Production-Hardened MySQL 8.0 Installer for Ubuntu 20.04/22.04/24.04 WSL2 Compatible | Idempotent | SOC2/ISO27001-aligned

install-mysql.sh

#!/bin/bash
#===============================================================================
# Production-Hardened MySQL 8.0 Installer for Ubuntu 20.04/22.04/24.04
# Idempotent | Failsafe | SOC2/ISO27001-aligned
#===============================================================================

set -euo pipefail
IFS=$'\n\t'

#-------------------------------------------------------------------------------
# CONFIGURATION
#-------------------------------------------------------------------------------
readonly SCRIPT_NAME="$(basename "$0")"
readonly LOG_FILE="/var/log/${SCRIPT_NAME%.sh}.log"
readonly BACKUP_DIR="/root/mysql-backup-$(date +%Y%m%d-%H%M%S)"
readonly MYSQL_CONFIG_DIR="/etc/mysql/mysql.conf.d"
readonly MYSQLD_CNF="${MYSQL_CONFIG_DIR}/99-production-hardening.cnf"

# Minimum system requirements
readonly MIN_RAM_MB=1024
readonly MIN_DISK_MB=2048

#-------------------------------------------------------------------------------
# LOGGING
#-------------------------------------------------------------------------------
exec > >(tee -a "${LOG_FILE}") 2>&1

log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*"
}

die() {
    log "❌ FATAL: $*"
    exit 1
}

#-------------------------------------------------------------------------------
# PREFLIGHT CHECKS
#-------------------------------------------------------------------------------
preflight() {
    log "🔍 Running pre-flight checks..."

    # Root check
    if [[ "${EUID:-$(id -u)}" -ne 0 ]]; then
        die "This script must be run as root or with sudo."
    fi

    # OS check
    if ! grep -qE 'Ubuntu (20|22|24)\.04' /etc/os-release 2>/dev/null; then
        log "⚠️  Warning: This script is tested on Ubuntu 20.04/22.04/24.04 only."
        read -r -p "Continue anyway? [y/N]: " confirm
        [[ "$confirm" =~ ^[Yy]$ ]] || die "Aborted by user."
    fi

    # RAM check
    local avail_ram
    avail_ram=$(free -m | awk '/^Mem:/{print $7}')
    if [[ "${avail_ram}" -lt "${MIN_RAM_MB}" ]]; then
        die "Insufficient available RAM: ${avail_ram}MB (min: ${MIN_RAM_MB}MB)"
    fi

    # Disk check
    local avail_disk
    avail_disk=$(df -m / | awk 'NR==2 {print $4}')
    if [[ "${avail_disk}" -lt "${MIN_DISK_MB}" ]]; then
        die "Insufficient disk space on /: ${avail_disk}MB (min: ${MIN_DISK_MB}MB)"
    fi

    # Check for MariaDB conflict
    if dpkg -l | grep -qE '^ii\s+mariadb'; then
        die "MariaDB is installed. MySQL and MariaDB conflict. Remove MariaDB first."
    fi

    log "✅ Pre-flight checks passed."
}

#-------------------------------------------------------------------------------
# PASSWORD INPUT WITH STRENGTH VALIDATION
#-------------------------------------------------------------------------------
prompt_password() {
    local var_name="$1"
    local prompt_text="$2"
    local confirm_text="$3"
    local min_length="${4:-16}"

    local pass1 pass2

    while true; do
        read -r -s -p "${prompt_text}: " pass1
        echo ""
        read -r -s -p "${confirm_text}: " pass2
        echo ""

        if [[ -z "$pass1" ]]; then
            log "⚠️  Password cannot be empty."
            continue
        fi

        if [[ "${#pass1}" -lt "${min_length}" ]]; then
            log "⚠️  Password must be at least ${min_length} characters."
            continue
        fi

        if [[ "$pass1" != "$pass2" ]]; then
            log "❌ Passwords do not match."
            continue
        fi

        # Basic entropy check
        if ! [[ "$pass1" =~ [A-Z] && "$pass1" =~ [a-z] && "$pass1" =~ [0-9] && "$pass1" =~ [[:punct:]] ]]; then
            log "⚠️  Password must contain uppercase, lowercase, digit, and special character."
            continue
        fi

        printf -v "$var_name" '%s' "$pass1"
        break
    done
}

#-------------------------------------------------------------------------------
# INSTALLATION (Idempotent: Skips if package is installed)
#-------------------------------------------------------------------------------
install_mysql() {
    if dpkg -l | grep -qE '^ii\s+mysql-server'; then
        log "📦 MySQL server package is already installed. Skipping installation step."
        return 0
    fi

    log "🛠️  Installing MySQL Server..."
    export DEBIAN_FRONTEND=noninteractive
    apt-get update -y

    local mysql_version
    mysql_version=$(apt-cache policy mysql-server 2>/dev/null | grep Candidate | awk '{print $2}' | cut -d'-' -f1 | cut -d':' -f2 | cut -d'.' -f1-2 || echo "0")

    if [[ "$mysql_version" == "8.0" ]]; then
        log "📦 Using distribution-provided MySQL 8.0..."
        apt-get install -y mysql-server mysql-client
    else
        log "📥 Adding official MySQL APT repository..."
        local apt_config_url
        apt_config_url=$(curl -s https://dev.mysql.com/downloads/repo/apt/ | grep -oP 'https://dev.mysql.com/get/mysql-apt-config_[^"]+_all.deb' | head -1)
        
        if [[ -z "$apt_config_url" ]]; then
            die "Could not determine latest mysql-apt-config URL."
        fi

        local deb_file="/tmp/$(basename "$apt_config_url")"
        wget -q "$apt_config_url" -O "$deb_file" || die "Failed to download MySQL APT config"

        echo "mysql-apt-config mysql-apt-config/select-server select mysql-8.0" | debconf-set-selections
        dpkg -i "$deb_file" || apt-get install -f -y
        rm -f "$deb_file"
        apt-get update -y
        apt-get install -y mysql-server mysql-client
    fi

    systemctl enable mysql
    systemctl start mysql

    local wait_count=0
    until mysqladmin ping --silent 2>/dev/null || [[ $wait_count -ge 30 ]]; do
        sleep 2
        ((wait_count++))
    done

    if ! mysqladmin ping --silent 2>/dev/null; then
        die "MySQL failed to start within 60 seconds. Check /var/log/mysql/error.log"
    fi

    log "✅ MySQL installed and running."
}

#-------------------------------------------------------------------------------
# SECURITY HARDENING (Idempotent: Uses conditional checks per command)
#-------------------------------------------------------------------------------
harden_mysql() {
    log "🔒 Applying security hardening..."

    local root_pass="$1"
    local admin_user="$2"
    local admin_pass="$3"

    local sql_file
    sql_file=$(mktemp /tmp/mysql-harden-XXXXXX.sql)
    chmod 600 "$sql_file"

    cat > "$sql_file" <<EOF
-- Safely alter root auth if not already done
ALTER USER IF EXISTS 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY '${root_pass}';

-- Create dedicated admin user if missing, or update its credentials safely
CREATE USER IF NOT EXISTS '${admin_user}'@'localhost' IDENTIFIED WITH caching_sha2_password BY '${admin_pass}';
ALTER USER '${admin_user}'@'localhost' IDENTIFIED WITH caching_sha2_password BY '${admin_pass}';
GRANT ALL PRIVILEGES ON *.* TO '${admin_user}'@'localhost' WITH GRANT OPTION;

-- Remove anonymous users
DELETE FROM mysql.user WHERE User='';

-- Remove test database
DROP DATABASE IF EXISTS test;
DELETE FROM mysql.db WHERE Db='test' OR Db='test\\_%';

-- Remove remote root access
DELETE FROM mysql.user WHERE User='root' AND Host NOT IN ('localhost', '127.0.0.1', '::1');

-- Swap root to auth_socket for local system administration convenience & security
ALTER USER IF EXISTS 'root'@'localhost' IDENTIFIED WITH auth_socket;
ALTER USER IF EXISTS '${admin_user}'@'localhost' PASSWORD EXPIRE NEVER;

FLUSH PRIVILEGES;
EOF

    # Execute SQL depending on current root authentication status
    if mysql -e "SELECT 1" &>/dev/null; then
        mysql < "$sql_file"
    else
        # Fallback if execution requires systemic root authentication pass
        mysql -u root -p"${root_pass}" --batch < "$sql_file" 2>/dev/null || mysql -u root --batch < "$sql_file"
    fi

    rm -f "$sql_file"

    # Fixed: Load timezone data natively using host zoneinfo maps safely
    log "🌍 Verifying system timezone tables inside MySQL..."
    mysql_tzinfo_to_sql /usr/share/zoneinfo 2>/dev/null | mysql -u root mysql || log "⚠️  Timezone population skipped or already processed."

    # Store credentials securely using mysql_config_editor
    local login_path="production_admin"
    mysql_config_editor remove --login-path="${login_path}" 2>/dev/null || true
    mysql_config_editor set --login-path="${login_path}" --host=localhost --user="${admin_user}" --password <<< "${admin_pass}"

    log "✅ Security hardening complete."
}

#-------------------------------------------------------------------------------
# PRODUCTION CONFIGURATION
#-------------------------------------------------------------------------------
configure_production() {
    log "⚙️  Applying production configuration..."

    mkdir -p "${MYSQL_CONFIG_DIR}"
    cat > "${MYSQLD_CNF}" <<'EOF'
[mysqld]
# Network Security
bind-address            = 127.0.0.1
mysqlx-bind-address     = 127.0.0.1
skip-symbolic-links
local_infile            = 0

# Authentication
default_authentication_plugin = caching_sha2_password

# Logging (for audit and debugging)
log_error               = /var/log/mysql/error.log
general_log             = OFF
slow_query_log          = ON
slow_query_log_file     = /var/log/mysql/slow.log
long_query_time         = 2

# Binary logging (required for replication and point-in-time recovery)
server-id               = 1
log_bin                 = /var/log/mysql/mysql-bin
binlog_expire_logs_seconds = 604800  # 7 days
max_binlog_size         = 100M

# InnoDB Tuning (conservative defaults, adjust for your RAM)
innodb_buffer_pool_size = 256M
innodb_log_file_size    = 64M
innodb_flush_log_at_trx_commit = 2
innodb_flush_method     = O_DIRECT

# Connection limits
max_connections         = 151
wait_timeout            = 28800
interactive_timeout     = 28800

# Charset
character-set-server    = utf8mb4
collation-server        = utf8mb4_0900_ai_ci

# Security
require_secure_transport = OFF  # Set ON after SSL certs are configured
EOF

    mkdir -p /var/log/mysql
    chown mysql:mysql /var/log/mysql
    chmod 750 /var/log/mysql
    chmod 644 "${MYSQLD_CNF}"

    # Restart gracefully to implement rules
    systemctl restart mysql

    local wait_count=0
    until mysqladmin ping --silent 2>/dev/null || [[ $wait_count -ge 30 ]]; do
        sleep 2
        ((wait_count++))
    done

    if ! mysqladmin ping --silent 2>/dev/null; then
        die "MySQL failed to restart after configuration changes."
    fi

    log "✅ Production configuration applied."
}

#-------------------------------------------------------------------------------
# SYSTEM HARDENING
#-------------------------------------------------------------------------------
harden_system() {
    log "🛡️  Applying system-level hardening..."

    if ufw status | grep -q "Status: active"; then
        ufw deny 3306/tcp || true
        ufw allow from 127.0.0.1 to any port 3306 proto tcp || true
        log "✅ UFW rule verified: 3306 restricted to localhost."
    fi

    cat > /etc/logrotate.d/mysql-custom <<'EOF'
/var/log/mysql/*.log {
    daily
    rotate 14
    compress
    missingok
    notifempty
    create 640 mysql adm
    sharedscripts
    postrotate
        test -x /usr/bin/mysqladmin || exit 0
        if /usr/bin/mysqladmin ping > /dev/null 2>&1; then
            /usr/bin/mysqladmin flush-logs
        fi
    endscript
}
EOF

    if [[ -f /etc/apt/apt.conf.d/50unattended-upgrades ]]; then
        if ! grep -q "mysql" /etc/apt/apt.conf.d/50unattended-upgrades; then
            sed -i 's/Unattended-Upgrade::Allowed-Origins {/Unattended-Upgrade::Allowed-Origins {\n\t\t"LP-PPA-mysql-8.0:${distro_codename}";\n\t\t"Ubuntu:${distro_codename}-security";/' /etc/apt/apt.conf.d/50unattended-upgrades || true
        fi
    fi

    chmod 750 /var/lib/mysql
    chown -R mysql:mysql /var/lib/mysql

    log "✅ System hardening complete."
}

#-------------------------------------------------------------------------------
# POST-INSTALL VERIFICATION
#-------------------------------------------------------------------------------
verify_installation() {
    log "🔍 Running post-install verification..."

    local admin_user="$1"

    systemctl is-active --quiet mysql || die "MySQL service is not active."
    ss -tlnp | grep -q "127.0.0.1:3306" || die "MySQL not bound to 127.0.0.1:3306"

    local root_auth
    root_auth=$(mysql -u root -e "SELECT plugin FROM mysql.user WHERE user='root' AND host='localhost';" 2>/dev/null | tail -1 || true)
    if [[ "$root_auth" != "auth_socket" ]]; then
        log "⚠️  Warning: root@localhost is not using auth_socket."
    fi

    local admin_count
    admin_count=$(mysql -u root -e "SELECT COUNT(*) FROM mysql.user WHERE user='${admin_user}' AND host='localhost';" 2>/dev/null | tail -1 || true)
    if [[ "$admin_count" != "1" ]]; then
        die "Admin user '${admin_user}' was not created successfully."
    fi

    local anon_count
    anon_count=$(mysql -u root -e "SELECT COUNT(*) FROM mysql.user WHERE user='';" 2>/dev/null | tail -1 || true)
    if [[ "$anon_count" != "0" ]]; then
        die "Anonymous users still exist."
    fi

    log "✅ All verification checks passed."
}

#-------------------------------------------------------------------------------
# MAIN
#-------------------------------------------------------------------------------
main() {
    log "===================================================="
    log "   🛡️  Production MySQL 8.0 Installer (Idempotent)"
    log "===================================================="

    preflight

    echo ""
    log "🔐 Configure MySQL root password..."
    prompt_password MY_ROOT_PASS "Enter strong root password" "Confirm root password" 16

    echo ""
    log "👤 Configure dedicated Admin User..."
    while true; do
        read -r -p "Enter admin username [admin]: " ADMIN_USER
        ADMIN_USER=${ADMIN_USER:-admin}
        if [[ -z "$ADMIN_USER" || "$ADMIN_USER" == "root" ]]; then
            log "⚠️  Invalid username. Cannot be empty or 'root'."
        elif [[ "$ADMIN_USER" =~ [^a-zA-Z0-9_] ]]; then
            log "⚠️  Username must contain only letters, numbers, and underscores."
        else
            break
        fi
    done

    prompt_password ADMIN_PASS "Enter admin password" "Confirm admin password" 16

    if [[ "$MY_ROOT_PASS" == "$ADMIN_PASS" ]]; then
        die "Root and admin passwords must be different."
    fi

    install_mysql
    harden_mysql "$MY_ROOT_PASS" "$ADMIN_USER" "$ADMIN_PASS"
    configure_production
    harden_system
    verify_installation "$ADMIN_USER"

    MY_ROOT_PASS="CLEARED"
    ADMIN_PASS="CLEARED"
    unset MY_ROOT_PASS ADMIN_PASS

    log ""
    log "===================================================="
    log "🎉 MySQL Configuration Maintained/Deployed successfully!"
    log ""
    log "🔐 ROOT ACCESS:"
    log "   sudo mysql                    # OS auth only"
    log "   (Network root auth is DISABLED)"
    log ""
    log "👤 ADMIN ACCESS:"
    log "   mysql -u ${ADMIN_USER} -p"
    log ""
    log "📁 LOGS:"
    log "   ${LOG_FILE}"
    log "   /var/log/mysql/error.log"
    log ""
    log "⚠️  NEXT STEPS:"
    log "   1. Configure SSL: set require_secure_transport=ON after placing certs"
    log "   2. Adjust innodb_buffer_pool_size to 70% of RAM in:"
    log "      ${MYSQLD_CNF}"
    log "   3. Set up automated backups (e.g., Percona XtraBackup)"
    log "   4. Configure monitoring (Prometheus mysqld_exporter / Datadog)"
    log "===================================================="
}

main "$@"

Connecting Securely via DBeaver

1. Local

MySQL 8.0 uses a highly secure authentication plugin (caching_sha2_password) by default, which is exactly what your hardening script configured.

When you try to connect via DBeaver locally, MySQL requires an encrypted password transfer. If DBeaver doesn't have the server's public key cached locally yet, it tries to fetch it from the server. Because your script locked down connections, MySQL aggressively blocks this raw public key request for security, resulting in the "Public Key Retrieval is not allowed" error.

Fortunately, you don't need to change anything on your server to fix this. You just need to flip one toggle inside DBeaver.

How to Fix It in DBeaver

Assuming you already created MySQL connection on DBeaver.

1. Open DBeaver.
2. Right-click your MySQL connection in the left-hand navigation panel and select Edit Connection.
3. In the settings window that opens, look at the left sidebar and click on Connection settings -> Driver properties.
4. In the main panel, you will see a long, alphabetized list of properties. Scroll down (or use the filter box at the top) to find allowPublicKeyRetrieval.
5. Click on the value column next to it (which is currently blank or false) and change it to true.
6. While you are there, look right above or below it for useSSL and ensure it is set to false (since your script currently has require_secure_transport = OFF until you install real SSL certificates).
7. Click Test Connection at the bottom.

2. Remote

Because your database is locked tightly to 127.0.0.1 and protected by a local firewall rule, you cannot point DBeaver directly at your server's public IP address. Instead, you must bridge into the server securely using an SSH Tunnel.

Connection Settings Matrix

Create a new MySQL connection profile inside DBeaver and complete the following two configuration tabs:

1. Main Connection Settings Tab

Parameter	Setting	Context
Host	localhost	Crucial: Do not put your server IP here. Leave it exactly as localhost because DBeaver will evaluate this path from inside the server after tunneling.
Port	3306	Default MySQL communications port.
Database	mysql	The core administrative system schema.
Username	admin	The custom administrative user created during execution.
Password	••••••••••••	The corresponding admin password.

2. SSH Connection Tab

Check the box labeled "Use SSH Tunnel" and fill out your host environment properties:

Parameter	Setting
Connection Method	Key Pair (Recommended) or Password
Host/IP	Your server's actual public-facing IP address.
Port	22 (Or your custom SSH server port).
Username	Your server's SSH login user (e.g., root or ubuntu).
Passphrase / Password	Your system account SSH passphrase or password.

Click Test Connection at the bottom of the DBeaver configuration prompt. The terminal interface will securely piggyback across your encrypted SSH boundary and initialize your database session safely.

// secured for documentation

// secured for documentation

// secured for documentation

// secured for documentation

// secured for documentation