ASP.NET Core 1.0 custom compression middleware and static files issue - asp.net-core

Question

My startup's middleware configuration looks something like this:
public void Configure(IApplicationBuilder app)
{
app.UseCompression();
app.UseIISPlatformHandler();
app.UseApplicationInsightsRequestTelemetry();
app.UseCors("CorsPolicy");
app.UseStaticFiles();
app.UseMvc();
app.UseApplicationInsightsExceptionTelemetry();
}
Since adding the app.UseCompression() middleware, static html files in wwwroot aren't loading correctly anymore. They don't resolve and tend to load indefinitely.
The compression middleware looks as follows and was sourced from here:
public class CompressionMiddleware
{
private readonly RequestDelegate nextDelegate;
public CompressionMiddleware(RequestDelegate next)
{
nextDelegate = next;
}
public async Task Invoke(HttpContext httpContext)
{
var acceptEncoding = httpContext.Request.Headers["Accept-Encoding"];
//Checking that we have been given the correct header before moving forward
if (!(String.IsNullOrEmpty(acceptEncoding)))
{
//Checking that it is gzip
if (acceptEncoding.ToString().IndexOf("gzip", StringComparison.CurrentCultureIgnoreCase) >= 0)
{
using (var memoryStream = new MemoryStream())
{
var stream = httpContext.Response.Body;
httpContext.Response.Body = memoryStream;
await nextDelegate(httpContext);
using (var compressedStream = new GZipStream(stream, CompressionLevel.Optimal))
{
httpContext.Response.Headers.Add("Content-Encoding", new string[] { "gzip" });
memoryStream.Seek(0, SeekOrigin.Begin);
await memoryStream.CopyToAsync(compressedStream);
}
}
}
else
{
await nextDelegate(httpContext);
}
}
//If we have are given to Accept Encoding header or it is blank
else
{
await nextDelegate(httpContext);
}
}
}
Does anyone know why this could be happening?
Note: I am using DNX 1.0.0-rc1-update1 and the 1.0.0-rc1-final libraries.

Answer 1

I just enabled compression in web.config in /wwwroot folder (like we used to do in IIs applicationHost.config), and it works. There's no need to add a compression middleware.
http://www.brandonmartinez.com/2015/08/20/enable-gzip-compression-for-azure-web-apps/

Answer 2

Compression defined in web.config only works with IIS NOT the self hosted web server.
I tested the CompressionMiddleware example and the problem You are seeing is caused by the Content-Length header.
If the Content-Length is already set, the browser gets confused as the actual size of the response doesn't match the value defined in the header as the content is zipped.
Removing the content-length header solved the problem:
httpContext.Response.Headers.Remove("Content-Length");
httpContext.Response.Headers.Add("Content-Encoding", new string[] { "gzip" });
...even better you could try to specify the actual content-length when the content is zipped.