44 Installing and configuring Shiny for PEcAn

authors - Alexey Shiklomanov - Rob Kooper

NOTE: Instructions are only tested for CentOS 6.5 and Ubuntu 16.04 NOTE: Pretty much every step here requires root access.

44.1 Install the Shiny R package and Shiny server

Follow the instructions on the Shiny download page for the operating system you are using.

44.2 Modify the shiny configuration file

The Shiny configuration file is located in /etc/shiny-server/shiny-server.conf. Comment out the entire file and add the following, replacing <username> with your user name and <location> with the URL location you want for your app. This will allow you to run Shiny apps from your web browser at https://your.server.edu/shiny/your-location

run as shiny;
server {
    listen 3838;
    location /<location>/ {
        run as <username>;
        site_dir /path/to/your/shiny/app;
        log_dir /var/log/shiny-server;
        directory_index on;
    }
}

For example, my configuration on the old test-pecan looks like this.

run as shiny;
server {
    listen 3838;
    location /ashiklom/ {
        run as ashiklom;
        site_dir /home/ashiklom/fs-data/pecan/shiny/;
        log_dir /var/log/shiny-server;
        directory_index on;
    }
}

…and I can access my Shiny apps at, for instance, https://test-pecan.bu.edu/shiny/ashiklom/workflowPlots.

You can add as many location <loc> { ... } fields as you would like.

run as shiny;
server {
    listen 3838;
    location /ashiklom/ {
        ...
    }
    location /bety/ {
        ...
    }
}

If you change the configuration, for example to add a new location, you will need to restart Shiny server. If you are setting up a new instance of Shiny, skip this step and continue with the guide, since there are a few more steps to get Shiny working. If there is an instance of Shiny already running, you can restart it with:

## On CentOS
sudo service shiny-server stop
sudo service shiny-server start

## On Ubuntu
sudo systemctl stop shiny-server.service
sudo systemctl start shiny-server.service

44.3 Set the Apache proxy

Create a file with the following name, based on the version of the operating system you are using:

  • Ubuntu 16.04 (pecan1, pecan2, test-pecan) – /etc/apache2/conf-available/shiny.conf
  • CentOS 6.5 (psql-pecan) – /etc/httpd/conf.d/shiny.conf

Into this file, add the following:

ProxyPass           /shiny/ http://localhost:3838/
ProxyPassReverse    /shiny/ http://localhost:3838/
RedirectMatch permanent ^/shiny$ /shiny/

44.3.1 Ubuntu only: Enable the new shiny configuration

sudo a2enconf shiny

This will create a symbolic link to the newly created shiny.conf file inside the /etc/apache2/conf-enabled directory. You can do ls -l /etc/apache2/conf-enabled to confirm that this worked.

44.4 Enable and start the shiny server, and restart apache

44.4.1 On CentOS

sudo ln -s /opt/shiny-server/config/init.d/redhat/shiny-server /etc/init.d
sudo service shiny-server stop
sudo service shiny-server start
sudo service httpd restart

You can check that Shiny is running with service shiny-server status.

44.4.2 On Ubuntu

Enable the Shiny server service. This will make sure Shiny runs automatically on startup.

sudo systemctl enable shiny-server.service

Restart Apache.

sudo apachectl restart

Start the Shiny server.

sudo systemctl start shiny-server.service

If there are problems, you can stop the shiny-server.service with…

sudo systemctl stop shiny-server.service

…and then use start again to restart it.

44.5 Troubleshooting

Refer to the log files for shiny (/var/log/shiny-server.log) and httpd (on CentOS, /var/log/httpd/error-log; on Ubuntu, /var/log/apache2/error-log).