So we've been rebuilding the Sitecore MVP site currently, and you can see how were going as the repository is Open Source, meaning you can see how we're progressing right here.One of the issues we ran into during this build stopped our site from loading in the Sitecore Experience Editor, we kept getting the following 404 error:

Error Rendering Sitecore.JavaScriptServices.ViewEngine.Presentation.JsLayoutRenderer: The remote server returned an error: (404) Not Found. at System.Net.WebClient.UploadDataInternal(Uri address, String method, Byte[] data, WebRequest& request) at System.Net.WebClient.UploadString(Uri address, String method, String data) at Sitecore.JavaScriptServices.ViewEngine.Http.RenderEngine.Invoke[T](String moduleName, String functionName, Object[] functionArgs) at Sitecore.JavaScriptServices.ViewEngine.Presentation.JssRenderer.PerformRender(TextWriter writer, IRenderEngine renderEngine, String moduleName, String functionName, Object[] functionArgs) at Sitecore.JavaScriptServices.ViewEngine.Presentation.JssRenderer.Render(TextWriter writer) at Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Render(Renderer renderer, TextWriter writer, RenderRenderingArgs args)

After a bit of digging, it turns out we were missing a couple of environment variables in our Docker-Compose yaml. We only had the following values defined for our Rendering Host container:

environment: ASPNETCORE_ENVIRONMENT: "Development" ASPNETCORE_URLS: "http://*:80" Sitecore __InstanceUri: "http://cd"

The two we were missing were the Sitecore__ RenderingHostUri and Sitecore __EnableExperienceEditor values. Once we added those back in, our Experience Editor integration started working fine again. The final rendering container definition we ended up with was:

environment: ASPNETCORE_ENVIRONMENT: "Development" ASPNETCORE_URLS: "http://*:80" Sitecore__ InstanceUri: "http://cd" Sitecore __RenderingHostUri: "https://${RENDERING_HOST}" Sitecore__ EnableExperienceEditor: "true"

You can see our full Docker-Compose yaml file here.