bash: Install Postgres Database for usage in LAN

postgres_install.sh

#!/bin/bash

DB_USER="admin"
DB_PASSWORD=$(openssl rand -base64 16)
DB_NAME="connectors"
DB_HOST=$(hostname -I | awk '{print $1}')

# Ensure PostgreSQL listens on all interfaces
configure_postgresql() {
    sudo sed -i "s/^#listen_addresses = 'localhost'/listen_addresses = '*'/" /var/lib/pgsql/data/postgresql.conf
    echo "host    all             all             0.0.0.0/0               md5" | sudo tee -a /var/lib/pgsql/data/pg_hba.conf
    sudo systemctl restart postgresql
}

# Check if user exists
check_user() {
    sudo -u postgres psql -tc "SELECT 1 FROM pg_roles WHERE rolname='$DB_USER';" | grep -q 1
}

# Check if database exists
check_db() {
    sudo -u postgres psql -tc "SELECT 1 FROM pg_database WHERE datname='$DB_NAME';" | grep -q 1
}

# Create user and database only if they don't exist
create_user_and_db() {
    check_user || sudo -u postgres psql -c "CREATE ROLE $DB_USER WITH LOGIN PASSWORD '$DB_PASSWORD';"
    check_db || sudo -u postgres psql -c "CREATE DATABASE $DB_NAME OWNER $DB_USER;"
    sudo -u postgres psql -c "ALTER ROLE $DB_USER WITH CREATEDB;"
    sudo -u postgres psql -c "GRANT ALL PRIVILEGES ON DATABASE $DB_NAME TO $DB_USER;"
}

# Verify if PostgreSQL is listening on 0.0.0.0
verify_listening() {
    if ss -tulnp | grep ":5432" | grep -q "0.0.0.0"; then
        echo "✅ PostgreSQL is listening on all interfaces."
    else
        echo "❌ PostgreSQL is NOT listening on all interfaces."
        exit 1
    fi
}

# Apply fixes
configure_postgresql
create_user_and_db
verify_listening

echo "✅ PostgreSQL setup completed."
echo "🔗 Connection String:"
echo "   postgresql://$DB_USER:$DB_PASSWORD@$DB_HOST:5432/$DB_NAME"