install.sh

#!/bin/bash
#
# Nodecho Agent Installation Script
#
# @version		0.1.0
# @date			2024-04-14
# @copyright	(c) 2024 https://nodecho.com
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
# @date			2014-07-30
# @copyright	(c) 2014 http://nodequery.com
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

# Set environment
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

# Prepare output
echo -e "|\n|   Nodecho Installer\n|   ===================\n|"

# Root required
if [ $(id -u) != "0" ]; then
    echo -e "|   Error: You need to be root to install the Nodecho agent\n|"
    echo -e "|          The agent itself will NOT be running as root but instead under its own non-privileged user\n|"
    exit 1
fi

# Parameters required
if [ $# -lt 1 ]; then
    echo -e "|   Usage: bash $0 'token'\n|"
    exit 1
fi

# Check if crontab is installed
if [ ! -n "$(command -v crontab)" ]; then

    # Confirm crontab installation
    echo "|" && read -p "|   Crontab is required and could not be found. Do you want to install it? [Y/n] " input_variable_install

    # Attempt to install crontab
    if [ -z $input_variable_install ] || [ $input_variable_install == "Y" ] || [ $input_variable_install == "y" ]; then
        if [ -n "$(command -v apt-get)" ]; then
            echo -e "|\n|   Notice: Installing required package 'cron' via 'apt-get'"
            apt-get -y update
            apt-get -y install cron
        elif [ -n "$(command -v yum)" ]; then
            echo -e "|\n|   Notice: Installing required package 'cronie' via 'yum'"
            yum -y install cronie

            if [ ! -n "$(command -v crontab)" ]; then
                echo -e "|\n|   Notice: Installing required package 'vixie-cron' via 'yum'"
                yum -y install vixie-cron
            fi
        elif [ -n "$(command -v pacman)" ]; then
            echo -e "|\n|   Notice: Installing required package 'cronie' via 'pacman'"
            pacman -S --noconfirm cronie
        fi
    fi

    if [ ! -n "$(command -v crontab)" ]; then
        # Show error
        echo -e "|\n|   Error: Crontab is required and could not be installed\n|"
        exit 1
    fi
fi

# Check if cron is running
if [ -z "$(ps -Al | grep cron | grep -v grep)" ]; then

    # Confirm cron service
    echo "|" && read -p "|   Cron is available but not running. Do you want to start it? [Y/n] " input_variable_service

    # Attempt to start cron
    if [ -z $input_variable_service ] || [ $input_variable_service == "Y" ] || [ $input_variable_service == "y" ]; then
        if [ -n "$(command -v apt-get)" ]; then
            echo -e "|\n|   Notice: Starting 'cron' via 'service'"
            service cron start
        elif [ -n "$(command -v yum)" ]; then
            echo -e "|\n|   Notice: Starting 'crond' via 'service'"
            chkconfig crond on
            service crond start
        elif [ -n "$(command -v pacman)" ]; then
            echo -e "|\n|   Notice: Starting 'cronie' via 'systemctl'"
            systemctl start cronie
            systemctl enable cronie
        fi
    fi

    # Check if cron was started
    if [ -z "$(ps -Al | grep cron | grep -v grep)" ]; then
        # Show error
        echo -e "|\n|   Error: Cron is available but could not be started\n|"
        exit 1
    fi
fi

# Attempt to delete previous agent
if [ -f /etc/nodecho/agent.sh ]; then
    # Remove agent dir
    rm -Rf /etc/nodecho

    # Remove cron entry and user
    if id -u nodecho >/dev/null 2>&1; then
        (crontab -u nodecho -l | grep -v "/etc/nodecho/agent.sh") | crontab -u nodecho - && userdel nodecho
    else
        (crontab -u root -l | grep -v "/etc/nodecho/agent.sh") | crontab -u root -
    fi
fi

# Create agent dir
mkdir -p /etc/nodecho

# Download agent
echo -e "|   Downloading agent.sh to /etc/nodecho\n|\n|   + $(wget -nv -o /dev/stdout -O /etc/nodecho/agent.sh --no-check-certificate https://raw.github.com/NodechoHQ/nodecho-agent/main/agent.sh)"

if [ -f /etc/nodecho/agent.sh ]; then
    # Create auth file
    echo "$1" > /etc/nodecho/auth.log

    # Create user
    useradd nodecho -r -d /etc/nodecho -s /bin/false

    # Modify user permissions
    chown -R nodecho:nodecho /etc/nodecho && chmod -R 700 /etc/nodecho

    # Modify ping permissions
    chmod +s `type -p ping`

    # Configure cron
    crontab -u nodecho -l 2>/dev/null | { cat; echo "*/3 * * * * bash /etc/nodecho/agent.sh > /etc/nodecho/cron.log 2>&1"; } | crontab -u nodecho -

    # Show success
    echo -e "|\n|   Success: The Nodecho agent has been installed\n|"

    # Attempt to delete installation script
    if [ -f $0 ]; then
        rm -f $0
    fi
else
    # Show error
    echo -e "|\n|   Error: The Nodecho agent could not be installed\n|"
fi