#!/bin/bash
# Usage: "./Linux - Update TRMM agent.sh" update amd64
# 
# Description:
#   This script can be used to download the latest version of a Tactical RMM agent, compile it and replace/update it. 
#   Preferrably this script is run in combination with the scheduling script that can be found under Task scripts in this repository.
#
# Arguments:
#   update - Used to specify that the agent needs to be updated
#   [SystemType] - Specify what type of system the agent needs to be updated on ('amd64' 'x86' 'arm64' 'armv6')
#
# Author: D. de Kooker (info@dcomputers.nl)
# Sources: https://github.com/netvolt/LinuxRMM-Script/blob/main/rmmagent-linux.sh
# Changelog: 
#   06-09-2023 - Change the script from source to exclude the Install and uninstall part, 
#                adjusted it so it could be run on it's own (or by scheduled task script with TRMM) to update a linux agent. 

check_zip=$(which unzip 2> /dev/null)
if [[ $check_zip == "" || $check_zip =~ .*"no unzip".* ]]; then
        echo "unzip could not be found. Trying to install automatically."
        if [[ `which yum` ]]; then
                yum -y install unzip
                echo "Unzip installed. Continue script..."
        elif [[ `which apt` ]]; then
                apt-get -y update
                apt-get -y install unzip
                echo "Unzip installed. Continue script..."
        else
                echo "unzip could not be installed. Please install unzip manually."
        fi
        exit 1
fi

if [[ $1 == "" ]]; then
        echo "First argument is empty !"
        echo "Type help for more information"
        exit 1
fi

if [[ $1 == "help" ]]; then
        echo "There is help but more information is available at github.com/ZoLuSs/rmmagent-script"
        echo ""
        echo "List of UPDATE argument (no argument name)"
        echo "Arg 1: 'update'"
        echo "Arg 2: System type 'amd64' 'x86' 'arm64' 'armv6'"
        echo ""
        echo ""
        exit 0
fi

if [[ $1 != "update" ]]; then
        echo "First argument can only be 'update' !"
        echo "Type help for more information"
        exit 1
fi

if [[ $1 == "update" && $2 == "" ]]; then
        echo "Argument 2 (System type) is empty !"
        echo "Type help for more information"
        exit 1
fi

## Setting var for easy scription
system=$2
go_version="1.22.1"

go_url_amd64="https://go.dev/dl/go$go_version.linux-amd64.tar.gz"
go_url_x86="https://go.dev/dl/go$go_version.linux-386.tar.gz"
go_url_arm64="https://go.dev/dl/go$go_version.linux-arm64.tar.gz"
go_url_armv6="https://go.dev/dl/go$go_version.linux-armv6l.tar.gz"

function check_profile () {
        source /etc/environment
        profile_file="/root/.profile"
        path_count=$(cat $profile_file | grep -o "export PATH=/usr/local/go/bin" | wc -l)
        if [[ $path_count -ne 0 ]]; then
                echo "Removing incorrect \$PATH variable\(s\)"
                sed -i "/export\ PATH\=\/usr\/local\/go\/bin/d" $profile_file
        fi

        path_count=$(cat $profile_file | grep -o "export PATH=\$PATH:/usr/local/go/bin" | wc -l)
        if [[ $path_count -ne 1 ]]; then
                echo "Fixing \$PATH Variable"
                sed -i "/export\ PATH\=\$PATH\:\/usr\/local\/go\/bin/d" $profile_file
                echo "export PATH=\$PATH:/usr/local/go/bin" >> $profile_file
        fi
        source $profile_file
}

function go_install() {
        if ! command -v go &> /dev/null; then
                ## Installing golang
                case $system in
                amd64)
                wget -O /tmp/golang.tar.gz $go_url_amd64
                        ;;
                x86)
                wget -O /tmp/golang.tar.gz $go_url_x86
                ;;
                arm64)
                wget -O /tmp/golang.tar.gz $go_url_arm64
                ;;
                armv6)
                wget -O /tmp/golang.tar.gz $go_url_armv6
                ;;
                esac
                
                rm -rvf /usr/local/go/
                tar -xvzf /tmp/golang.tar.gz -C /usr/local/
                rm /tmp/golang.tar.gz
                export GOPATH=/usr/local/go
                export GOCACHE=/root/.cache/go-build

                echo "Go is installed (version $go_current_version)."
        else
                # Get the current version of Go installed
                go_current_version=$(go version | awk '{print $3}' | sed 's/go//')

                if [ "$go_current_version" != "$go_version" ]; then
                        echo "Version mismatch. Current installed version is $go_current_version. Desired version is $go_version."
                        echo "Installing Go $go_version..."
                        ## Installing golang
                        case $system in
                        amd64)
                        wget -O /tmp/golang.tar.gz $go_url_amd64
                                ;;
                        x86)
                        wget -O /tmp/golang.tar.gz $go_url_x86
                        ;;
                        arm64)
                        wget -O /tmp/golang.tar.gz $go_url_arm64
                        ;;
                        armv6)
                        wget -O /tmp/golang.tar.gz $go_url_armv6
                        ;;
                        esac

                        rm -rvf /usr/local/go/
                        tar -xvzf /tmp/golang.tar.gz -C /usr/local/
                        rm /tmp/golang.tar.gz
                        export GOPATH=/usr/local/go
                        export GOCACHE=/root/.cache/go-build

                        echo "Go $go_version installed."
                else
                        echo "Go is up to date (version $go_current_version)."
                fi
        fi
}

function agent_compile() {
        ## Compiling and installing tactical agent from github
        echo "Agent Compile begin"
        wget -O /tmp/rmmagent.zip "https://github.com/amidaware/rmmagent/archive/refs/heads/master.zip"
        unzip /tmp/rmmagent -d /tmp/
        rm /tmp/rmmagent.zip
        cd /tmp/rmmagent-master
        case $system in
        amd64)
          env CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags "-s -w" -o /tmp/temp_rmmagent
        ;;
        x86)
          env CGO_ENABLED=0 GOOS=linux GOARCH=386 go build -ldflags "-s -w" -o /tmp/temp_rmmagent
        ;;
        arm64)
          env CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -ldflags "-s -w" -o /tmp/temp_rmmagent
        ;;
        armv6)
          env CGO_ENABLED=0 GOOS=linux GOARCH=arm go build -ldflags "-s -w" -o /tmp/temp_rmmagent
        ;;
        esac
        
        cd /tmp
        rm -R /tmp/rmmagent-master
}

function update_agent() {
        systemctl stop tacticalagent

        cp /tmp/temp_rmmagent /usr/local/bin/rmmagent
        rm /tmp/temp_rmmagent

        systemctl start tacticalagent
}

case $1 in
update)
        check_profile
        go_install
        agent_compile
        update_agent
        echo "Tactical Agent Update is done"
        exit 0;;
esac