided in the NuGet package Steeltoe.Common.Hosting. This extension will automatically use the environment variables PORT or SERVER_PORT (when present) to set the address the application is listening on for HTTP traffic. When a port is not found in the environment or passed in as a parameter, the application will be configured to listen on port 8080. This sample illustrates basic usage:

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            ...
            .UseCloudHosting() // Listen for HTTP on port defined in 'PORT', 'SERVER_PORT' or else 8080
            ...

The extension includes an optional parameter to explicitly set ports used for HTTP and HTTPS, which is particularly useful when you are running multiple services at once on your workstation that will later be deployed to a cloud platform.

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            ...
            .UseCloudHosting(5001, 5002) // Listen for HTTP on port defined in 'PORT', 'SERVER_PORT' or else listen for HTTP on 5001 and HTTPS on 5002
            ...

NOTE: If either environment variable PORT or SERVER_PORT is found, neither of the optional parameters will be used.

UseCloudFoundryHosting

UseCloudFoundryHosting is now deprecated, but is still available in the NuGet package Steeltoe.Extensions.Configuration.CloudFoundryCore. This extension has been superseded by UseCloudHosting, but is still available in the 2.x line. This extension will automatically use the environment variable PORT (when present) to set the address the application is listening on. This sample illustrates basic usage:

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            ...
            .UseCloudFoundryHosting()
            ...

The extension includes an optional parameter to explicitly set the HTTP port, which is particularly useful when you are running multiple services at once on your workstation that will later be deployed to a cloud platform.

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            ...
            .UseCloudFoundryHosting(5001)
            ...

NOTE: As this extension is intended for use on Cloud Foundry, if the 'PORT' environment variable is present, it will always override the parameter.