**Note:** For Ubuntu 14.04, *supervisord* is recommended as a solution for monitoring the Kestrel process. *systemd* isn't available on Ubuntu 14.04. [See previous version of this document](https://github.com/aspnet/Docs/blob/e9c1419175c4dd7e152df3746ba1df5935aaafd5/aspnetcore/publishing/linuxproduction.md)
Copy the ASP.NET Core app to the server using whatever tool integrates into the organization's workflow (for example, SCP, FTP). Test the app, for example:
* From the command line, run `dotnet <app_assembly>.dll`.
* In a browser, navigate to `http://<serveraddress>:<port>` to verify the app works on Linux.
Kestrel is great for serving dynamic content from ASP.NET Core. However, the web serving capabilities aren't as feature rich as servers such as IIS, Apache, or Nginx. A reverse proxy server can offload work such as serving static content, caching requests, compressing requests, and SSL termination from the HTTP server. A reverse proxy server may reside on a dedicated machine or may be deployed alongside an HTTP server.
For the purposes of this guide, a single instance of Nginx is used. It runs on the same server, alongside the HTTP server. Based on requirements, a different setup may be choosen.
Because requests are forwarded by reverse proxy, use the Forwarded Headers Middleware from the [Microsoft.AspNetCore.HttpOverrides](https://www.nuget.org/packages/Microsoft.AspNetCore.HttpOverrides/) package. The middleware updates the `Request.Scheme`, using the `X-Forwarded-Proto` header, so that redirect URIs and other security policies work correctly.
When using any type of authentication middleware, the Forwarded Headers Middleware must run first. This ordering ensures that the authentication middleware can consume the header values and generate correct redirect URIs.
Invoke the [UseForwardedHeaders](/dotnet/api/microsoft.aspnetcore.builder.forwardedheadersextensions.useforwardedheaders) method in `Startup.Configure` before calling [UseAuthentication](/dotnet/api/microsoft.aspnetcore.builder.authappbuilderextensions.useauthentication) or similar authentication scheme middleware:
Invoke the [UseForwardedHeaders](/dotnet/api/microsoft.aspnetcore.builder.forwardedheadersextensions.useforwardedheaders) method in `Startup.Configure` before calling [UseIdentity](/dotnet/api/microsoft.aspnetcore.builder.builderextensions.useidentity) and [UseFacebookAuthentication](/dotnet/api/microsoft.aspnetcore.builder.facebookappbuilderextensions.usefacebookauthentication) or similar authentication scheme middleware:
If no [ForwardedHeadersOptions](/dotnet/api/microsoft.aspnetcore.builder.forwardedheadersoptions) are specified to the middleware, the default headers to forward are `None`.
Use `apt-get` to install Nginx. The installer creates a System V init script that runs Nginx as daemon on system startup. Since Nginx was installed for the first time, explicitly start it by running:
To configure Nginx as a reverse proxy to forward requests to our ASP.NET Core app, modify `/etc/nginx/sites-available/default`. Open it in a text editor, and replace the contents with the following:
Once the Nginx configuration is established, run `sudo nginx -t` to verify the syntax of the configuration files. If the configuration file test is successful, force Nginx to pick up the changes by running `sudo nginx -s reload`.
The server is setup to forward requests made to `http://<serveraddress>:80` on to the ASP.NET Core app running on Kestrel at `http://127.0.0.1:5000`. However, Nginx isn't set up to manage the Kestrel process. *systemd* can be used to create a service file to start and monitor the underlying web app. *systemd* is an init system that provides many powerful features for starting, stopping, and managing processes.
**Note:** Linux has a case-sensitive file system. Setting ASPNETCORE_ENVIRONMENT to "Production" results in searching for the configuration file *appsettings.Production.json*, not *appsettings.production.json*.
With the reverse proxy configured and Kestrel managed through systemd, the web app is fully configured and can be accessed from a browser on the local machine at `http://localhost`. It's also accessible from a remote machine, barring any firewall that might be blocking. Inspecting the response headers, the `Server` header shows the ASP.NET Core app being served by Kestrel.
Since the web app using Kestrel is managed using `systemd`, all events and processes are logged to a centralized journal. However, this journal includes all entries for all services and processes managed by `systemd`. To view the `kestrel-hellomvc.service`-specific items, use the following command:
Linux Security Modules (LSM) is a framework that's part of the Linux kernel since Linux 2.6. LSM supports different implementations of security modules. [AppArmor](https://wiki.ubuntu.com/AppArmor) is a LSM that implements a Mandatory Access Control system which allows confining the program to a limited set of resources. Ensure AppArmor is enabled and properly configured.
Close off all external ports that are not in use. Uncomplicated firewall (ufw) provides a front end for `iptables` by providing a command line interface for configuring the firewall. Verify that `ufw` is configured to allow traffic on any ports needed.
The PCRE library is required for regular expressions. Regular expressions are used in the location directive for the ngx_http_rewrite_module. The http_ssl_module adds HTTPS protocol support.
* Harden the security by employing some of the practices depicted in the following */etc/nginx/nginx.conf* file. Examples include choosing a stronger cipher and redirecting all traffic over HTTP to HTTPS.
Clickjacking is a malicious technique to collect an infected user's clicks. Clickjacking tricks the victim (visitor) into clicking on an infected site. Use X-FRAME-OPTIONS to secure the site.
This header prevents most browsers from MIME-sniffing a response away from the declared content type, as the header instructs the browser not to override the response content type. With the `nosniff` option, if the server says the content is "text/html", the browser renders it as "text/html".
