> For the complete documentation index, see [llms.txt](https://weihanglo.gitbook.io/debian-server-for-r-computing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://weihanglo.gitbook.io/debian-server-for-r-computing/other/other_nginx.md).

# Nginx and Shiny Server

![](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Nginx_logo.svg/2000px-Nginx_logo.svg.png)

NGINX is a open-source, high-performance HTTP server with simple configuration and low resource consumption. NGINX powers many top sites, such as Netflix, Airbab, and Github.

In this topic, you will learn how to configure a simple HTTP server and a reverse proxy server for `R-shiny` with NGINX.

## Installation

To download and install **NGINX**. Execute the following commands.

```bash
$ sudo apt-get update && sudo apt-get install nginx
```

To verify your installation, access `http://your-ip-address`. You should see the default nginx page like below (if port forwarding is configured correctly).

![](/files/-M0R5WhOCu-hBN7X13xc)

## Simple Configuration

Simple commands for start/stop/restart `NGINX` server.

```bash
$ sudo service nginx stop
$ sudo service nginx start
$ sudo service nginx restart
```

To make sure that NGINX server will restart automatically after rebooted, execute this:

```bash
sudo update-rc.d nginx defaults
```

## HTTP Server Configuration

NGINX's configuration capabilities are extensive and flexible. Thus, we will focus on simple HTTP server configuration for static content in this section.

To configure your server, open `/etc/nginx/nginx.conf`. This is the global config file of NGINX.

```bash
$ vim /etc/nginx/nginx.conf
```

Next, find the `server` block within `http` block, there may be some example or default setting in the block.

```
http {

  # other config blocks...

  server {
    # some configuration
    # set your config here
  }
}
```

Now, let our server listen on the default TCP port `80`. Do not forget the **trailing semicolon**.

```
server {
  listen 80;
}
```

The default root folder of the web server is `/var/www/html`. To change files in this path, you should always be a sudoer. For convenience sake, we will change the `root` path to the home directory of the web server administrator.

First, create a folder `www-data` in your web admin's home directory and a subfolder named `www-data` in it. After that, create a new folder in the `www-data` that named as the domain name/hostname of you server.

```bash
$ mkdir -p /home/a-web-admin/www-data/
$ cd /home/a-web-admin/www-data
$ mkdir example.domain
```

Next, add a `server_name` and a `root` parameters into NGINX config file.

```
server {
  listen 80;

  server_name example.domain;
  root /home/a-web-admin/www-data/example.domain/;

}
```

Finally, to handle request from clients, add `location` block inside the server block.

Add the following location block to the server block:

```
location / {

}
```

This `location` block specifies the `/` prefix compared with the URI from the request. The URI will be added to the `root` for fetching local data under the `root` concatenate with `/` path.

That is, a `http://example.domain/image.png` request may try to get an image right under you `/home/a-web-admin/www-data/example.domain/image.png` if exists.

If you add another location like below:

```
location /image/ {
  # other configuration...
}
```

The requests such as `http://example.domain/image/something.jpg` would try to get file with the path `home/a-web-admin/www-data/example.domain/image/something.jpg`.

For further basic configuration, see [NGINX Official Tutorial](http://nginx.org/en/docs/beginners_guide.html).

## R Shiny server with NGINX

[R Shiny](http://shiny.rstudio.com/) is a web application framework that can turn analyses into web applications without any web knowledge.

In this section, we will learn how to configure a **Shiny server** with the power of NGINX.

### Install and Configure The Shiny Server

provides a convenient way to install and configure your R-shiny server. However, we would do some trick to combine Shiny and NGINX.

First, install shiny package for R.

```bash
$ sudo su - \
-c "R -e \"install.packages('shiny', repos='https://cran.rstudio.com/')\""
```

Because **RStudio** company only provides Shiny server of **Ubuntu** version, we will use this **Ubuntu** version temporarily.

```bash
$ sudo apt-get install gdebi-core
$ wget https://download3.rstudio.org/ubuntu-12.04/x86_64/shiny-server-1.4.2.786-amd64.deb
$ sudo gdebi shiny-server-1.4.2.786-amd64.deb
```

The default port for R-Shiny server is **3838**. That means any can connect to the server through the URL **http\://\<server-ip/hostname>:3838**.

Simple commands for start/stop/restart your `shiny-server`.

```bash
$ sudo systemctl start shiny-server
$ sudo systemctl stop shiny-server
$ sudo systemctl restart shiny-server
```

The default configure file for shiny-server locates at `/etc/shiny-server/shiny-server.conf` file. This config file use nearly same syntax and parameters as **NGINX** config file. For example, if you want to change the default port to **13838**, modify it as below;

```
server {
  listen 13838;
  # other configuration...
}
```

Shiny Server administration document explains lots of features clearly. We will only show some useful config in this tutorial.

First, create a new account to manage all Shiny apps.

```bash
$ sudo adduser shinyapps

# Then, login as shinyapps. Create a root folder to manage apps.

$ mkdir -p ~/ShinyApps/
```

Here is the example configuration file at `/etc/shiny-server/shiny-server.conf`.

```
server {
  listen 3838;

  # For root shiny server (in shinyapps user home folder)
  location / {

    # The shiny-server process would run by user `shinyapps`
    run_as shinyapps;

    # Save logs here
    log_dir /var/log/shiny-server;

    # Path to shiny server for separate apps
    site_dir /home/shinyapps/ShinyApps;

    # List contents of a (non-Shiny-App) directory when clients visit corresponding URIs
    directory_index on;
  }

  # Allow users to host their own apps in `~/ShinyApps`
  location /users {
    run_as :HOME_USER:;
    user_dirs;
  }
}
```

To test your configs, put your Shiny apps in `~/ShinyApps/`. Assumed the hierarchy of your shiny app looks like this,

```bash
myapps/
├── server.R
└── ui.R
```

You should move your app folder into `~/ShinyApps/` directory such as `~/ShinyApps/myapps/`.

Finally, use a web browser to open `http://localhost:3838/myapps/`. If you can connect to your app, the shiny server is successfully installed and working.

### Add Configurations to NGINX for Shiny Server

If you want to combine Shiny Server with NGINX HTTP Server. Here is the example configuration of NGINX.

```
server {
  # Other locations and configurations...

  location /shiny/ { # shiny server will locate at `http://example.domain/shiny/`
    rewrite ^/shiny/(.*)$ /$1 break;
    proxy_pass http://localhost:3838;
    proxy_redirect http://localhost:3838/ $scheme://$host/shiny/;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_read_timeout 20d;
  }
}
```

If your shiny server serves at port 3838, NGINX will pass the request to your shiny server. Then redirect the URL as something like `http://example.domain/shiny/you-apps/`.

### Other tips

* For more NGINX configuration, see [this resource](https://www.nginx.com/resources/wiki/).
* For more Shiny server configs, see [this guide](http://docs.rstudio.com/shiny-server/).