Preparing The Raspberry Pi

First, we need to start by loading a fresh image of Raspbian Stretch Lite onto our SD card (I recommend at least 32GB class 10), you can download it from the official Raspbian site.

Although not mandatory, I recommend performing the following actions using the sudo raspi-config application:

• Expand Filesystem (Advanced Options / Expand Filesystem).
• Reduce GPU memory to 16MB (Advanced Options / Memory Split).
• Disable “Predictable network interfaces” (Network Options / Network interface names).

I also recommend using a wired internet connection and disabling the onboard wifi/Bluetooth module. You can disable it persistently by editing this file: sudo nano /boot/config.txt, by adding these two lines:

dtoverlay=pi3-disable-bt
dtoverlay=pi3-disable-wifi

Next, we need to set a static IP for our Raspberry Pi, edit this file: sudo nano /etc/dhcpcd.conf, accordingly with your own needs. This is a sample IP configuration:

# Sample static IP configuration:
interface eth0
static ip_address=192.168.1.101/24
#static ip6_address=fd51:42f8:caae:d92e::ff/64
static routers=192.168.1.1
static domain_name_servers=192.168.1.1 8.8.8.8 fd51:42f8:caae:d92e::1

Enable all the repositories by uncommenting all lines in this file: sudo nano /etc/apt/sources.list and then perform the mandatory updates with this command sudo apt update && sudo apt full-upgrade.

You have to add at least 1GB of swap memory for this installation but you are going to need more, later for installing/compiling some R libraries, so with 3GB would be fine, you can do it with these commands:

sudo /bin/dd if=/dev/zero of=/var/swap.1 bs=1M count=3072
sudo /sbin/mkswap /var/swap.1
sudo /sbin/swapon /var/swap.1
sudo sh -c 'echo "/var/swap.1 swap swap defaults 0 0 " >> /etc/fstab'

Prevent the unnecessary use of swap memory for protecting your SD card:

sudo nano /etc/sysctl.conf
# Add this at the end
    vm.swappiness=10

Setting Up The Server

For convenience, we need an HTML server and Nginx is a really good option because of its reduced requirements. You can install Nginx with these commands:

sudo apt install nginx
sudo chown -R www-data:pi /var/www/html/
sudo chmod -R 770 /var/www/html/

Then, we need a SQL server for storing and manipulating our data, I personally prefer PostgreSQL since it’s open-source and has impressive capabilities, but it´s up to you which one to choose. You can install PostgreSQL with this command:

sudo apt install postgresql libpq-dev postgresql-client postgresql-client-common

Configure PostgreSQL to accept local and remote connections by editing these files and modify/add/comment these lines:

sudo nano /etc/postgresql/9.6/main/pg_hba.conf # Edit as it follows
    local all all md5 #Modify 
    host all all 192.168.1.0/24 trust #Add
    host all all 0.0.0.0/0 password #Add

sudo nano /etc/postgresql/9.6/main/postgresql.conf # Edit as it follows
    #listen_addresses #Comment 
    listen_addresses='*' #Add 

Restart PostgreSQL service:

sudo systemctl restart postgresql

Create the pi user and database in the PostgreSQL server:

sudo su postgres
createuser pi -P --interactive
psql
create database pi;
\q
exit

Now, we get to the R specific part of the process, we are going to install the latest version of R from source with these commands:

sudo apt-get install -y gfortran libreadline6-dev libx11-dev libxt-dev \
       libpng-dev libjpeg-dev libcairo2-dev xvfb \
       libbz2-dev libzstd-dev liblzma-dev \
       libcurl4-openssl-dev \
       texinfo texlive texlive-fonts-extra \
       screen wget openjdk-8-jdk
cd /usr/local/src
sudo wget https://cran.rstudio.com/src/base/R-3/R-3.6.2.tar.gz
sudo su
tar zxvf R-3.6.2.tar.gz
cd R-3.6.2
./configure --enable-R-shlib #--with-blas --with-lapack #optional
make
make install
cd ..
rm -rf R-3.6.2*
exit
cd

❗️WARNING: EVERYTHING BEYOND THIS POINT IS EXTREMELY TIME-CONSUMING e.g. Installing RStudio from source on Raspbian can take around 27 hours ????

Installing Shiny Server

We are going to install Shiny Server from source, but first, we have to install its dependencies.

✏ It’s necessary to install R packages as superuser, for Shiny to be able to use them.

sudo su - -c "R -e \"install.packages('later', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('fs', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('Rcpp', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('httpuv', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('mime', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('jsonlite', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('digest', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('htmltools', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('xtable', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('R6', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('Cairo', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('sourcetools', repos='http://cran.rstudio.com/')\""
sudo su - -c "R -e \"install.packages('shiny', repos='http://cran.rstudio.com/')\""

Install cmake from source:

wget https://cmake.org/files/v3.15/cmake-3.15.3.tar.gz # Check for the latest version on https://cmake.org/files/
tar xzf cmake-3.15.3.tar.gz
cd cmake-3.15.3
./configure; make
sudo make install
cd

Now we can install Shiny Server with these commands:

git clone https://github.com/rstudio/shiny-server.git
cd shiny-server
DIR=`pwd`
PATH=$DIR/bin:$PATH
mkdir tmp
cd tmp
PYTHON=`which python`
sudo cmake -DCMAKE_INSTALL_PREFIX=/usr/local -DPYTHON="$PYTHON" ../
sudo make
mkdir ../build
sed -i '8s/.*/NODE_SHA256=af2106b08f68e0884caa505ea7e695facc5b4cd356f1e08258899e94cc4c5df0/' ../external/node/install-node.sh # node-v10.15.3-linux-armv7l.tar.xz
sed -i 's/linux-x64.tar.xz/linux-armv7l.tar.xz/' ../external/node/install-node.sh
(cd .. && sudo ./external/node/install-node.sh)
(cd .. && ./bin/npm --python="${PYTHON}" install --no-optional)
(cd .. && ./bin/npm --python="${PYTHON}" rebuild)
sudo make install

After installing it, you have to configure Shiny Server with these commands:

cd
sudo ln -s /usr/local/shiny-server/bin/shiny-server /usr/bin/shiny-server
sudo useradd -r -m shiny
sudo mkdir -p /var/log/shiny-server
sudo mkdir -p /srv/shiny-server
sudo mkdir -p /var/lib/shiny-server
sudo chown shiny /var/log/shiny-server
sudo mkdir -p /etc/shiny-server
cd
sudo wget \
https://raw.github.com/rstudio/shiny-server/master/config/upstart/shiny-server.conf \
-O /etc/init/shiny-server.conf
sudo chmod 777 -R /srv
# Configure shiny-server autostart 
sudo nano /lib/systemd/system/shiny-server.service # Paste the following
    #!/usr/bin/env bash
    [Unit]
    Description=ShinyServer
    [Service]
    Type=simple
    ExecStart=/usr/bin/shiny-server
    Restart=always
    # Environment="LANG=en_US.UTF-8"
    ExecReload=/bin/kill -HUP $MAINPID
    ExecStopPost=/bin/sleep 5
    RestartSec=1
    [Install]
    WantedBy=multi-user.target

sudo chown shiny /lib/systemd/system/shiny-server.service
sudo systemctl daemon-reload
sudo systemctl enable shiny-server
sudo systemctl start shiny-server

# Setting up proper user permissions:
sudo groupadd shiny-apps
sudo usermod -aG shiny-apps pi
sudo usermod -aG shiny-apps shiny
cd /srv/shiny-server
sudo chown -R pi:shiny-apps .
sudo chmod g+w .
sudo chmod g+s .

Installing Rstudio Server

We are going to install RStudio server from source, this is extremely time-consuming (around 27 hours last time I checked), so get your self something to do while the Raspberry Pi installs dependencies and compiles everything.

# Install Rust and Cargo
sudo curl https://sh.rustup.rs -sSf | sh
source $HOME/.cargo/env
# Install sentry-cli
sudo git clone https://github.com/getsentry/sentry-cli.git
sudo chown -R pi ~/sentry-cli
cd sentry-cli
cargo build
cd
sudo rm -rf sentry-cli

# Clone RStudio repository
sudo git clone https://github.com/rstudio/rstudio.git

# Avoid installing crashpad
sudo nano /home/pi/rstudio/dependencies/common/install-common
    # Comment these lines
        # ./install-crashpad
        # sudo ./install-crashpad

# Install system dependencies
cd rstudio/dependencies/linux
sudo su
./install-dependencies-stretch --exclude-qt-sdk
apt-get install -y openjdk-8-jdk
apt autoremove

# Configure Java
java -Xms1800m

# Install latest gwt compiler
cd /home/pi/rstudio
wget http://dl.google.com/closure-compiler/compiler-latest.zip
unzip compiler-latest.zip
rm COPYING README.md compiler-latest.zip
mv closure-compiler-v20*.jar /home/pi/rstudio/src/gwt/tools/compiler/compiler.jar

# Compile and install RStudio
mkdir build
cd build
cmake .. -DRSTUDIO_TARGET=Server -DCMAKE_BUILD_TYPE=Release
make install

#Configure Rstudio
cd
useradd -r rstudio-server
cp /usr/local/lib/rstudio-server/extras/init.d/debian/rstudio-server /etc/init.d/rstudio-server
chmod +x /etc/init.d/rstudio-server 
update-rc.d rstudio-server defaults
ln -f -s /usr/local/lib/rstudio-server/bin/rstudio-server /usr/sbin/rstudio-server
chmod 777 -R /usr/local/lib/R/site-library/
mkdir -p /var/run/rstudio-server
mkdir -p /var/lock/rstudio-server
mkdir -p /var/log/rstudio-server
mkdir -p /var/lib/rstudio-server
rm -rf /home/pi/rstudio
nano /etc/init.d/rstudio-server
    # Modify your PATH variable for using the compiled version of R
        # PATH=/usr/local/bin/:/sbin:/usr/sbin:/bin:/usr/bin
systemctl daemon-reload
rstudio-server start
exit

Extra Steps

Make pretty URLs for Shiny and Rstudio Server (e.g. http://your-ip/shiny/your-app instead of http://your-ip:3838/your-app) by editing Nginx config file: sudo nano /etc/nginx/sites-enabled/default and adding the following lines before the line that reads server {

map $http_upgrade $connection_upgrade {
      default upgrade;
      ''      close;
    }

Add the following lines right after the line that reads server_name _;

    rewrite ^/shiny$ $scheme://$http_host/shiny/ permanent;

    location /shiny/ {
            rewrite ^/shiny/(.*)$ /$1 break;
            proxy_pass http://localhost:3838;
            proxy_redirect / $scheme://$http_host/shiny/;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection $connection_upgrade;
            proxy_read_timeout 20d;
            proxy_buffering off;
    }
    
    rewrite ^/rstudio$ $scheme://$http_host/rstudio/ permanent; 
    
    location /rstudio/ {
        rewrite ^/rstudio/(.*)$ /$1 break;
        proxy_pass http://localhost:8787;
        proxy_redirect http://localhost:8787/ $scheme://$http_host/rstudio/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_read_timeout 20d;
    }

Now you have to restart Nginx to apply changes:

sudo service nginx restart

If you want to have access to your server from remote origins (over the internet) you must follow these extra steps:

• If you don’t have a static public IP:
  • Open an account in a Dynamic DNS Services e.g. https://www.noip.com
  • Configure Dynamic DNS in your router/modem, if you don’t have that option, you can install a DDNS client on your server.
  • Optionally configure your personal domain name to point to your DDNS service
• Configure port forwarding in your router/modem:
  • For SSH open port TCP/UDP 22~22
  • For PostgreSQL open port TCP/UDP 5432
  • For FTP open port TCP 20~21
  • For VPN open port UDP 1194
  • For HTTP open port TCP 80
• Make sure you have “Block WAN traffic” disabled on your router/modem.

And this is it, you are ready to start developing your Shiny apps and deploying it in the /srv/shiny-server folder of your own server, enjoy!

Final Comments

The major limitation of the Raspberry Pi is RAM memory, so keep in mind that you have to keep your apps simple enough so they don’t need more than 1 GB of RAM if your app requires something greater than that, it’s going to be using swap memory and that could ruin your SD card very fast.

The performance is relatively slow, especially for plotting, keep in mind that even though the Raspberry Pi 3B+ has 4 cores they are not fast ones and most of the R packages don’t use parallel computing.