install_exporters.sh

#!/bin/bash
# Prometheus Exporters install script for RHEL/CentOS based environment
# Always the latest exporter versions will be installed!

DEFAULT_APACHE_PORT=9117
DEFAULT_NGINX_PORT=9113
DEFAULT_PHPFPM_PORT=9001
DEFAULT_SYSTEM_PORT=9100

check_selinux() {
    if sestatus | grep -q "enabled"; then
        echo "SELinux is enabled, adjusting contexts..."
        SELINUX_ENABLED=true
    else
        SELINUX_ENABLED=false
    fi
}

adjust_selinux_context() {
    local binary_path=$1
    sudo semanage fcontext -a -t bin_t $binary_path
    sudo restorecon -v $binary_path
}

install_apache_exporter() {
    local port=${1:-$DEFAULT_APACHE_PORT}

    if ! command -v wget &> /dev/null; then
        echo "wget is required but not installed. Please install wget."
        exit 1
    fi

    latest_version=$(curl -s https://api.github.com/repos/Lusitaniae/apache_exporter/releases/latest | grep -oP '"tag_name": "\K(.*)(?=")')
    download_url=$(curl -s https://api.github.com/repos/Lusitaniae/apache_exporter/releases/latest | grep browser_download_url | grep linux-amd64.tar.gz | cut -d '"' -f 4)

    wget "$download_url" -O /tmp/apache_exporter.tar.gz

    tar xvf /tmp/apache_exporter.tar.gz -C /tmp/

    extracted_dir=$(tar -tf /tmp/apache_exporter.tar.gz | head -n 1 | cut -d "/" -f 1)

    sudo mv "/tmp/$extracted_dir/apache_exporter" /usr/local/bin/

    rm -rf /tmp/apache_exporter.tar.gz "/tmp/$extracted_dir"

    sudo chmod 755 /usr/local/bin/apache_exporter
    sudo chown apache:apache /usr/local/bin/apache_exporter

    if [ "$SELINUX_ENABLED" = true ]; then
        adjust_selinux_context /usr/local/bin/apache_exporter
    fi

    cat <<EOF | sudo tee /etc/systemd/system/apache_exporter.service >/dev/null
[Unit]
Description=Apache Exporter
Wants=network-online.target
After=network-online.target

[Service]
User=apache
Group=apache
Type=simple
ExecStart=/usr/local/bin/apache_exporter --insecure --scrape_uri=http://localhost/server-status/?auto --telemetry.endpoint=/metrics --web.listen-address=:${port}

[Install]
WantedBy=multi-user.target
EOF

    sudo systemctl daemon-reload
    sudo systemctl enable apache_exporter
    sudo systemctl start apache_exporter

    echo "Apache exporter has been installed and configured to run as a service on port $port."
}

install_nginx_exporter() {
    local port=${1:-$DEFAULT_NGINX_PORT}

    sudo yum install -y epel-release
    sudo yum install -y snapd
    sudo ln -s /var/lib/snapd/snap /snap
    sudo snap install nginx-prometheus-exporter

    if [ "$SELINUX_ENABLED" = true ]; then
        adjust_selinux_context /snap/bin/nginx-prometheus-exporter
    fi

    cat <<EOF | sudo tee /etc/systemd/system/nginx_exporter.service >/dev/null
[Unit]
Description=Nginx Exporter
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
ExecStart=/snap/bin/nginx-prometheus-exporter --nginx.scrape-uri=http://127.0.0.1:8080/stub_status --web.listen-address=:$port

[Install]
WantedBy=multi-user.target
EOF

    sudo systemctl daemon-reload
    sudo systemctl enable nginx_exporter
    sudo systemctl start nginx_exporter

    echo "Nginx exporter has been installed and configured to run as a service on port $port."
}

install_phpfpm_exporter() {
    local port=${1:-$DEFAULT_PHPFPM_PORT}

    latest_version=$(curl -sI https://github.com/hipages/php-fpm_exporter/releases/latest | grep -i location | awk -F'/' '{print $NF}' | tr -d '\r\n[:space:]')
    version_without_v=${latest_version#?}
    download_url="https://github.com/hipages/php-fpm_exporter/releases/download/$latest_version/php-fpm_exporter_${version_without_v}_linux_amd64.tar.gz"

    temp_dir=$(mktemp -d)

    wget "$download_url" -O "$temp_dir/php-fpm_exporter.tar.gz"
    tar -xzvf "$temp_dir/php-fpm_exporter.tar.gz" -C "$temp_dir"

    sudo mv "$temp_dir/php-fpm_exporter" /usr/local/bin/
    chmod a+x /usr/local/bin/php-fpm_exporter

    rm -rf "$temp_dir"

    if [ "$SELINUX_ENABLED" = true ]; then
        adjust_selinux_context /usr/local/bin/php-fpm_exporter
    fi

    cat <<EOF | sudo tee /etc/systemd/system/php-fpm_exporter.service >/dev/null
[Unit]
Description=PHP-FPM Exporter
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
ExecStart=/usr/local/bin/php-fpm_exporter server --phpfpm.scrape-uri unix:///var/opt/zend/php80zend/run/php-fpm/www.sock;/status --web.listen-address=":$port"

[Install]
WantedBy=multi-user.target
EOF

    sudo systemctl daemon-reload
    sudo systemctl enable php-fpm_exporter
    sudo systemctl start php-fpm_exporter

    echo "PHP-FPM exporter has been installed and configured to run as a service on port $port."
}

install_system_exporter() {
    local port=${1:-$DEFAULT_SYSTEM_PORT}

    echo "Downloading Node Exporter..."
    NODE_EXPORTER_VERSION=$(curl -s https://api.github.com/repos/prometheus/node_exporter/releases/latest | grep -oP '"tag_name": "\K(.*)(?=")')
    DOWNLOAD_VERSION="${NODE_EXPORTER_VERSION#v}"
    DOWNLOAD_URL="https://github.com/prometheus/node_exporter/releases/download/$NODE_EXPORTER_VERSION/node_exporter-$DOWNLOAD_VERSION.linux-amd64.tar.gz"
    
    wget "$DOWNLOAD_URL" -O /tmp/node_exporter.tar.gz
    if [ $? -ne 0 ]; then
        echo "Failed to download Node Exporter."
        exit 1
    fi

    tar -xzf /tmp/node_exporter.tar.gz -C /tmp/
    if [ $? -ne 0 ]; then
        echo "Failed to extract Node Exporter archive."
        exit 1
    fi

    sudo mv "/tmp/node_exporter-$DOWNLOAD_VERSION.linux-amd64/node_exporter" /usr/local/bin/
    if [ $? -ne 0 ]; then
        echo "Failed to move Node Exporter binary to /usr/local/bin/."
        exit 1
    fi

    rm -f /tmp/node_exporter.tar.gz
    rm -rf "/tmp/node_exporter-$DOWNLOAD_VERSION.linux-amd64"

    if ! id -u node_exporter &>/dev/null; then
        sudo useradd -rs /bin/false node_exporter
    fi

    sudo chown node_exporter:node_exporter /usr/local/bin/node_exporter
    sudo chmod 755 /usr/local/bin/node_exporter

    if [ "$SELINUX_ENABLED" = true ]; then
        adjust_selinux_context /usr/local/bin/node_exporter
    fi

    cat <<EOF | sudo tee /etc/systemd/system/node_exporter.service >/dev/null
[Unit]
Description=Node Exporter
Wants=network-online.target
After=network-online.target

[Service]
User=node_exporter
Group=node_exporter
Type=simple
ExecStart=/usr/local/bin/node_exporter --web.listen-address=:$port

[Install]
WantedBy=multi-user.target
EOF

    sudo systemctl daemon-reload
    sudo systemctl enable node_exporter
    sudo systemctl start node_exporter
    echo "System Exporter installed and started successfully on port $port."
}

remove_apache_exporter() {
    sudo systemctl stop apache_exporter
    sudo systemctl disable apache_exporter
    sudo rm /etc/systemd/system/apache_exporter.service
    sudo rm /usr/local/bin/apache_exporter
}

remove_nginx_exporter() {
    sudo systemctl stop nginx_exporter
    sudo systemctl disable nginx_exporter
    sudo rm /etc/systemd/system/nginx_exporter.service
    sudo snap remove nginx-prometheus-exporter
}

remove_phpfpm_exporter() {
    sudo systemctl stop php-fpm_exporter
    sudo systemctl disable php-fpm_exporter
    sudo rm /etc/systemd/system/php-fpm_exporter.service
    sudo rm /usr/local/bin/php-fpm_exporter
}

remove_system_exporter() {
    sudo systemctl stop node_exporter
    sudo systemctl disable node_exporter
    sudo rm /etc/systemd/system/node_exporter.service
    sudo rm /usr/local/bin/node_exporter
}

show_usage() {
    echo ""
    echo "Script for installing Prometheus exporters automatically"
    echo "Usage: $0 [--remove] [exporter1] [--port port1] [exporter2] [--port port2] ..."
    echo "Available exporters: apache nginx phpfpm system"
    echo "If no --port with port number defined, defaults will be used"
    echo "Example exporters install: $0 apache --port 1234 nginx --port 2345 phpfpm system"
    echo "Example exporters removal: $0 --remove apache phpfpm system"
    echo ""
}

main() {
    check_selinux

    if [ "$#" -eq 0 ]; then
        show_usage
        exit 1
    fi

    if [ "$1" == "--remove" ]; then
        shift
        while [ $# -gt 0 ]; do
            case $1 in
                apache)
                    remove_apache_exporter
                    ;;
                nginx)
                    remove_nginx_exporter
                    ;;
                phpfpm)
                    remove_phpfpm_exporter
                    ;;
                system)
                    remove_system_exporter
                    ;;
                *)
                    echo "Unknown exporter: $1"
                    show_usage
                    ;;
            esac
            shift
        done
    else
        while [ $# -gt 0 ]; do
            case $1 in
                apache)
                    if [[ "$2" == "--port" ]]; then
                        install_apache_exporter "$3"
                        shift 3
                    else
                        install_apache_exporter
                        shift
                    fi
                    ;;
                nginx)
                    if [[ "$2" == "--port" ]]; then
                        install_nginx_exporter "$3"
                        shift 3
                    else
                        install_nginx_exporter
                        shift
                    fi
                    ;;
                phpfpm)
                    if [[ "$2" == "--port" ]]; then
                        install_phpfpm_exporter "$3"
                        shift 3
                    else
                        install_phpfpm_exporter
                        shift
                    fi
                    ;;
                system)
                    if [[ "$2" == "--port" ]]; then
                        install_system_exporter "$3"
                        shift 3
                    else
                        install_system_exporter
                        shift
                    fi
                    ;;
                --remove)
                    shift
                    ;;
                *)
                    echo "Unknown parameter or exporter: $1"
                    show_usage
                    exit 1
                    ;;
            esac
        done
    fi
}

main "$@"