Shiny-server on NecTAR

To add shiny server to NecTAR VM that is already running rstudio server:

1. give the machine a DNS entry with https, see https://swift.rc.nectar.org.au/v1/AUTH_a404f16e313b4b09ac35d183a2f95afe/tutorials-jekyll-test-build-I722423cbb7cadc02889ae2f885ea3802f1565276-3/dns-with-designate/01-overview.html

2. install shiny-server https://www.rstudio.com/products/shiny/download-server/ubuntu/

3. check that shiny-server is running on the default port 3838
wget -O - http://localhost:3838

4. update the nginx config following https://support.rstudio.com/hc/en-us/articles/213733868-Running-Shiny-Server-with-a-Proxy

## should have this block outside of the server block
map $http_upgrade $connection_upgrade {
      default upgrade;
      ''      close;
}


server {

  ## redirect /app to /app/
  rewrite ^/app$ $scheme://$http_host/app/ permanent;

  # shiny-server
  location /app/ {
      rewrite ^/app/(.*)$ /$1 break;
      proxy_set_header    Host $host;
      proxy_set_header    X-Real-IP $remote_addr;
      proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header    X-Forwarded-Proto $scheme;
      proxy_pass http://localhost:3838;
      proxy_redirect / $scheme://$http_host/app/;
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection $connection_upgrade;
      proxy_read_timeout 20d;
      proxy_buffering off;
    }


  ## should also have a block for rstudio-server along the lines of
    location / {
      proxy_pass http://localhost:8787;
      proxy_redirect http://localhost:8787/ $scheme://$http_host/;
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection $connection_upgrade;
      proxy_read_timeout 20d;
    }

    ## other stuff
}

## check the config:
sudo nginx -t

## reload it:
sudo nginx -s reload

## should see the demo page at https://your-server.cloud.edu.au/app

## apps are served out of /srv/shiny-server

cd /srv/shiny-server
sudo ln -s hello .

## then https://your-server.cloud.edu.au/app/hello/