install_dependencies.sh

#!/bin/bash

# This script installs the dependencies for the pbsweb application.
# The script should be run as a normal, unprivileged user that has sudo rights.
# This will ensure that the python virtual environments and the web application 
# does not run as root, and has minimal privileges.
#
# Usage: 
#
#   $ ./install_dependencies.sh
#
# You can run this script again at any time.

###############
# Configuration
###############

html='/var/www/html'
apps='/var/www/wsgi/apps'
confs='/var/www/wsgi/confs'
envs='/var/www/wsgi/virtualenvs'

# This is the Python version that will be installed in the virtual environments.
# This version of Python needs to be already available in your system.
python=python3.8

# System packages to be installed via dnf.
packages="nginx python38-devel openssl-devel swig"

###########
# Functions
###########

function usage {
    echo "Usage: $0"
    echo "There are no options for this script."
    echo "You cannot run this script directly as root."
    echo "You need to be able to sudo though."
    echo ""
}

function will_install {
    # Show the user what will be installed by this script.
    echo "This script will perform the following:"
    echo -n "  Install system packages:"
    for p in $packages; do
        echo -n "  $p"
    done
    echo ""
    echo "  Install a systemd service \"emperor.uwsgi.service\" if not already installed."
    echo "  Create directories /run/uwsgi and /var/www/wsgi"
    echo "  Copy configuration files to /etc/nginx/ & /var/www/wsgi/ & /etc/logrotate.d/"
    echo "  Copy an example PBS Status page into /var/www/html/"
    echo "  Install two $python environments under $envs"
    echo ""
}

function check_sudo {
    # Function to check if a user can sudo.
    local sudo_prompt

    sudo_prompt=$(sudo -nv 2>&1)
    if [ $? -eq 0 ]; then
        echo "Your sudo access is currently valid."
        return 0
    fi

    echo $sudo_prompt | grep -q '^sudo:'
    if [ $? -eq 0 ]; then
        echo "Please enter your password to use sudo."
        sudo -v
        return 0
    fi
    echo "You do not have sudo"
}

########
# Checks
########

echo ""
echo "-------------------------------------------"
echo "Install Dependencies for PBSWeb Application"
echo "-------------------------------------------"
echo ""

# Check number of args is zero
if [ $# -gt 0 ]; then
    usage
    exit 0;
fi

# Check user is not running this script as root.
if [[ $EUID -eq 0 ]]; then
   echo "You should NOT be root to run this script."
   echo "You should run it as an unprivileged user that has sudo rights."
   echo "Exiting"
   echo ""
   exit 0
fi
this_user="$USER"

# Check that the required Python version exists on this system."
which $python > /dev/null 2>&1
if [ $? -ne 0 ]; then
    echo "Could not find the required Python version on this system."
    echo "The required version of Python is: $python"
    echo "Try to install this version of Python and run this script again."
    echo "Exiting."
    exit 0
fi

# Show the user what will be installed by this script.
will_install

# Check user really wants to install.
read -r -p "Type \"y\" to install. Any other key will exit: " REPLY
if [[ ! $REPLY =~ ^[Yy]$ ]]; then
    echo "exiting"
    exit 0
fi

################
# Do the install
################

# Check this unprivileged user has sudo rights.
check_sudo

echo "Installing system packages ..."
for p in $packages; do
    echo "  $p"
    sudo dnf -qy install $p
done

# If there is no existing emperor service then copy this one into place.
# We will not start it. The user should enable/start it manually.
if [ ! -f /etc/systemd/system/emperor.uwsgi.service ]; then
    echo "Installing new systemd service: emperor.uwsgi.service"
    sudo cp confs/emperor.uwsgi.service /etc/systemd/system/
else
    echo "Not overwriting existing systemd service: emperor.uwsgi.service"
fi

echo "Creating directory /run/uwsgi for the web sockets."
sudo mkdir -p /run/uwsgi
sudo chown nginx:nginx /run/uwsgi

echo "Creating directory /var/www/wsgi for the web apps."
sudo mkdir -p /var/www/wsgi
sudo chown $this_user:$this_user /var/www/wsgi

# Underneath /var/www/wsgi the directories will be owned 
# by the user running this script.
for dir in $apps $confs $envs; do 
    if [ ! -d $dir ]; then
        echo "creating $dir"
        mkdir -p $dir
    fi
done

echo "Copying PBSWeb configuration files for Nginx into /etc/nginx/"
if [[ -f /etc/nginx/nginx.conf && ! -f /etc/nginx/nginx.conf_ORIGINAL ]]; then
    echo "Once only backup of existing nginx.conf to nginx.conf_ORIGINAL"
    sudo cp /etc/nginx/nginx.conf /etc/nginx/nginx.conf_ORIGINAL
fi
sudo cp confs/nginx.conf /etc/nginx/
sudo cp confs/nginx_default.conf /etc/nginx/conf.d/default.conf
sudo cp confs/nginx_pbsweb.conf /etc/nginx/conf.d/pbsweb.conf
sudo cp confs/nginx_pbsweb_test.conf /etc/nginx/conf.d/pbsweb_test.conf_OFF

echo "Copying UWSGI configuration file into /var/www/wsgi/"
sudo cp confs/emperor.ini /var/www/wsgi/

echo "Copying UWSGI log rotate file into /etc/logrotate.d/"
sudo cp confs/logrotate_uwsgi /etc/logrotate.d/uwsgi

echo "Copying example PBS Status page into /var/www/html/"
sudo cp src/static/pbsweb.html /var/www/html/

# Start nginx and check that there are no errors.
sudo systemctl start nginx
if [ $? -ne 0 ]; then
    # An error has occurred. Warn the user and continue the install.
    echo "  ERROR: nginx failed to start. Check the status of your nginx web server."
    echo "  The installation will continue."
fi

echo "Creating $python virtual environments."
# Running these steps again does not raise any errors.
$python -m venv ${envs}/emperor --prompt="emperor"
$python -m venv ${envs}/pbsweb  --prompt="pbsweb"

# For each of these virtual environments install required packages
# and create a requirements file.

source ${envs}/emperor/bin/activate
python -m pip -q install --upgrade pip
for package in pip-review uwsgi; do
    pip -q install $package
done
pip freeze > ${envs}/requirements_emperor.txt
echo "UWSGI version = $(uwsgi --version)"
deactivate

source ${envs}/pbsweb/bin/activate
python -m pip -q install --upgrade pip
for package in pip-review bottle Jinja2; do
    pip -q install $package
done
pip freeze > ${envs}/requirements_pbsweb.txt
deactivate

echo ""
echo "The dependencies for pbs have now been installed."
echo "You should now run ./swig_compile_pbs.sh"
echo "Then run ./install_pbsweb.sh"
echo ""